rnd-20051208-1-src
[rocksndiamonds.git] / src / game.c
index 5e5fe3ea5af646bd18f97feac68c7080dbb91366..1c606b528b6888d76720480a64b8cd0c9c8447cd 100644 (file)
 #include "tape.h"
 #include "network.h"
 
-/* this switch controls how rocks move horizontally */
-#define OLD_GAME_BEHAVIOUR     FALSE
-
 /* EXPERIMENTAL STUFF */
 #define USE_NEW_AMOEBA_CODE    FALSE
 
+/* EXPERIMENTAL STUFF */
+#define USE_NEW_STUFF                  (                       * 1)
+
+#define USE_NEW_SP_SLIPPERY            (USE_NEW_STUFF          * 1)
+#define USE_NEW_COLLECT_COUNT          (USE_NEW_STUFF          * 1)
+#define USE_NEW_PLAYER_ANIM            (USE_NEW_STUFF          * 1)
+#define USE_NEW_ALL_SLIPPERY           (USE_NEW_STUFF          * 1)
+#define USE_NEW_PLAYER_SPEED           (USE_NEW_STUFF          * 1)
+
+
 /* for DigField() */
 #define DF_NO_PUSH             0
 #define DF_DIG                 1
 #define INITIAL_MOVE_DELAY_ON  0
 
 /* values for player movement speed (which is in fact a delay value) */
+#define MOVE_DELAY_MIN_SPEED   32
 #define MOVE_DELAY_NORMAL_SPEED        8
 #define MOVE_DELAY_HIGH_SPEED  4
+#define MOVE_DELAY_MAX_SPEED   1
 
+#if 0
 #define DOUBLE_MOVE_DELAY(x)   (x = (x <= MOVE_DELAY_HIGH_SPEED ? x * 2 : x))
 #define HALVE_MOVE_DELAY(x)    (x = (x >= MOVE_DELAY_HIGH_SPEED ? x / 2 : x))
+#else
+#define DOUBLE_MOVE_DELAY(x)   (x = (x < MOVE_DELAY_MIN_SPEED ? x * 2 : x))
+#define HALVE_MOVE_DELAY(x)    (x = (x > MOVE_DELAY_MAX_SPEED ? x / 2 : x))
+#endif
 #define DOUBLE_PLAYER_SPEED(p) (HALVE_MOVE_DELAY((p)->move_delay_value))
 #define HALVE_PLAYER_SPEED(p)  (DOUBLE_MOVE_DELAY((p)->move_delay_value))
 
 /* values for other actions */
 #define MOVE_STEPSIZE_NORMAL   (TILEX / MOVE_DELAY_NORMAL_SPEED)
+#define MOVE_STEPSIZE_MIN      (1)
+#define MOVE_STEPSIZE_MAX      (TILEX)
+
+#define GET_DX_FROM_DIR(d)     ((d) == MV_LEFT ? -1 : (d) == MV_RIGHT ? 1 : 0)
+#define GET_DY_FROM_DIR(d)     ((d) == MV_UP   ? -1 : (d) == MV_DOWN  ? 1 : 0)
 
 #define        INIT_GFX_RANDOM()       (SimpleRND(1000000))
 
 #define GET_NEW_PUSH_DELAY(e)  (   (element_info[e].push_delay_fixed) + \
                                 RND(element_info[e].push_delay_random))
+#define GET_NEW_DROP_DELAY(e)  (   (element_info[e].drop_delay_fixed) + \
+                                RND(element_info[e].drop_delay_random))
 #define GET_NEW_MOVE_DELAY(e)  (   (element_info[e].move_delay_fixed) + \
                                 RND(element_info[e].move_delay_random))
 #define GET_MAX_MOVE_DELAY(e)  (   (element_info[e].move_delay_fixed) + \
                                    (element_info[e].move_delay_random))
+#define GET_CHANGE_DELAY(c)    (   ((c)->delay_fixed  * (c)->delay_frames) + \
+                                RND((c)->delay_random * (c)->delay_frames))
 
 #define GET_TARGET_ELEMENT(e, ch)                                      \
        ((e) == EL_TRIGGER_ELEMENT ? (ch)->actual_trigger_element :     \
         (e) == EL_TRIGGER_PLAYER  ? (ch)->actual_trigger_player : (e))
 
+#define GET_VALID_PLAYER_ELEMENT(e)                                    \
+       ((e) >= EL_PLAYER_1 && (e) <= EL_PLAYER_4 ? (e) : EL_PLAYER_1)
+
+#define CAN_GROW_INTO(e)                                               \
+       ((e) == EL_SAND || (IS_DIGGABLE(e) && level.grow_into_diggable))
+
 #define ELEMENT_CAN_ENTER_FIELD_BASE_X(x, y, condition)                        \
                (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) ||                \
                                        (condition)))
                                         IS_PLAYER(x, y) &&             \
                                         !PLAYER_ENEMY_PROTECTED(x, y))))
 
-#if 0
-#define ELEMENT_CAN_ENTER_FIELD_GENERIC(e, x, y, condition)            \
-               (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) ||                \
-                                       (condition) ||                  \
-                                       (DONT_COLLIDE_WITH(e) &&        \
-                                        IS_PLAYER(x, y) &&             \
-                                        !PLAYER_ENEMY_PROTECTED(x, y))))
-#endif
-
 #define ELEMENT_CAN_ENTER_FIELD(e, x, y)                               \
        ELEMENT_CAN_ENTER_FIELD_BASE_4(e, x, y, 0)
 
-#if 1
 #define SATELLITE_CAN_ENTER_FIELD(x, y)                                        \
        ELEMENT_CAN_ENTER_FIELD_BASE_2(EL_SATELLITE, x, y, 0)
-#else
-#define SATELLITE_CAN_ENTER_FIELD(x, y)                                        \
-       ELEMENT_CAN_ENTER_FIELD_BASE_X(x, y, Feld[x][y] == EL_ACID)
-#endif
-
-#if 0
-#define ENEMY_CAN_ENTER_FIELD(e, x, y) (IN_LEV_FIELD(x, y) && IS_FREE(x, y))
-#endif
 
 #define ENEMY_CAN_ENTER_FIELD(e, x, y)                                 \
        ELEMENT_CAN_ENTER_FIELD_BASE_2(e, x, y, 0)
 
-#if 1
-
 #define YAMYAM_CAN_ENTER_FIELD(e, x, y)                                        \
        ELEMENT_CAN_ENTER_FIELD_BASE_3(e, x, y, Feld[x][y] == EL_DIAMOND)
 
 #define SPRING_CAN_ENTER_FIELD(e, x, y)                                        \
        ELEMENT_CAN_ENTER_FIELD_BASE_2(e, x, y, 0)
 
-#else
-
-#define YAMYAM_CAN_ENTER_FIELD(e, x, y)                                        \
-               (IN_LEV_FIELD(x, y) && (IS_FREE_OR_PLAYER(x, y) ||      \
-                                       (CAN_MOVE_INTO_ACID(e) &&       \
-                                        Feld[x][y] == EL_ACID) ||      \
-                                       Feld[x][y] == EL_DIAMOND))
-
-#define DARK_YAMYAM_CAN_ENTER_FIELD(e, x, y)                           \
-               (IN_LEV_FIELD(x, y) && (IS_FREE_OR_PLAYER(x, y) ||      \
-                                       (CAN_MOVE_INTO_ACID(e) &&       \
-                                        Feld[x][y] == EL_ACID) ||      \
-                                       IS_FOOD_DARK_YAMYAM(Feld[x][y])))
-
-#define PACMAN_CAN_ENTER_FIELD(e, x, y)                                        \
-               (IN_LEV_FIELD(x, y) && (IS_FREE_OR_PLAYER(x, y) ||      \
-                                       (CAN_MOVE_INTO_ACID(e) &&       \
-                                        Feld[x][y] == EL_ACID) ||      \
-                                       IS_AMOEBOID(Feld[x][y])))
-
-#define PIG_CAN_ENTER_FIELD(e, x, y)                                   \
-               (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) ||                \
-                                       (CAN_MOVE_INTO_ACID(e) &&       \
-                                        Feld[x][y] == EL_ACID) ||      \
-                                       IS_FOOD_PIG(Feld[x][y])))
-
-#define PENGUIN_CAN_ENTER_FIELD(e, x, y)                               \
-               (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) ||                \
-                                       (CAN_MOVE_INTO_ACID(e) &&       \
-                                        Feld[x][y] == EL_ACID) ||      \
-                                       IS_FOOD_PENGUIN(Feld[x][y]) ||  \
-                                       Feld[x][y] == EL_EXIT_OPEN))
-
-#define DRAGON_CAN_ENTER_FIELD(e, x, y)                                        \
-               (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) ||                \
-                                       (CAN_MOVE_INTO_ACID(e) &&       \
-                                        Feld[x][y] == EL_ACID)))
-
-#define MOLE_CAN_ENTER_FIELD(e, x, y, condition)                       \
-               (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) ||                \
-                                       (CAN_MOVE_INTO_ACID(e) &&       \
-                                        Feld[x][y] == EL_ACID) ||      \
-                                       (condition)))
-
-#define SPRING_CAN_ENTER_FIELD(e, x, y)                                        \
-               (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) ||                \
-                                       (CAN_MOVE_INTO_ACID(e) &&       \
-                                        Feld[x][y] == EL_ACID)))
-
-#endif
-
 #define GROUP_NR(e)            ((e) - EL_GROUP_START)
 #define MOVE_ENTER_EL(e)       (element_info[e].move_enter_element)
 #define IS_IN_GROUP(e, nr)     (element_info[e].in_group[nr] == TRUE)
 #define IS_EQUAL_OR_IN_GROUP(e, ge)                                    \
        (IS_GROUP_ELEMENT(ge) ? IS_IN_GROUP(e, GROUP_NR(ge)) : (e) == (ge))
 
-#if 0
-#define CE_ENTER_FIELD_COND(e, x, y)                                   \
-               (!IS_PLAYER(x, y) &&                                    \
-                (Feld[x][y] == EL_ACID ||                              \
-                 IS_EQUAL_OR_IN_GROUP(Feld[x][y], MOVE_ENTER_EL(e))))
-#else
 #define CE_ENTER_FIELD_COND(e, x, y)                                   \
                (!IS_PLAYER(x, y) &&                                    \
                 IS_EQUAL_OR_IN_GROUP(Feld[x][y], MOVE_ENTER_EL(e)))
-#endif
 
 #define CUSTOM_ELEMENT_CAN_ENTER_FIELD(e, x, y)                                \
        ELEMENT_CAN_ENTER_FIELD_BASE_4(e, x, y, CE_ENTER_FIELD_COND(e, x, y))
 #define IN_LEV_FIELD_AND_IS_FREE(x, y)  (IN_LEV_FIELD(x, y) &&  IS_FREE(x, y))
 #define IN_LEV_FIELD_AND_NOT_FREE(x, y) (IN_LEV_FIELD(x, y) && !IS_FREE(x, y))
 
+#define ACCESS_FROM(e, d)              (element_info[e].access_direction &(d))
+#define IS_WALKABLE_FROM(e, d)         (IS_WALKABLE(e)   && ACCESS_FROM(e, d))
+#define IS_PASSABLE_FROM(e, d)         (IS_PASSABLE(e)   && ACCESS_FROM(e, d))
+#define IS_ACCESSIBLE_FROM(e, d)       (IS_ACCESSIBLE(e) && ACCESS_FROM(e, d))
+
 /* game button identifiers */
 #define GAME_CTRL_ID_STOP              0
 #define GAME_CTRL_ID_PAUSE             1
 
 /* forward declaration for internal use */
 
+static void AdvanceFrameAndPlayerCounters(int);
+
 static boolean MovePlayerOneStep(struct PlayerInfo *, int, int, int, int);
 static boolean MovePlayer(struct PlayerInfo *, int, int);
 static void ScrollPlayer(struct PlayerInfo *, int);
@@ -287,8 +245,8 @@ static void InitBeltMovement(void);
 static void CloseAllOpenTimegates(void);
 static void CheckGravityMovement(struct PlayerInfo *);
 static void CheckGravityMovementWhenNotMoving(struct PlayerInfo *);
-static void KillHeroUnlessEnemyProtected(int, int);
-static void KillHeroUnlessExplosionProtected(int, int);
+static void KillPlayerUnlessEnemyProtected(int, int);
+static void KillPlayerUnlessExplosionProtected(int, int);
 
 static void TestIfPlayerTouchesCustomElement(int, int);
 static void TestIfElementTouchesCustomElement(int, int);
@@ -299,27 +257,23 @@ static void TestIfElementSmashesCustomElement(int, int, int);
 
 static void ChangeElement(int, int, int);
 
-static boolean CheckTriggeredElementChangeExt(int, int, int, int, int,int,int);
-#define CheckTriggeredElementChange(x, y, e, ev)                       \
-       CheckTriggeredElementChangeExt(x, y, e, ev, CH_PLAYER_ANY,      \
-                                      CH_SIDE_ANY, -1)
-#define CheckTriggeredElementChangePlayer(x, y, e, ev, p, s)           \
-       CheckTriggeredElementChangeExt(x, y, e, ev, p, s, -1)
-#define CheckTriggeredElementChangeSide(x, y, e, ev, s)                        \
-       CheckTriggeredElementChangeExt(x, y, e, ev, CH_PLAYER_ANY, s, -1)
-#define CheckTriggeredElementChangePage(x, y, e, ev, p)                        \
-       CheckTriggeredElementChangeExt(x, y, e, ev, CH_PLAYER_ANY,      \
-                                      CH_SIDE_ANY, p)
-
-static boolean CheckElementChangeExt(int, int, int, int, int, int, int, int);
+static boolean CheckTriggeredElementChangeExt(int, int, int,int,int);
+#define CheckTriggeredElementChange(e, ev)                             \
+       CheckTriggeredElementChangeExt(e, ev, CH_PLAYER_ANY, CH_SIDE_ANY, -1)
+#define CheckTriggeredElementChangeByPlayer(e, ev, p, s)               \
+       CheckTriggeredElementChangeExt(e, ev, p, s, -1)
+#define CheckTriggeredElementChangeBySide(e, ev, s)                    \
+       CheckTriggeredElementChangeExt(e, ev, CH_PLAYER_ANY, s, -1)
+#define CheckTriggeredElementChangeByPage(e, ev, p)                    \
+       CheckTriggeredElementChangeExt(e, ev, CH_PLAYER_ANY, CH_SIDE_ANY, p)
+
+static boolean CheckElementChangeExt(int, int, int, int, int, int, int);
 #define CheckElementChange(x, y, e, te, ev)                            \
-       CheckElementChangeExt(x, y, e, te, ev, CH_PLAYER_ANY, CH_SIDE_ANY, -1)
-#define CheckElementChangePlayer(x, y, e, ev, p, s)                    \
-       CheckElementChangeExt(x, y, e, EL_EMPTY, ev, p, s, CH_PAGE_ANY)
-#define CheckElementChangeSide(x, y, e, te, ev, s)                     \
-       CheckElementChangeExt(x, y, e, te, ev, CH_PLAYER_ANY, s, CH_PAGE_ANY)
-#define CheckElementChangePage(x, y, e, te, ev, p)                     \
-       CheckElementChangeExt(x, y, e, te, ev, CH_PLAYER_ANY, CH_SIDE_ANY, p)
+       CheckElementChangeExt(x, y, e, te, ev, CH_PLAYER_ANY, CH_SIDE_ANY)
+#define CheckElementChangeByPlayer(x, y, e, ev, p, s)                  \
+       CheckElementChangeExt(x, y, e, EL_EMPTY, ev, p, s)
+#define CheckElementChangeBySide(x, y, e, te, ev, s)                   \
+       CheckElementChangeExt(x, y, e, te, ev, CH_PLAYER_ANY, s)
 
 static void PlayLevelSound(int, int, int);
 static void PlayLevelSoundNearest(int, int, int);
@@ -594,27 +548,46 @@ struct
   int element;
   int direction;
 }
-tube_access[] =
-{
-  { EL_TUBE_ANY,               MV_LEFT | MV_RIGHT | MV_UP | MV_DOWN },
-  { EL_TUBE_VERTICAL,                               MV_UP | MV_DOWN },
-  { EL_TUBE_HORIZONTAL,                MV_LEFT | MV_RIGHT                   },
-  { EL_TUBE_VERTICAL_LEFT,     MV_LEFT |            MV_UP | MV_DOWN },
-  { EL_TUBE_VERTICAL_RIGHT,              MV_RIGHT | MV_UP | MV_DOWN },
-  { EL_TUBE_HORIZONTAL_UP,     MV_LEFT | MV_RIGHT | MV_UP           },
-  { EL_TUBE_HORIZONTAL_DOWN,   MV_LEFT | MV_RIGHT |         MV_DOWN },
-  { EL_TUBE_LEFT_UP,           MV_LEFT |            MV_UP           },
-  { EL_TUBE_LEFT_DOWN,         MV_LEFT |                    MV_DOWN },
-  { EL_TUBE_RIGHT_UP,                    MV_RIGHT | MV_UP           },
-  { EL_TUBE_RIGHT_DOWN,                          MV_RIGHT |         MV_DOWN },
-
-  { EL_UNDEFINED,              0                                    }
+access_direction_list[] =
+{
+  { EL_TUBE_ANY,                       MV_LEFT | MV_RIGHT | MV_UP | MV_DOWN },
+  { EL_TUBE_VERTICAL,                                       MV_UP | MV_DOWN },
+  { EL_TUBE_HORIZONTAL,                        MV_LEFT | MV_RIGHT                   },
+  { EL_TUBE_VERTICAL_LEFT,             MV_LEFT |            MV_UP | MV_DOWN },
+  { EL_TUBE_VERTICAL_RIGHT,                      MV_RIGHT | MV_UP | MV_DOWN },
+  { EL_TUBE_HORIZONTAL_UP,             MV_LEFT | MV_RIGHT | MV_UP           },
+  { EL_TUBE_HORIZONTAL_DOWN,           MV_LEFT | MV_RIGHT |         MV_DOWN },
+  { EL_TUBE_LEFT_UP,                   MV_LEFT |            MV_UP           },
+  { EL_TUBE_LEFT_DOWN,                 MV_LEFT |                    MV_DOWN },
+  { EL_TUBE_RIGHT_UP,                            MV_RIGHT | MV_UP           },
+  { EL_TUBE_RIGHT_DOWN,                                  MV_RIGHT |         MV_DOWN },
+
+  { EL_SP_PORT_LEFT,                             MV_RIGHT                   },
+  { EL_SP_PORT_RIGHT,                  MV_LEFT                              },
+  { EL_SP_PORT_UP,                                                  MV_DOWN },
+  { EL_SP_PORT_DOWN,                                        MV_UP           },
+  { EL_SP_PORT_HORIZONTAL,             MV_LEFT | MV_RIGHT                   },
+  { EL_SP_PORT_VERTICAL,                                    MV_UP | MV_DOWN },
+  { EL_SP_PORT_ANY,                    MV_LEFT | MV_RIGHT | MV_UP | MV_DOWN },
+  { EL_SP_GRAVITY_PORT_LEFT,                     MV_RIGHT                   },
+  { EL_SP_GRAVITY_PORT_RIGHT,          MV_LEFT                              },
+  { EL_SP_GRAVITY_PORT_UP,                                          MV_DOWN },
+  { EL_SP_GRAVITY_PORT_DOWN,                                MV_UP           },
+  { EL_SP_GRAVITY_ON_PORT_LEFT,                          MV_RIGHT                   },
+  { EL_SP_GRAVITY_ON_PORT_RIGHT,       MV_LEFT                              },
+  { EL_SP_GRAVITY_ON_PORT_UP,                                       MV_DOWN },
+  { EL_SP_GRAVITY_ON_PORT_DOWN,                                     MV_UP           },
+  { EL_SP_GRAVITY_OFF_PORT_LEFT,                 MV_RIGHT                   },
+  { EL_SP_GRAVITY_OFF_PORT_RIGHT,      MV_LEFT                              },
+  { EL_SP_GRAVITY_OFF_PORT_UP,                                      MV_DOWN },
+  { EL_SP_GRAVITY_OFF_PORT_DOWN,                            MV_UP           },
+
+  { EL_UNDEFINED,                      MV_NO_MOVING                         }
 };
 
-static unsigned long trigger_events[MAX_NUM_ELEMENTS];
+static boolean trigger_events[MAX_NUM_ELEMENTS][NUM_CHANGE_EVENTS];
 
-#define IS_AUTO_CHANGING(e)    (element_info[e].change_events & \
-                                CH_EVENT_BIT(CE_DELAY))
+#define IS_AUTO_CHANGING(e)    (element_info[e].has_change_event[CE_DELAY])
 #define IS_JUST_CHANGING(x, y) (ChangeDelay[x][y] != 0)
 #define IS_CHANGING(x, y)      (IS_AUTO_CHANGING(Feld[x][y]) || \
                                 IS_JUST_CHANGING(x, y))
@@ -725,6 +698,19 @@ static void InitPlayerField(int x, int y, int element, boolean init_game)
                                level.sp_block_last_field :
                                level.block_last_field);
 
+    /* ---------- initialize player's last field block delay --------------- */
+
+    /* always start with reliable default value (no adjustment needed) */
+    player->block_delay_adjustment = 0;
+
+    /* special case 1: in Supaplex, Murphy blocks last field one more frame */
+    if (player->block_last_field && element == EL_SP_MURPHY)
+      player->block_delay_adjustment = 1;
+
+    /* special case 2: in game engines before 3.1.1, blocking was different */
+    if (game.use_block_last_field_bug)
+      player->block_delay_adjustment = (player->block_last_field ? -1 : 1);
+
     if (!options.network || player->connected)
     {
       player->active = TRUE;
@@ -745,6 +731,7 @@ static void InitPlayerField(int x, int y, int element, boolean init_game)
     }
 
     Feld[x][y] = EL_EMPTY;
+
     player->jx = player->last_jx = x;
     player->jy = player->last_jy = y;
   }
@@ -862,27 +849,6 @@ static void InitField(int x, int y, boolean init_game)
       GfxDir[x][y] = MovDir[x][y] = 1 << RND(4);
       break;
 
-#if 0
-    case EL_SP_EMPTY:
-      Feld[x][y] = EL_EMPTY;
-      break;
-#endif
-
-#if 0
-    case EL_EM_KEY_1_FILE:
-      Feld[x][y] = EL_EM_KEY_1;
-      break;
-    case EL_EM_KEY_2_FILE:
-      Feld[x][y] = EL_EM_KEY_2;
-      break;
-    case EL_EM_KEY_3_FILE:
-      Feld[x][y] = EL_EM_KEY_3;
-      break;
-    case EL_EM_KEY_4_FILE:
-      Feld[x][y] = EL_EM_KEY_4;
-      break;
-#endif
-
     case EL_CONVEYOR_BELT_1_SWITCH_LEFT:
     case EL_CONVEYOR_BELT_1_SWITCH_MIDDLE:
     case EL_CONVEYOR_BELT_1_SWITCH_RIGHT:
@@ -950,6 +916,10 @@ static void InitField(int x, int y, boolean init_game)
       }
       break;
   }
+
+#if USE_NEW_COLLECT_COUNT
+  Count[x][y] = element_info[Feld[x][y]].collect_count_initial;
+#endif
 }
 
 static inline void InitField_WithBug1(int x, int y, boolean init_game)
@@ -977,9 +947,10 @@ static inline void InitField_WithBug2(int x, int y, boolean init_game)
   /* this case is in fact a combination of not less than three bugs:
      first, it calls InitMovDir() for elements that can move, although this is
      already done by InitField(); then, it checks the element that was at this
-     field _before_ the call to InitField() (which can change it)
-
- */
+     field _before_ the call to InitField() (which can change it); lastly, it
+     was not called for "mole with direction" elements, which were treated as
+     "cannot move" due to (fixed) wrong element initialization in "src/init.c"
+  */
 }
 
 inline void DrawGameValue_Emeralds(int value)
@@ -992,14 +963,21 @@ inline void DrawGameValue_Dynamite(int value)
   DrawText(DX_DYNAMITE, DY_DYNAMITE, int2str(value, 3), FONT_TEXT_2);
 }
 
-inline void DrawGameValue_Keys(struct PlayerInfo *player)
+inline void DrawGameValue_Keys(int key[MAX_NUM_KEYS])
 {
   int i;
 
-  for (i = 0; i < MAX_KEYS; i++)
-    if (player->key[i])
+  /* currently only 4 of 8 possible keys are displayed */
+  for (i = 0; i < STD_NUM_KEYS; i++)
+  {
+    if (key[i])
       DrawMiniGraphicExt(drawto, DX_KEYS + i * MINI_TILEX, DY_KEYS,
                         el2edimg(EL_KEY_1 + i));
+    else
+      BlitBitmap(graphic_info[IMG_GLOBAL_DOOR].bitmap, drawto,
+                DOOR_GFX_PAGEX5 + XX_KEYS + i * MINI_TILEX, YY_KEYS,
+                MINI_TILEX, MINI_TILEY, DX_KEYS + i * MINI_TILEX, DY_KEYS);
+  }
 }
 
 inline void DrawGameValue_Score(int value)
@@ -1039,19 +1017,45 @@ inline void DrawGameValue_Level(int value)
   }
 }
 
-void DrawGameDoorValues()
+void DrawAllGameValues(int emeralds, int dynamite, int score, int time,
+                      int key_bits)
 {
+  int key[MAX_NUM_KEYS];
   int i;
 
+  for (i = 0; i < MAX_NUM_KEYS; i++)
+    key[i] = key_bits & (1 << i);
+
   DrawGameValue_Level(level_nr);
 
-  for (i = 0; i < MAX_PLAYERS; i++)
-    DrawGameValue_Keys(&stored_player[i]);
+  DrawGameValue_Emeralds(emeralds);
+  DrawGameValue_Dynamite(dynamite);
+  DrawGameValue_Score(score);
+  DrawGameValue_Time(time);
+
+  DrawGameValue_Keys(key);
+}
+
+void DrawGameDoorValues()
+{
+  int i;
+
+  if (level.game_engine_type == GAME_ENGINE_TYPE_EM)
+  {
+    DrawGameDoorValues_EM();
+
+    return;
+  }
+
+  DrawGameValue_Level(level_nr);
 
   DrawGameValue_Emeralds(local_player->gems_still_needed);
   DrawGameValue_Dynamite(local_player->inventory_size);
   DrawGameValue_Score(local_player->score);
   DrawGameValue_Time(TimeLeft);
+
+  for (i = 0; i < MAX_PLAYERS; i++)
+    DrawGameValue_Keys(stored_player[i].key);
 }
 
 static void resolve_group_element(int group_element, int recursion_depth)
@@ -1096,17 +1100,6 @@ static void resolve_group_element(int group_element, int recursion_depth)
       element_info[element].in_group[group_nr] = TRUE;
     }
   }
-
-#if 0
-  if (recursion_depth == 0 && group_element <= EL_GROUP_4)
-  {
-    printf("::: group %d: %d resolved elements\n",
-          group_element - EL_GROUP_START, group->num_elements_resolved);
-    for (i = 0; i < group->num_elements_resolved; i++)
-      printf("::: - %d ['%s']\n", group->element_resolved[i],
-            element_info[group->element_resolved[i]].token_name);
-  }
-#endif
 }
 
 
@@ -1120,12 +1113,80 @@ static void resolve_group_element(int group_element, int recursion_depth)
 
 static void InitGameEngine()
 {
-  int i, j, k;
+  int i, j, k, l;
 
   /* set game engine from tape file when re-playing, else from level file */
   game.engine_version = (tape.playing ? tape.engine_version :
                         level.game_version);
 
+  /* ---------------------------------------------------------------------- */
+  /* set flags for bugs and changes according to active game engine version */
+  /* ---------------------------------------------------------------------- */
+
+  /*
+    Summary of bugfix/change:
+    Fixed handling for custom elements that change when pushed by the player.
+
+    Fixed/changed in version:
+    3.1.0
+
+    Description:
+    Before 3.1.0, custom elements that "change when pushing" changed directly
+    after the player started pushing them (until then handled in "DigField()").
+    Since 3.1.0, these custom elements are not changed until the "pushing"
+    move of the element is finished (now handled in "ContinueMoving()").
+
+    Affected levels/tapes:
+    The first condition is generally needed for all levels/tapes before version
+    3.1.0, which might use the old behaviour before it was changed; known tapes
+    that are affected are some tapes from the level set "Walpurgis Gardens" by
+    Jamie Cullen.
+    The second condition is an exception from the above case and is needed for
+    the special case of tapes recorded with game (not engine!) version 3.1.0 or
+    above (including some development versions of 3.1.0), but before it was
+    known that this change would break tapes like the above and was fixed in
+    3.1.1, so that the changed behaviour was active although the engine version
+    while recording maybe was before 3.1.0. There is at least one tape that is
+    affected by this exception, which is the tape for the one-level set "Bug
+    Machine" by Juergen Bonhagen.
+  */
+
+  game.use_change_when_pushing_bug =
+    (game.engine_version < VERSION_IDENT(3,1,0,0) &&
+     !(tape.playing &&
+       tape.game_version >= VERSION_IDENT(3,1,0,0) &&
+       tape.game_version <  VERSION_IDENT(3,1,1,0)));
+
+  /*
+    Summary of bugfix/change:
+    Fixed handling for blocking the field the player leaves when moving.
+
+    Fixed/changed in version:
+    3.1.1
+
+    Description:
+    Before 3.1.1, when "block last field when moving" was enabled, the field
+    the player is leaving when moving was blocked for the time of the move,
+    and was directly unblocked afterwards. This resulted in the last field
+    being blocked for exactly one less than the number of frames of one player
+    move. Additionally, even when blocking was disabled, the last field was
+    blocked for exactly one frame.
+    Since 3.1.1, due to changes in player movement handling, the last field
+    is not blocked at all when blocking is disabled. When blocking is enabled,
+    the last field is blocked for exactly the number of frames of one player
+    move. Additionally, if the player is Murphy, the hero of Supaplex, the
+    last field is blocked for exactly one more than the number of frames of
+    one player move.
+
+    Affected levels/tapes:
+    (!!! yet to be determined -- probably many !!!)
+  */
+
+  game.use_block_last_field_bug =
+    (game.engine_version < VERSION_IDENT(3,1,1,0));
+
+  /* ---------------------------------------------------------------------- */
+
   /* dynamically adjust element properties according to game engine version */
   InitElementPropertiesEngine(game.engine_version);
 
@@ -1148,15 +1209,14 @@ static void InitGameEngine()
 
   /* ---------- initialize player's initial move delay --------------------- */
 
-  /* dynamically adjust player properties according to game engine version */
-  game.initial_move_delay =
-    (game.engine_version <= VERSION_IDENT(2,0,1,0) ? INITIAL_MOVE_DELAY_ON :
-     INITIAL_MOVE_DELAY_OFF);
-
   /* dynamically adjust player properties according to level information */
   game.initial_move_delay_value =
     (level.double_speed ? MOVE_DELAY_HIGH_SPEED : MOVE_DELAY_NORMAL_SPEED);
 
+  /* dynamically adjust player properties according to game engine version */
+  game.initial_move_delay = (game.engine_version <= VERSION_IDENT(2,0,1,0) ?
+                            game.initial_move_delay_value : 0);
+
   /* ---------- initialize player's initial push delay --------------------- */
 
   /* dynamically adjust player properties according to game engine version */
@@ -1181,9 +1241,10 @@ static void InitGameEngine()
       ei->change->delay_frames = 1;
     }
 
-    ei->change_events = CE_BITMASK_DEFAULT;
     for (j = 0; j < NUM_CHANGE_EVENTS; j++)
     {
+      ei->has_change_event[j] = FALSE;
+
       ei->event_page_nr[j] = 0;
       ei->event_page[j] = &ei->change_page[0];
     }
@@ -1202,14 +1263,26 @@ static void InitGameEngine()
     ei->change->change_function      = ch_delay->change_function;
     ei->change->post_change_function = ch_delay->post_change_function;
 
-    ei->change_events |= CH_EVENT_BIT(CE_DELAY);
+    ei->has_change_event[CE_DELAY] = TRUE;
 
-#if 1
     SET_PROPERTY(ch_delay->element, EP_CAN_CHANGE, TRUE);
-#endif
+    SET_PROPERTY(ch_delay->element, EP_CAN_CHANGE_OR_HAS_ACTION, TRUE);
+  }
+
+  /* ---------- initialize internal run-time variables ------------- */
+
+  for (i = 0; i < NUM_CUSTOM_ELEMENTS; i++)
+  {
+    struct ElementInfo *ei = &element_info[EL_CUSTOM_START + i];
+
+    for (j = 0; j < ei->num_change_pages; j++)
+    {
+      ei->change_page[j].can_change_or_has_action =
+       (ei->change_page[j].can_change |
+        ei->change_page[j].has_action);
+    }
   }
 
-#if 1
   /* add change events from custom element configuration */
   for (i = 0; i < NUM_CUSTOM_ELEMENTS; i++)
   {
@@ -1217,16 +1290,16 @@ static void InitGameEngine()
 
     for (j = 0; j < ei->num_change_pages; j++)
     {
-      if (!ei->change_page[j].can_change)
+      if (!ei->change_page[j].can_change_or_has_action)
        continue;
 
       for (k = 0; k < NUM_CHANGE_EVENTS; k++)
       {
        /* only add event page for the first page found with this event */
-       if (ei->change_page[j].events & CH_EVENT_BIT(k) &&
-           !(ei->change_events & CH_EVENT_BIT(k)))
+       if (ei->change_page[j].has_event[k] && !(ei->has_change_event[k]))
        {
-         ei->change_events |= CH_EVENT_BIT(k);
+         ei->has_change_event[k] = TRUE;
+
          ei->event_page_nr[k] = j;
          ei->event_page[k] = &ei->change_page[j];
        }
@@ -1234,19 +1307,6 @@ static void InitGameEngine()
     }
   }
 
-#else
-
-  /* add change events from custom element configuration */
-  for (i = 0; i < NUM_CUSTOM_ELEMENTS; i++)
-  {
-    int element = EL_CUSTOM_START + i;
-
-    /* only add custom elements that change after fixed/random frame delay */
-    if (CAN_CHANGE(element) && HAS_CHANGE_EVENT(element, CE_DELAY))
-      element_info[element].change_events |= CH_EVENT_BIT(CE_DELAY);
-  }
-#endif
-
   /* ---------- initialize run-time trigger player and element ------------- */
 
   for (i = 0; i < NUM_CUSTOM_ELEMENTS; i++)
@@ -1264,9 +1324,9 @@ static void InitGameEngine()
 
   /* initialize trigger events information */
   for (i = 0; i < MAX_NUM_ELEMENTS; i++)
-    trigger_events[i] = EP_BITMASK_DEFAULT;
+    for (j = 0; j < NUM_CHANGE_EVENTS; j++)
+      trigger_events[i][j] = FALSE;
 
-#if 1
   /* add trigger events from element change event properties */
   for (i = 0; i < MAX_NUM_ELEMENTS; i++)
   {
@@ -1274,33 +1334,32 @@ static void InitGameEngine()
 
     for (j = 0; j < ei->num_change_pages; j++)
     {
-      if (!ei->change_page[j].can_change)
+      if (!ei->change_page[j].can_change_or_has_action)
        continue;
 
-      if (ei->change_page[j].events & CH_EVENT_BIT(CE_BY_OTHER_ACTION))
+      if (ei->change_page[j].has_event[CE_BY_OTHER_ACTION])
       {
        int trigger_element = ei->change_page[j].trigger_element;
 
-       if (IS_GROUP_ELEMENT(trigger_element))
+       for (k = 0; k < NUM_CHANGE_EVENTS; k++)
        {
-         struct ElementGroupInfo *group = element_info[trigger_element].group;
+         if (ei->change_page[j].has_event[k])
+         {
+           if (IS_GROUP_ELEMENT(trigger_element))
+           {
+             struct ElementGroupInfo *group =
+               element_info[trigger_element].group;
 
-         for (k = 0; k < group->num_elements_resolved; k++)
-           trigger_events[group->element_resolved[k]]
-             |= ei->change_page[j].events;
+             for (l = 0; l < group->num_elements_resolved; l++)
+               trigger_events[group->element_resolved[l]][k] = TRUE;
+           }
+           else
+             trigger_events[trigger_element][k] = TRUE;
+         }
        }
-       else
-         trigger_events[trigger_element] |= ei->change_page[j].events;
       }
     }
   }
-#else
-  /* add trigger events from element change event properties */
-  for (i = 0; i < MAX_NUM_ELEMENTS; i++)
-    if (HAS_CHANGE_EVENT(i, CE_BY_OTHER_ACTION))
-      trigger_events[element_info[i].change->trigger_element] |=
-       element_info[i].change->events;
-#endif
 
   /* ---------- initialize push delay -------------------------------------- */
 
@@ -1330,8 +1389,11 @@ static void InitGameEngine()
     {
       if (IS_SP_ELEMENT(i))
       {
-       element_info[i].push_delay_fixed  = 6;  /* just enough to escape ... */
-       element_info[i].push_delay_random = 0;  /* ... from falling zonk     */
+       /* set SP push delay to just enough to push under a falling zonk */
+       int delay = (game.engine_version >= VERSION_IDENT(3,1,1,0) ? 8 : 6);
+
+       element_info[i].push_delay_fixed  = delay;
+       element_info[i].push_delay_random = 0;
       }
     }
   }
@@ -1351,37 +1413,36 @@ static void InitGameEngine()
     element_info[e].move_stepsize = move_stepsize_list[i].move_stepsize;
   }
 
-  /* ---------- initialize move dig/leave ---------------------------------- */
+  /* ---------- initialize collect score ----------------------------------- */
 
+  /* initialize collect score values for custom elements from initial value */
   for (i = 0; i < MAX_NUM_ELEMENTS; i++)
-  {
-    element_info[i].can_leave_element = FALSE;
-    element_info[i].can_leave_element_last = FALSE;
-  }
+    if (IS_CUSTOM_ELEMENT(i))
+      element_info[i].collect_score = element_info[i].collect_score_initial;
 
-  /* ---------- initialize gem count --------------------------------------- */
+  /* ---------- initialize collect count ----------------------------------- */
 
-  /* initialize gem count values for each element */
+  /* initialize collect count values for non-custom elements */
   for (i = 0; i < MAX_NUM_ELEMENTS; i++)
     if (!IS_CUSTOM_ELEMENT(i))
-      element_info[i].collect_count = 0;
+      element_info[i].collect_count_initial = 0;
 
-  /* add gem count values for all elements from pre-defined list */
+  /* add collect count values for all elements from pre-defined list */
   for (i = 0; collect_count_list[i].element != EL_UNDEFINED; i++)
-    element_info[collect_count_list[i].element].collect_count =
+    element_info[collect_count_list[i].element].collect_count_initial =
       collect_count_list[i].count;
 
   /* ---------- initialize access direction -------------------------------- */
 
-  /* initialize access direction values to default */
+  /* initialize access direction values to default (access from every side) */
   for (i = 0; i < MAX_NUM_ELEMENTS; i++)
     if (!IS_CUSTOM_ELEMENT(i))
       element_info[i].access_direction = MV_ALL_DIRECTIONS;
 
   /* set access direction value for certain elements from pre-defined list */
-  for (i = 0; tube_access[i].element != EL_UNDEFINED; i++)
-    element_info[tube_access[i].element].access_direction =
-      tube_access[i].direction;
+  for (i = 0; access_direction_list[i].element != EL_UNDEFINED; i++)
+    element_info[access_direction_list[i].element].access_direction =
+      access_direction_list[i].direction;
 }
 
 
@@ -1402,16 +1463,6 @@ void InitGame()
 
   InitGameEngine();
 
-#if 0
-#if DEBUG
-#if USE_NEW_AMOEBA_CODE
-  printf("Using new amoeba code.\n");
-#else
-  printf("Using old amoeba code.\n");
-#endif
-#endif
-#endif
-
   /* don't play tapes over network */
   network_playing = (options.network && !tape.playing);
 
@@ -1436,7 +1487,7 @@ void InitGame()
     player->lights_still_needed = 0;
     player->friends_still_needed = 0;
 
-    for (j = 0; j < MAX_KEYS; j++)
+    for (j = 0; j < MAX_NUM_KEYS; j++)
       player->key[j] = FALSE;
 
     player->dynabomb_count = 0;
@@ -1454,7 +1505,9 @@ void InitGame()
 
     player->use_murphy_graphic = FALSE;
 
-    player->block_last_field = FALSE;
+    player->block_last_field = FALSE;  /* initialized in InitPlayerField() */
+    player->block_delay_adjustment = 0;        /* initialized in InitPlayerField() */
+
     player->can_fall_into_acid = CAN_MOVE_INTO_ACID(player->element_nr);
 
     player->actual_frame_counter = 0;
@@ -1465,6 +1518,7 @@ void InitGame()
 
     player->is_waiting = FALSE;
     player->is_moving = FALSE;
+    player->is_auto_moving = FALSE;
     player->is_digging = FALSE;
     player->is_snapping = FALSE;
     player->is_collecting = FALSE;
@@ -1522,6 +1576,9 @@ void InitGame()
     player->switch_x = -1;
     player->switch_y = -1;
 
+    player->drop_x = -1;
+    player->drop_y = -1;
+
     player->show_envelope = 0;
 
     player->move_delay       = game.initial_move_delay;
@@ -1529,7 +1586,7 @@ void InitGame()
 
     player->move_delay_reset_counter = 0;
 
-    player->push_delay = 0;
+    player->push_delay       = -1;     /* initialized when pushing starts */
     player->push_delay_value = game.initial_push_delay_value;
 
     player->drop_delay = 0;
@@ -1552,13 +1609,14 @@ void InitGame()
 
   network_player_action_received = FALSE;
 
-#if defined(PLATFORM_UNIX)
+#if defined(NETWORK_AVALIABLE)
   /* initial null action */
   if (network_playing)
     SendToServer_MovePlayer(MV_NO_MOVING);
 #endif
 
   ZX = ZY = -1;
+  ExitX = ExitY = -1;
 
   FrameCounter = 0;
   TimeFrames = 0;
@@ -1603,15 +1661,19 @@ void InitGame()
       MovPos[x][y] = MovDir[x][y] = MovDelay[x][y] = 0;
       ChangeDelay[x][y] = 0;
       ChangePage[x][y] = -1;
+#if USE_NEW_COLLECT_COUNT
+      Count[x][y] = 0;         /* initialized in InitField() */
+#endif
       Store[x][y] = Store2[x][y] = StorePlayer[x][y] = Back[x][y] = 0;
       AmoebaNr[x][y] = 0;
       WasJustMoving[x][y] = 0;
       WasJustFalling[x][y] = 0;
+      CheckCollision[x][y] = 0;
       Stop[x][y] = FALSE;
       Pushed[x][y] = FALSE;
 
-      Changed[x][y] = CE_BITMASK_DEFAULT;
-      ChangeEvent[x][y] = CE_BITMASK_DEFAULT;
+      Changed[x][y] = FALSE;
+      ChangeEvent[x][y] = -1;
 
       ExplodePhase[x][y] = 0;
       ExplodeDelay[x][y] = 0;
@@ -1649,6 +1711,26 @@ void InitGame()
                    emulate_sb ? EMU_SOKOBAN :
                    emulate_sp ? EMU_SUPAPLEX : EMU_NONE);
 
+#if USE_NEW_ALL_SLIPPERY
+  /* initialize type of slippery elements */
+  for (i = 0; i < MAX_NUM_ELEMENTS; i++)
+  {
+    if (!IS_CUSTOM_ELEMENT(i))
+    {
+      /* default: elements slip down either to the left or right randomly */
+      element_info[i].slippery_type = SLIPPERY_ANY_RANDOM;
+
+      /* SP style elements prefer to slip down on the left side */
+      if (game.engine_version >= VERSION_IDENT(3,1,1,0) && IS_SP_ELEMENT(i))
+       element_info[i].slippery_type = SLIPPERY_ANY_LEFT_RIGHT;
+
+      /* BD style elements prefer to slip down on the left side */
+      if (game.emulation == EMU_BOULDERDASH)
+       element_info[i].slippery_type = SLIPPERY_ANY_LEFT_RIGHT;
+    }
+  }
+#endif
+
   /* initialize explosion and ignition delay */
   for (i = 0; i < MAX_NUM_ELEMENTS; i++)
   {
@@ -1664,13 +1746,8 @@ void InitGame()
       element_info[i].explosion_delay = last_phase - 1;
       element_info[i].ignition_delay = half_phase;
 
-#if 0
-      if (i == EL_BLACK_ORB)
-       element_info[i].ignition_delay = 0;
-#else
       if (i == EL_BLACK_ORB)
        element_info[i].ignition_delay = 1;
-#endif
     }
 
 #if 0
@@ -1712,6 +1789,9 @@ void InitGame()
          player->element_nr = some_player->element_nr;
 #endif
 
+         player->block_last_field       = some_player->block_last_field;
+         player->block_delay_adjustment = some_player->block_delay_adjustment;
+
          StorePlayer[jx][jy] = player->element_nr;
          player->jx = player->last_jx = jx;
          player->jy = player->last_jy = jy;
@@ -1890,7 +1970,6 @@ void InitGame()
   }
   else
   {
-#if 1
     scroll_x = (local_player->jx < SBX_Left  + MIDPOSX ? SBX_Left :
                local_player->jx > SBX_Right + MIDPOSX ? SBX_Right :
                local_player->jx - MIDPOSX);
@@ -1898,72 +1977,83 @@ void InitGame()
     scroll_y = (local_player->jy < SBY_Upper + MIDPOSY ? SBY_Upper :
                local_player->jy > SBY_Lower + MIDPOSY ? SBY_Lower :
                local_player->jy - MIDPOSY);
-#else
-    scroll_x = SBX_Left;
-    scroll_y = SBY_Upper;
-    if (local_player->jx >= SBX_Left + MIDPOSX)
-      scroll_x = (local_player->jx <= SBX_Right + MIDPOSX ?
-                 local_player->jx - MIDPOSX :
-                 SBX_Right);
-    if (local_player->jy >= SBY_Upper + MIDPOSY)
-      scroll_y = (local_player->jy <= SBY_Lower + MIDPOSY ?
-                 local_player->jy - MIDPOSY :
-                 SBY_Lower);
-#endif
   }
 
-  CloseDoor(DOOR_CLOSE_1);
+  if (!game.restart_level)
+    CloseDoor(DOOR_CLOSE_1);
 
-  DrawLevel();
-  DrawAllPlayers();
+  /* !!! FIX THIS (START) !!! */
+  if (level.game_engine_type == GAME_ENGINE_TYPE_EM)
+  {
+    InitGameEngine_EM();
+  }
+  else
+  {
+    DrawLevel();
+    DrawAllPlayers();
 
-  /* after drawing the level, correct some elements */
-  if (game.timegate_time_left == 0)
-    CloseAllOpenTimegates();
+    /* after drawing the level, correct some elements */
+    if (game.timegate_time_left == 0)
+      CloseAllOpenTimegates();
 
-  if (setup.soft_scrolling)
-    BlitBitmap(fieldbuffer, backbuffer, FX, FY, SXSIZE, SYSIZE, SX, SY);
+    if (setup.soft_scrolling)
+      BlitBitmap(fieldbuffer, backbuffer, FX, FY, SXSIZE, SYSIZE, SX, SY);
 
-  redraw_mask |= REDRAW_FROM_BACKBUFFER;
-  FadeToFront();
+    redraw_mask |= REDRAW_FROM_BACKBUFFER;
+    FadeToFront();
+  }
+  /* !!! FIX THIS (END) !!! */
 
-  /* copy default game door content to main double buffer */
-  BlitBitmap(graphic_info[IMG_GLOBAL_DOOR].bitmap, drawto,
-            DOOR_GFX_PAGEX5, DOOR_GFX_PAGEY1, DXSIZE, DYSIZE, DX, DY);
+  if (!game.restart_level)
+  {
+    /* copy default game door content to main double buffer */
+    BlitBitmap(graphic_info[IMG_GLOBAL_DOOR].bitmap, drawto,
+              DOOR_GFX_PAGEX5, DOOR_GFX_PAGEY1, DXSIZE, DYSIZE, DX, DY);
+  }
 
   DrawGameDoorValues();
 
-  UnmapGameButtons();
-  UnmapTapeButtons();
-  game_gadget[SOUND_CTRL_ID_MUSIC]->checked = setup.sound_music;
-  game_gadget[SOUND_CTRL_ID_LOOPS]->checked = setup.sound_loops;
-  game_gadget[SOUND_CTRL_ID_SIMPLE]->checked = setup.sound_simple;
-  MapGameButtons();
-  MapTapeButtons();
+  if (!game.restart_level)
+  {
+    UnmapGameButtons();
+    UnmapTapeButtons();
+    game_gadget[SOUND_CTRL_ID_MUSIC]->checked = setup.sound_music;
+    game_gadget[SOUND_CTRL_ID_LOOPS]->checked = setup.sound_loops;
+    game_gadget[SOUND_CTRL_ID_SIMPLE]->checked = setup.sound_simple;
+    MapGameButtons();
+    MapTapeButtons();
 
-  /* copy actual game door content to door double buffer for OpenDoor() */
-  BlitBitmap(drawto, bitmap_db_door,
-            DX, DY, DXSIZE, DYSIZE, DOOR_GFX_PAGEX1, DOOR_GFX_PAGEY1);
+    /* copy actual game door content to door double buffer for OpenDoor() */
+    BlitBitmap(drawto, bitmap_db_door,
+              DX, DY, DXSIZE, DYSIZE, DOOR_GFX_PAGEX1, DOOR_GFX_PAGEY1);
 
-  OpenDoor(DOOR_OPEN_ALL);
+    OpenDoor(DOOR_OPEN_ALL);
 
-  PlaySoundStereo(SND_GAME_STARTING, SOUND_MIDDLE);
+    PlaySoundStereo(SND_GAME_STARTING, SOUND_MIDDLE);
 
-  if (setup.sound_music)
-    PlayLevelMusic();
+    if (setup.sound_music)
+      PlayLevelMusic();
 
-  KeyboardAutoRepeatOffUnlessAutoplay();
+    KeyboardAutoRepeatOffUnlessAutoplay();
 
-  if (options.debug)
-  {
-    for (i = 0; i < MAX_PLAYERS; i++)
-      printf("Player %d %sactive.\n",
-            i + 1, (stored_player[i].active ? "" : "not "));
+    if (options.debug)
+    {
+      for (i = 0; i < MAX_PLAYERS; i++)
+       printf("Player %d %sactive.\n",
+              i + 1, (stored_player[i].active ? "" : "not "));
+    }
   }
 
-#if 0
-  printf("::: starting game [%d]\n", FrameCounter);
-#endif
+  game.restart_level = FALSE;
+}
+
+void UpdateEngineValues(int actual_scroll_x, int actual_scroll_y)
+{
+  /* this is used for non-R'n'D game engines to update certain engine values */
+
+  /* needed to determine if sounds are played within the visible screen area */
+  scroll_x = actual_scroll_x;
+  scroll_y = actual_scroll_y;
 }
 
 void InitMovDir(int x, int y)
@@ -2076,6 +2166,10 @@ void InitMovDir(int x, int y)
        else if (move_pattern == MV_ALONG_LEFT_SIDE ||
                 move_pattern == MV_ALONG_RIGHT_SIDE)
        {
+         /* use random direction as default start direction */
+         if (game.engine_version >= VERSION_IDENT(3,1,0,0))
+           MovDir[x][y] = 1 << RND(4);
+
          for (i = 0; i < NUM_DIRECTIONS; i++)
          {
            int x1 = x + xy[i][0];
@@ -2160,13 +2254,8 @@ void GameWon()
   if (local_player->MovPos)
     return;
 
-#if 1
   if (tape.auto_play)          /* tape might already be stopped here */
     tape.auto_play_level_solved = TRUE;
-#else
-  if (tape.playing && tape.auto_play)
-    tape.auto_play_level_solved = TRUE;
-#endif
 
   local_player->LevelSolved = FALSE;
 
@@ -2230,8 +2319,9 @@ void GameWon()
   }
 
   /* close exit door after last player */
-  if ((Feld[ExitX][ExitY] == EL_EXIT_OPEN ||
-       Feld[ExitX][ExitY] == EL_SP_EXIT_OPEN) && AllPlayersGone)
+  if (AllPlayersGone && ExitX >= 0 && ExitY >= 0 &&
+      (Feld[ExitX][ExitY] == EL_EXIT_OPEN ||
+       Feld[ExitX][ExitY] == EL_SP_EXIT_OPEN))
   {
     int element = Feld[ExitX][ExitY];
 
@@ -2241,8 +2331,10 @@ void GameWon()
     PlayLevelSoundElementAction(ExitX, ExitY, element, ACTION_CLOSING);
   }
 
-  /* Hero disappears */
-  DrawLevelField(ExitX, ExitY);
+  /* player disappears */
+  if (ExitX >= 0 && ExitY >= 0)
+    DrawLevelField(ExitX, ExitY);
+
   BackToFront();
 
   if (tape.playing)
@@ -2351,16 +2443,47 @@ int NewHiScore()
   return position;
 }
 
-void InitPlayerGfxAnimation(struct PlayerInfo *player, int action, int dir)
+inline static int getElementMoveStepsize(int x, int y)
 {
-  if (player->GfxAction != action || player->GfxDir != dir)
+  int element = Feld[x][y];
+  int direction = MovDir[x][y];
+  int dx = (direction == MV_LEFT ? -1 : direction == MV_RIGHT ? +1 : 0);
+  int dy = (direction == MV_UP   ? -1 : direction == MV_DOWN  ? +1 : 0);
+  int horiz_move = (dx != 0);
+  int sign = (horiz_move ? dx : dy);
+  int step = sign * element_info[element].move_stepsize;
+
+  /* special values for move stepsize for spring and things on conveyor belt */
+  if (horiz_move)
   {
 #if 0
-    printf("Player frame reset! (%d => %d, %d => %d)\n",
-          player->GfxAction, action, player->GfxDir, dir);
-#endif
-
-    player->GfxAction = action;
+    if (element == EL_SPRING)
+      step = sign * MOVE_STEPSIZE_NORMAL * 2;
+    else if (CAN_FALL(element) && !CAN_MOVE(element) &&
+            y < lev_fieldy - 1 && IS_BELT_ACTIVE(Feld[x][y + 1]))
+      step = sign * MOVE_STEPSIZE_NORMAL / 2;
+#else
+    if (CAN_FALL(element) &&
+       y < lev_fieldy - 1 && IS_BELT_ACTIVE(Feld[x][y + 1]))
+      step = sign * MOVE_STEPSIZE_NORMAL / 2;
+    else if (element == EL_SPRING)
+      step = sign * MOVE_STEPSIZE_NORMAL * 2;
+#endif
+  }
+
+  return step;
+}
+
+void InitPlayerGfxAnimation(struct PlayerInfo *player, int action, int dir)
+{
+  if (player->GfxAction != action || player->GfxDir != dir)
+  {
+#if 0
+    printf("Player frame reset! (%d => %d, %d => %d)\n",
+          player->GfxAction, action, player->GfxDir, dir);
+#endif
+
+    player->GfxAction = action;
     player->GfxDir = dir;
     player->Frame = 0;
     player->StepFrame = 0;
@@ -2390,21 +2513,29 @@ void InitMovingField(int x, int y, int direction)
   if (!WasJustMoving[x][y] || direction != MovDir[x][y])
     ResetGfxAnimation(x, y);
 
-  MovDir[newx][newy] = MovDir[x][y] = direction;
+  MovDir[x][y] = direction;
   GfxDir[x][y] = direction;
+  GfxAction[x][y] = (direction == MV_DOWN && CAN_FALL(element) ?
+                    ACTION_FALLING : ACTION_MOVING);
 
-  if (Feld[newx][newy] == EL_EMPTY)
-    Feld[newx][newy] = EL_BLOCKED;
+  /* this is needed for CEs with property "can move" / "not moving" */
 
-  if (direction == MV_DOWN && CAN_FALL(element))
-    GfxAction[x][y] = ACTION_FALLING;
-  else
-    GfxAction[x][y] = ACTION_MOVING;
+  if (getElementMoveStepsize(x, y) != 0)       /* moving or being moved */
+  {
+    if (Feld[newx][newy] == EL_EMPTY)
+      Feld[newx][newy] = EL_BLOCKED;
+
+    MovDir[newx][newy] = MovDir[x][y];
+
+#if USE_NEW_COLLECT_COUNT
+    Count[newx][newy] = Count[x][y];
+#endif
 
-  GfxFrame[newx][newy] = GfxFrame[x][y];
-  GfxRandom[newx][newy] = GfxRandom[x][y];
-  GfxAction[newx][newy] = GfxAction[x][y];
-  GfxDir[newx][newy] = GfxDir[x][y];
+    GfxFrame[newx][newy] = GfxFrame[x][y];
+    GfxRandom[newx][newy] = GfxRandom[x][y];
+    GfxAction[newx][newy] = GfxAction[x][y];
+    GfxDir[newx][newy] = GfxDir[x][y];
+  }
 }
 
 void Moving2Blocked(int x, int y, int *goes_to_x, int *goes_to_y)
@@ -2481,11 +2612,19 @@ static void RemoveField(int x, int y)
   MovDir[x][y] = 0;
   MovDelay[x][y] = 0;
 
+#if USE_NEW_COLLECT_COUNT
+  Count[x][y] = 0;
+#endif
+
   AmoebaNr[x][y] = 0;
   ChangeDelay[x][y] = 0;
   ChangePage[x][y] = -1;
   Pushed[x][y] = FALSE;
 
+#if 0
+  ExplodeField[x][y] = EX_TYPE_NONE;
+#endif
+
   GfxElement[x][y] = EL_UNDEFINED;
   GfxAction[x][y] = ACTION_DEFAULT;
   GfxDir[x][y] = MV_NO_MOVING;
@@ -2503,10 +2642,7 @@ void RemoveMovingField(int x, int y)
   if (IS_MOVING(x, y))
   {
     Moving2Blocked(x, y, &newx, &newy);
-#if 0
-    if (Feld[newx][newy] != EL_BLOCKED)
-      return;
-#else
+
     if (Feld[newx][newy] != EL_BLOCKED)
     {
       /* element is moving, but target field is not free (blocked), but
@@ -2521,7 +2657,6 @@ void RemoveMovingField(int x, int y)
 
       return;
     }
-#endif
   }
   else if (element == EL_BLOCKED)
   {
@@ -2568,19 +2703,10 @@ void DrawDynamite(int x, int y)
 
   frame = getGraphicAnimationFrame(graphic, GfxFrame[x][y]);
 
-#if 1
   if (Back[x][y] || Store[x][y])
     DrawGraphicThruMask(sx, sy, graphic, frame);
   else
     DrawGraphic(sx, sy, graphic, frame);
-#else
-  if (game.emulation == EMU_SUPAPLEX)
-    DrawGraphic(sx, sy, IMG_SP_DISK_RED, frame);
-  else if (Store[x][y])
-    DrawGraphicThruMask(sx, sy, graphic, frame);
-  else
-    DrawGraphic(sx, sy, graphic, frame);
-#endif
 }
 
 void CheckDynamite(int x, int y)
@@ -2598,70 +2724,23 @@ void CheckDynamite(int x, int y)
     }
   }
 
-#if 1
   StopLevelSoundActionIfLoop(x, y, ACTION_ACTIVE);
-#else
-  if (Feld[x][y] == EL_DYNAMITE_ACTIVE ||
-      Feld[x][y] == EL_SP_DISK_RED_ACTIVE)
-    StopSound(SND_DYNAMITE_ACTIVE);
-  else
-    StopSound(SND_DYNABOMB_ACTIVE);
-#endif
 
   Bang(x, y);
 }
 
-void RelocatePlayer(int x, int y, int element_raw)
+void DrawRelocatePlayer(struct PlayerInfo *player)
 {
-  int element = (element_raw == EL_SP_MURPHY ? EL_PLAYER_1 : element_raw);
-  struct PlayerInfo *player = &stored_player[element - EL_PLAYER_1];
   boolean ffwd_delay = (tape.playing && tape.fast_forward);
-  boolean no_delay = (tape.index_search);
+  boolean no_delay = (tape.warp_forward);
   int frame_delay_value = (ffwd_delay ? FfwdFrameDelay : GameFrameDelay);
   int wait_delay_value = (no_delay ? 0 : frame_delay_value);
-  int old_jx, old_jy;
-
-  if (player->GameOver)                /* do not reanimate dead player */
-    return;
-
-  RemoveField(x, y);           /* temporarily remove newly placed player */
-  DrawLevelField(x, y);
-
-  if (player->present)
-  {
-    while (player->MovPos)
-    {
-      ScrollPlayer(player, SCROLL_GO_ON);
-      ScrollScreen(NULL, SCROLL_GO_ON);
-      FrameCounter++;
-
-      DrawPlayer(player);
-
-      BackToFront();
-      Delay(wait_delay_value);
-    }
-
-    DrawPlayer(player);                /* needed here only to cleanup last field */
-    DrawLevelField(player->jx, player->jy);    /* remove player graphic */
-
-    player->is_moving = FALSE;
-  }
-
-  old_jx = player->jx;
-  old_jy = player->jy;
-
-  Feld[x][y] = element;
-  InitPlayerField(x, y, element, TRUE);
-
-  if (player != local_player)  /* do not visually relocate other players */
-    return;
+  int jx = player->jx;
+  int jy = player->jy;
 
   if (level.instant_relocation)
   {
-#if 1
     int offset = (setup.scroll_delay ? 3 : 0);
-    int jx = local_player->jx;
-    int jy = local_player->jy;
 
     if (!IN_VIS_FIELD(SCREENX(jx), SCREENY(jy)))
     {
@@ -2691,29 +2770,11 @@ void RelocatePlayer(int x, int y, int element_raw)
       if (scroll_y < SBY_Upper || scroll_y > SBY_Lower)
        scroll_y = (scroll_y < SBY_Upper ? SBY_Upper : SBY_Lower);
     }
-#else
-    scroll_x += (local_player->jx - old_jx);
-    scroll_y += (local_player->jy - old_jy);
-
-    /* don't scroll over playfield boundaries */
-    if (scroll_x < SBX_Left || scroll_x > SBX_Right)
-      scroll_x = (scroll_x < SBX_Left ? SBX_Left : SBX_Right);
-
-    /* don't scroll over playfield boundaries */
-    if (scroll_y < SBY_Upper || scroll_y > SBY_Lower)
-      scroll_y = (scroll_y < SBY_Upper ? SBY_Upper : SBY_Lower);
-#endif
 
     RedrawPlayfield(TRUE, 0,0,0,0);
   }
   else
   {
-#if 1
-#if 0
-    int offset = (setup.scroll_delay ? 3 : 0);
-    int jx = local_player->jx;
-    int jy = local_player->jy;
-#endif
     int scroll_xx = -999, scroll_yy = -999;
 
     ScrollScreen(NULL, SCROLL_GO_ON);  /* scroll last frame to full tile */
@@ -2734,13 +2795,8 @@ void RelocatePlayer(int x, int y, int element_raw)
       dx = (scroll_xx < scroll_x ? +1 : scroll_xx > scroll_x ? -1 : 0);
       dy = (scroll_yy < scroll_y ? +1 : scroll_yy > scroll_y ? -1 : 0);
 
-#if 1
       if (dx == 0 && dy == 0)          /* no scrolling needed at all */
        break;
-#else
-      if (scroll_xx == scroll_x && scroll_yy == scroll_y)
-       break;
-#endif
 
       scroll_x -= dx;
       scroll_y -= dy;
@@ -2760,76 +2816,109 @@ void RelocatePlayer(int x, int y, int element_raw)
       BackToFront();
       Delay(wait_delay_value);
     }
-#else
-    int scroll_xx = -999, scroll_yy = -999;
-
-    ScrollScreen(NULL, SCROLL_GO_ON);  /* scroll last frame to full tile */
-
-    while (scroll_xx != scroll_x || scroll_yy != scroll_y)
-    {
-      int dx = 0, dy = 0;
-      int fx = FX, fy = FY;
 
-      scroll_xx = (local_player->jx < SBX_Left  + MIDPOSX ? SBX_Left :
-                  local_player->jx > SBX_Right + MIDPOSX ? SBX_Right :
-                  local_player->jx - MIDPOSX);
+    DrawPlayer(player);
+    BackToFront();
+    Delay(wait_delay_value);
+  }
+}
 
-      scroll_yy = (local_player->jy < SBY_Upper + MIDPOSY ? SBY_Upper :
-                  local_player->jy > SBY_Lower + MIDPOSY ? SBY_Lower :
-                  local_player->jy - MIDPOSY);
+void RelocatePlayer(int jx, int jy, int el_player_raw)
+{
+  int el_player = GET_VALID_PLAYER_ELEMENT(el_player_raw);
+  struct PlayerInfo *player = &stored_player[el_player - EL_PLAYER_1];
+  boolean ffwd_delay = (tape.playing && tape.fast_forward);
+  boolean no_delay = (tape.warp_forward);
+  int frame_delay_value = (ffwd_delay ? FfwdFrameDelay : GameFrameDelay);
+  int wait_delay_value = (no_delay ? 0 : frame_delay_value);
+  int old_jx = player->jx;
+  int old_jy = player->jy;
+  int old_element = Feld[old_jx][old_jy];
+  int element = Feld[jx][jy];
+  boolean player_relocated = (old_jx != jx || old_jy != jy);
+
+  int move_dir_horiz = (jx < old_jx ? MV_LEFT : jx > old_jx ? MV_RIGHT : 0);
+  int move_dir_vert  = (jy < old_jy ? MV_UP   : jy > old_jy ? MV_DOWN  : 0);
+  int enter_side_horiz = MV_DIR_OPPOSITE(move_dir_horiz);
+  int enter_side_vert  = MV_DIR_OPPOSITE(move_dir_vert);
+  int leave_side_horiz = move_dir_horiz;
+  int leave_side_vert  = move_dir_vert;
+  int enter_side = enter_side_horiz | enter_side_vert;
+  int leave_side = leave_side_horiz | leave_side_vert;
 
-      dx = (scroll_xx < scroll_x ? +1 : scroll_xx > scroll_x ? -1 : 0);
-      dy = (scroll_yy < scroll_y ? +1 : scroll_yy > scroll_y ? -1 : 0);
+  if (player->GameOver)                /* do not reanimate dead player */
+    return;
 
-#if 1
-      if (dx == 0 && dy == 0)          /* no scrolling needed at all */
-       break;
-#else
-      if (scroll_xx == scroll_x && scroll_yy == scroll_y)
-       break;
-#endif
+  if (!player_relocated)       /* no need to relocate the player */
+    return;
 
-      scroll_x -= dx;
-      scroll_y -= dy;
+  if (IS_PLAYER(jx, jy))       /* player already placed at new position */
+  {
+    RemoveField(jx, jy);       /* temporarily remove newly placed player */
+    DrawLevelField(jx, jy);
+  }
 
-      fx += dx * TILEX / 2;
-      fy += dy * TILEY / 2;
+  if (player->present)
+  {
+    while (player->MovPos)
+    {
+      ScrollPlayer(player, SCROLL_GO_ON);
+      ScrollScreen(NULL, SCROLL_GO_ON);
 
-      ScrollLevel(dx, dy);
-      DrawAllPlayers();
+      AdvanceFrameAndPlayerCounters(player->index_nr);
 
-      /* scroll in two steps of half tile size to make things smoother */
-      BlitBitmap(drawto_field, window, fx, fy, SXSIZE, SYSIZE, SX, SY);
-      FlushDisplay();
-      Delay(wait_delay_value);
+      DrawPlayer(player);
 
-      /* scroll second step to align at full tile size */
       BackToFront();
       Delay(wait_delay_value);
     }
-#endif
+
+    DrawPlayer(player);                /* needed here only to cleanup last field */
+    DrawLevelField(player->jx, player->jy);    /* remove player graphic */
+
+    player->is_moving = FALSE;
+  }
+
+  if (IS_CUSTOM_ELEMENT(old_element))
+    CheckElementChangeByPlayer(old_jx, old_jy, old_element,
+                              CE_LEFT_BY_PLAYER,
+                              player->index_bit, leave_side);
+
+  CheckTriggeredElementChangeByPlayer(old_element, CE_PLAYER_LEAVES_X,
+                                     player->index_bit, leave_side);
+
+  Feld[jx][jy] = el_player;
+  InitPlayerField(jx, jy, el_player, TRUE);
+
+  if (!ELEM_IS_PLAYER(element))        /* player may be set on walkable element */
+  {
+    Feld[jx][jy] = element;
+    InitField(jx, jy, FALSE);
   }
+
+  if (player == local_player)  /* only visually relocate local player */
+    DrawRelocatePlayer(player);
+
+  TestIfPlayerTouchesBadThing(jx, jy);
+  TestIfPlayerTouchesCustomElement(jx, jy);
+
+  if (IS_CUSTOM_ELEMENT(element))
+    CheckElementChangeByPlayer(jx, jy, element, CE_ENTERED_BY_PLAYER,
+                              player->index_bit, enter_side);
+
+  CheckTriggeredElementChangeByPlayer(element, CE_PLAYER_ENTERS_X,
+                                     player->index_bit, enter_side);
 }
 
 void Explode(int ex, int ey, int phase, int mode)
 {
   int x, y;
-#if 0
-  int num_phase = 9;
-#endif
+  int last_phase;
+  int border_element;
 
   /* !!! eliminate this variable !!! */
   int delay = (game.emulation == EMU_SUPAPLEX ? 3 : 2);
 
-#if 1
-  int last_phase;
-#else
-  int last_phase = num_phase * delay;
-  int half_phase = (num_phase / 2) * delay;
-  int first_phase_after_start = EX_PHASE_START + 1;
-#endif
-  int border_element;
-
   if (game.explosions_delayed)
   {
     ExplodeField[ex][ey] = mode;
@@ -2840,10 +2929,6 @@ void Explode(int ex, int ey, int phase, int mode)
   {
     int center_element = Feld[ex][ey];
 
-#if 0
-    printf("::: start explosion %d,%d [%d]\n", ex, ey, FrameCounter);
-#endif
-
 #if 0
     /* --- This is only really needed (and now handled) in "Impact()". --- */
     /* do not explode moving elements that left the explode field in time */
@@ -2853,7 +2938,9 @@ void Explode(int ex, int ey, int phase, int mode)
       return;
 #endif
 
-    if (mode == EX_TYPE_NORMAL || mode == EX_TYPE_CENTER)
+    if (mode == EX_TYPE_NORMAL ||
+       mode == EX_TYPE_CENTER ||
+       mode == EX_TYPE_CROSS)
       PlayLevelSoundAction(ex, ey, ACTION_EXPLODING);
 
     /* remove things displayed in background while burning dynamite */
@@ -2868,18 +2955,7 @@ void Explode(int ex, int ey, int phase, int mode)
       Feld[ex][ey] = center_element;
     }
 
-#if 1
-
-#if 1
     last_phase = element_info[center_element].explosion_delay + 1;
-#else
-    last_phase = element_info[center_element].explosion_delay;
-#endif
-
-#if 0
-    printf("::: %d -> %d\n", center_element, last_phase);
-#endif
-#endif
 
     for (y = ey - 1; y <= ey + 1; y++) for (x = ex - 1; x <= ex + 1; x++)
     {
@@ -2887,24 +2963,10 @@ void Explode(int ex, int ey, int phase, int mode)
       int yy = y - ey + 1;
       int element;
 
-#if 1
-#if 1
       if (!IN_LEV_FIELD(x, y) ||
          (mode & EX_TYPE_SINGLE_TILE && (x != ex || y != ey)) ||
          (mode == EX_TYPE_CROSS      && (x != ex && y != ey)))
        continue;
-#else
-      if (!IN_LEV_FIELD(x, y) ||
-         (mode != EX_TYPE_NORMAL && (x != ex || y != ey)))
-       continue;
-#endif
-#else
-      if (!IN_LEV_FIELD(x, y) ||
-         ((mode != EX_TYPE_NORMAL ||
-           center_element == EL_AMOEBA_TO_DIAMOND) &&
-          (x != ex || y != ey)))
-       continue;
-#endif
 
       element = Feld[x][y];
 
@@ -2916,52 +2978,43 @@ void Explode(int ex, int ey, int phase, int mode)
          RemoveMovingField(x, y);
       }
 
-#if 1
-
-#if 0
-      if (IS_EXPLOSION_PROOF(element))
-       continue;
-#else
       /* indestructible elements can only explode in center (but not flames) */
-      if ((IS_EXPLOSION_PROOF(element) && (x != ex || y != ey)) ||
+      if ((IS_EXPLOSION_PROOF(element) && (x != ex || y != ey ||
+                                          mode == EX_TYPE_BORDER)) ||
          element == EL_FLAMES)
        continue;
-#endif
 
+      /* no idea why this was changed from 3.0.8 to 3.1.0 -- this causes buggy
+        behaviour, for example when touching a yamyam that explodes to rocks
+        with active deadly shield, a rock is created under the player !!! */
+      /* (case 1 (surely buggy): >= 3.1.0, case 2 (maybe buggy): <= 3.0.8) */
+#if 0
+      if (IS_PLAYER(x, y) && SHIELD_ON(PLAYERINFO(x, y)) &&
+         (game.engine_version < VERSION_IDENT(3,1,0,0) ||
+          (x == ex && y == ey && mode != EX_TYPE_BORDER)))
 #else
-      if ((IS_INDESTRUCTIBLE(element) &&
-          (game.engine_version < VERSION_IDENT(2,2,0,0) ||
-           (!IS_WALKABLE_OVER(element) && !IS_WALKABLE_UNDER(element)))) ||
-         element == EL_FLAMES)
-       continue;
-#endif
-
       if (IS_PLAYER(x, y) && SHIELD_ON(PLAYERINFO(x, y)))
+#endif
       {
        if (IS_ACTIVE_BOMB(element))
        {
          /* re-activate things under the bomb like gate or penguin */
-         Feld[x][y] = (Store[x][y] ? Store[x][y] : EL_EMPTY);
-         Store[x][y] = 0;
+         Feld[x][y] = (Back[x][y] ? Back[x][y] : EL_EMPTY);
+         Back[x][y] = 0;
        }
 
        continue;
       }
 
       /* save walkable background elements while explosion on same tile */
-#if 0
-      if (IS_INDESTRUCTIBLE(element))
-       Back[x][y] = element;
-#else
-      if (IS_WALKABLE(element) && IS_INDESTRUCTIBLE(element))
+      if (IS_WALKABLE(element) && IS_INDESTRUCTIBLE(element) &&
+         (x != ex || y != ey || mode == EX_TYPE_BORDER))
        Back[x][y] = element;
-#endif
 
       /* ignite explodable elements reached by other explosion */
       if (element == EL_EXPLOSION)
        element = Store2[x][y];
 
-#if 1
       if (AmoebaNr[x][y] &&
          (element == EL_AMOEBA_FULL ||
           element == EL_BD_AMOEBA ||
@@ -2972,7 +3025,6 @@ void Explode(int ex, int ey, int phase, int mode)
       }
 
       RemoveField(x, y);
-#endif
 
       if (IS_PLAYER(ex, ey) && !PLAYER_EXPLOSION_PROTECTED(ex, ey))
       {
@@ -2993,13 +3045,8 @@ void Explode(int ex, int ey, int phase, int mode)
            break;
        }
 
-#if 1
        if (PLAYERINFO(ex, ey)->use_murphy_graphic)
          Store[x][y] = EL_EMPTY;
-#else
-       if (game.emulation == EMU_SUPAPLEX)
-         Store[x][y] = EL_EMPTY;
-#endif
       }
       else if (center_element == EL_MOLE)
        Store[x][y] = EL_EMERALD_RED;
@@ -3039,48 +3086,15 @@ void Explode(int ex, int ey, int phase, int mode)
       else
        Store[x][y] = EL_EMPTY;
 
-      if (x != ex || y != ey ||
-         center_element == EL_AMOEBA_TO_DIAMOND || mode == EX_TYPE_BORDER)
+      if (x != ex || y != ey || mode == EX_TYPE_BORDER ||
+         center_element == EL_AMOEBA_TO_DIAMOND)
        Store2[x][y] = element;
 
-#if 0
-      if (AmoebaNr[x][y] &&
-         (element == EL_AMOEBA_FULL ||
-          element == EL_BD_AMOEBA ||
-          element == EL_AMOEBA_GROWING))
-      {
-       AmoebaCnt[AmoebaNr[x][y]]--;
-       AmoebaCnt2[AmoebaNr[x][y]]--;
-      }
-
-#if 1
-      RemoveField(x, y);
-#else
-      MovDir[x][y] = MovPos[x][y] = 0;
-      GfxDir[x][y] = MovDir[x][y];
-      AmoebaNr[x][y] = 0;
-#endif
-#endif
-
       Feld[x][y] = EL_EXPLOSION;
-#if 1
       GfxElement[x][y] = center_element;
-#else
-      GfxElement[x][y] = EL_UNDEFINED;
-#endif
 
       ExplodePhase[x][y] = 1;
-#if 1
       ExplodeDelay[x][y] = last_phase;
-#endif
-
-#if 0
-#if 1
-      GfxFrame[x][y] = 0;      /* animation does not start until next frame */
-#else
-      GfxFrame[x][y] = -1;     /* animation does not start until next frame */
-#endif
-#endif
 
       Stop[x][y] = TRUE;
     }
@@ -3098,18 +3112,10 @@ void Explode(int ex, int ey, int phase, int mode)
   x = ex;
   y = ey;
 
-#if 1
   if (phase == 1)
     GfxFrame[x][y] = 0;                /* restart explosion animation */
-#endif
-
-#if 0
-  printf(":X: phase == %d [%d]\n", phase, GfxFrame[x][y]);
-#endif
 
-#if 1
   last_phase = ExplodeDelay[x][y];
-#endif
 
   ExplodePhase[x][y] = (phase < last_phase ? phase + 1 : 0);
 
@@ -3117,6 +3123,7 @@ void Explode(int ex, int ey, int phase, int mode)
 
   /* activate this even in non-DEBUG version until cause for crash in
      getGraphicAnimationFrame() (see below) is found and eliminated */
+
 #endif
 #if 1
 
@@ -3131,34 +3138,20 @@ void Explode(int ex, int ey, int phase, int mode)
   }
 #endif
 
-#if 1
-
   border_element = Store2[x][y];
-  if (IS_PLAYER(x, y))
+  if (IS_PLAYER(x, y) && !PLAYER_EXPLOSION_PROTECTED(x, y))
     border_element = StorePlayer[x][y];
 
-#if 0
-  printf("::: phase == %d\n", phase);
-#endif
-
   if (phase == element_info[border_element].ignition_delay ||
       phase == last_phase)
   {
     boolean border_explosion = FALSE;
 
-#if 1
-    if (IS_PLAYER(x, y) && PLAYERINFO(x, y)->present)
-#else
-    if (IS_PLAYER(x, y))
-#endif
+    if (IS_PLAYER(x, y) && PLAYERINFO(x, y)->present &&
+       !PLAYER_EXPLOSION_PROTECTED(x, y))
     {
-      KillHeroUnlessExplosionProtected(x, y);
+      KillPlayerUnlessExplosionProtected(x, y);
       border_explosion = TRUE;
-
-#if 0
-      if (phase == last_phase)
-       printf("::: IS_PLAYER\n");
-#endif
     }
     else if (CAN_EXPLODE_BY_EXPLOSION(border_element))
     {
@@ -3166,78 +3159,25 @@ void Explode(int ex, int ey, int phase, int mode)
       Store2[x][y] = 0;
       Bang(x, y);
       border_explosion = TRUE;
-
-#if 0
-      if (phase == last_phase)
-       printf("::: CAN_EXPLODE_BY_EXPLOSION\n");
-#endif
     }
     else if (border_element == EL_AMOEBA_TO_DIAMOND)
     {
       AmoebeUmwandeln(x, y);
       Store2[x][y] = 0;
       border_explosion = TRUE;
-
-#if 0
-      if (phase == last_phase)
-       printf("::: EL_AMOEBA_TO_DIAMOND [%d, %d] [%d]\n",
-              element_info[border_element].explosion_delay,
-              element_info[border_element].ignition_delay,
-              phase);
-#endif
     }
 
-#if 1
     /* if an element just explodes due to another explosion (chain-reaction),
        do not immediately end the new explosion when it was the last frame of
        the explosion (as it would be done in the following "if"-statement!) */
     if (border_explosion && phase == last_phase)
       return;
-#endif
-  }
-
-#else
-
-  if (phase == first_phase_after_start)
-  {
-    int element = Store2[x][y];
-
-    if (element == EL_BLACK_ORB)
-    {
-      Feld[x][y] = Store2[x][y];
-      Store2[x][y] = 0;
-      Bang(x, y);
-    }
-  }
-  else if (phase == half_phase)
-  {
-    int element = Store2[x][y];
-
-    if (IS_PLAYER(x, y))
-      KillHeroUnlessExplosionProtected(x, y);
-    else if (CAN_EXPLODE_BY_EXPLOSION(element))
-    {
-      Feld[x][y] = Store2[x][y];
-      Store2[x][y] = 0;
-      Bang(x, y);
-    }
-    else if (element == EL_AMOEBA_TO_DIAMOND)
-      AmoebeUmwandeln(x, y);
   }
-#endif
 
   if (phase == last_phase)
   {
     int element;
 
-#if 0
-  printf("::: done: phase == %d\n", phase);
-#endif
-
-#if 0
-    printf("::: explosion %d,%d done [%d]\n", x, y, FrameCounter);
-#endif
-
     element = Feld[x][y] = Store[x][y];
     Store[x][y] = Store2[x][y] = 0;
     GfxElement[x][y] = EL_UNDEFINED;
@@ -3262,22 +3202,12 @@ void Explode(int ex, int ey, int phase, int mode)
     ChangeDelay[x][y] = 0;
     ChangePage[x][y] = -1;
 
-#if 1
-    InitField_WithBug2(x, y, FALSE);
-#else
-    InitField(x, y, FALSE);
-#if 1
-    /* !!! not needed !!! */
-#if 1
-    if (game.engine_version < VERSION_IDENT(3,1,0,0) &&
-       CAN_MOVE(Feld[x][y]) && Feld[x][y] != EL_MOLE)
-      InitMovDir(x, y);
-#else
-    if (CAN_MOVE(element))
-      InitMovDir(x, y);
-#endif
-#endif
+#if USE_NEW_COLLECT_COUNT
+    Count[x][y] = 0;
 #endif
+
+    InitField_WithBug2(x, y, FALSE);
+
     DrawLevelField(x, y);
 
     TestIfElementTouchesCustomElement(x, y);
@@ -3291,40 +3221,10 @@ void Explode(int ex, int ey, int phase, int mode)
     if (ELEM_IS_PLAYER(element))
       RelocatePlayer(x, y, element);
   }
-#if 1
   else if (IN_SCR_FIELD(SCREENX(x), SCREENY(y)))
-#else
-  else if (phase >= delay && IN_SCR_FIELD(SCREENX(x), SCREENY(y)))
-#endif
   {
-#if 1
     int graphic = el_act2img(GfxElement[x][y], ACTION_EXPLODING);
-#else
-    int stored = Store[x][y];
-    int graphic = (game.emulation != EMU_SUPAPLEX ? IMG_EXPLOSION :
-                  stored == EL_SP_INFOTRON ? IMG_SP_EXPLOSION_INFOTRON :
-                  IMG_SP_EXPLOSION);
-#endif
-#if 1
     int frame = getGraphicAnimationFrame(graphic, GfxFrame[x][y]);
-#else
-    int frame = getGraphicAnimationFrame(graphic, phase - delay);
-#endif
-
-#if 0
-  printf("::: phase == %d [%d]\n", phase, GfxFrame[x][y]);
-#endif
-
-#if 0
-    printf("::: %d / %d [%d - %d]\n",
-          GfxFrame[x][y], phase - delay, phase, delay);
-#endif
-
-#if 0
-    printf("::: %d ['%s'] -> %d\n", GfxElement[x][y],
-          element_info[GfxElement[x][y]].token_name,
-          graphic);
-#endif
 
     if (phase == delay)
       DrawLevelFieldCrumbledSand(x, y);
@@ -3388,11 +3288,8 @@ void DynaExplode(int ex, int ey)
 
       Explode(x, y, EX_PHASE_START, EX_TYPE_BORDER);
 
-      /* !!! extend EL_SAND to anything diggable (but maybe not SP_BASE) !!! */
-      if (element != EL_EMPTY &&
-         element != EL_SAND &&
-         element != EL_EXPLOSION &&
-         !dynabomb_xl)
+      if (element != EL_EMPTY && element != EL_EXPLOSION &&
+         !IS_DIGGABLE(element) && !dynabomb_xl)
        break;
     }
   }
@@ -3400,17 +3297,9 @@ void DynaExplode(int ex, int ey)
 
 void Bang(int x, int y)
 {
-#if 1
   int element = MovingOrBlocked2Element(x, y);
-#else
-  int element = Feld[x][y];
-#endif
 
-#if 1
   if (IS_PLAYER(x, y) && !PLAYER_EXPLOSION_PROTECTED(x, y))
-#else
-  if (IS_PLAYER(x, y))
-#endif
   {
     struct PlayerInfo *player = PLAYERINFO(x, y);
 
@@ -3418,22 +3307,6 @@ void Bang(int x, int y)
                            player->element_nr);
   }
 
-#if 0
-#if 1
-  PlayLevelSoundAction(x, y, ACTION_EXPLODING);
-#else
-  if (game.emulation == EMU_SUPAPLEX)
-    PlayLevelSound(x, y, SND_SP_ELEMENT_EXPLODING);
-  else
-    PlayLevelSound(x, y, SND_ELEMENT_EXPLODING);
-#endif
-#endif
-
-#if 0
-  if (IS_PLAYER(x, y)) /* remove objects that might cause smaller explosion */
-    element = EL_EMPTY;
-#endif
-
   switch(element)
   {
     case EL_BUG:
@@ -3460,34 +3333,27 @@ void Bang(int x, int y)
     case EL_PENGUIN:
     case EL_LAMP:
     case EL_LAMP_ACTIVE:
-#if 1
     case EL_AMOEBA_TO_DIAMOND:
-#endif
       if (IS_PLAYER(x, y))
        Explode(x, y, EX_PHASE_START, EX_TYPE_NORMAL);
       else
        Explode(x, y, EX_PHASE_START, EX_TYPE_CENTER);
       break;
     default:
-      if (CAN_EXPLODE_CROSS(element))
-#if 1
+      if (element_info[element].explosion_type == EXPLODES_CROSS)
        Explode(x, y, EX_PHASE_START, EX_TYPE_CROSS);
-#else
-       DynaExplode(x, y);
-#endif
-      else if (CAN_EXPLODE_1X1(element))
+      else if (element_info[element].explosion_type == EXPLODES_1X1)
        Explode(x, y, EX_PHASE_START, EX_TYPE_CENTER);
       else
        Explode(x, y, EX_PHASE_START, EX_TYPE_NORMAL);
       break;
   }
 
-  CheckTriggeredElementChange(x, y, element, CE_OTHER_IS_EXPLODING);
+  CheckTriggeredElementChange(element, CE_EXPLOSION_OF_X);
 }
 
 void SplashAcid(int x, int y)
 {
-#if 1
   if (IN_LEV_FIELD(x - 1, y - 1) && IS_FREE(x - 1, y - 1) &&
       (!IN_LEV_FIELD(x - 1, y - 2) ||
        !CAN_FALL(MovingOrBlocked2Element(x - 1, y - 2))))
@@ -3499,30 +3365,6 @@ void SplashAcid(int x, int y)
     Feld[x + 1][y - 1] = EL_ACID_SPLASH_RIGHT;
 
   PlayLevelSound(x, y, SND_ACID_SPLASHING);
-#else
-  /* input: position of element entering acid (obsolete) */
-
-  int element = Feld[x][y];
-
-  if (!IN_LEV_FIELD(x, y + 1) || Feld[x][y + 1] != EL_ACID)
-    return;
-
-  if (element != EL_ACID_SPLASH_LEFT &&
-      element != EL_ACID_SPLASH_RIGHT)
-  {
-    PlayLevelSound(x, y, SND_ACID_SPLASHING);
-
-    if (IN_LEV_FIELD(x - 1, y) && IS_FREE(x - 1, y) &&
-       (!IN_LEV_FIELD(x - 1, y - 1) ||
-        !CAN_FALL(MovingOrBlocked2Element(x - 1, y - 1))))
-      Feld[x - 1][y] = EL_ACID_SPLASH_LEFT;
-
-    if (IN_LEV_FIELD(x + 1, y) && IS_FREE(x + 1, y) &&
-       (!IN_LEV_FIELD(x + 1, y - 1) ||
-        !CAN_FALL(MovingOrBlocked2Element(x + 1, y - 1))))
-      Feld[x + 1][y] = EL_ACID_SPLASH_RIGHT;
-  }
-#endif
 }
 
 static void InitBeltMovement()
@@ -3710,21 +3552,15 @@ static void ToggleSwitchgateSwitch(int x, int y)
               element == EL_SWITCHGATE_OPENING)
       {
        Feld[xx][yy] = EL_SWITCHGATE_CLOSING;
-#if 1
+
        PlayLevelSoundAction(xx, yy, ACTION_CLOSING);
-#else
-       PlayLevelSound(xx, yy, SND_SWITCHGATE_CLOSING);
-#endif
       }
       else if (element == EL_SWITCHGATE_CLOSED ||
               element == EL_SWITCHGATE_CLOSING)
       {
        Feld[xx][yy] = EL_SWITCHGATE_OPENING;
-#if 1
+
        PlayLevelSoundAction(xx, yy, ACTION_OPENING);
-#else
-       PlayLevelSound(xx, yy, SND_SWITCHGATE_OPENING);
-#endif
       }
     }
   }
@@ -3776,6 +3612,10 @@ static void RedrawAllLightSwitchesAndInvisibleElements()
          Feld[x][y] = getInvisibleActiveFromInvisibleElement(element);
 
        DrawLevelField(x, y);
+
+       /* uncrumble neighbour fields, if needed */
+       if (element == EL_INVISIBLE_SAND)
+         DrawLevelFieldCrumbledSandNeighbours(x, y);
       }
       else if (element == EL_INVISIBLE_STEELWALL_ACTIVE ||
               element == EL_INVISIBLE_WALL_ACTIVE ||
@@ -3785,6 +3625,10 @@ static void RedrawAllLightSwitchesAndInvisibleElements()
          Feld[x][y] = getInvisibleFromInvisibleActiveElement(element);
 
        DrawLevelField(x, y);
+
+       /* re-crumble neighbour fields, if needed */
+       if (element == EL_INVISIBLE_SAND)
+         DrawLevelFieldCrumbledSandNeighbours(x, y);
       }
     }
   }
@@ -3834,46 +3678,15 @@ static void ActivateTimegateSwitch(int x, int y)
   Feld[x][y] = EL_TIMEGATE_SWITCH_ACTIVE;
 }
 
-inline static int getElementMoveStepsize(int x, int y)
-{
-  int element = Feld[x][y];
-  int direction = MovDir[x][y];
-  int dx = (direction == MV_LEFT ? -1 : direction == MV_RIGHT ? +1 : 0);
-  int dy = (direction == MV_UP   ? -1 : direction == MV_DOWN  ? +1 : 0);
-  int horiz_move = (dx != 0);
-  int sign = (horiz_move ? dx : dy);
-  int step = sign * element_info[element].move_stepsize;
-
-  /* special values for move stepsize for spring and things on conveyor belt */
-  if (horiz_move)
-  {
-#if 0
-    if (element == EL_SPRING)
-      step = sign * MOVE_STEPSIZE_NORMAL * 2;
-    else if (CAN_FALL(element) && !CAN_MOVE(element) &&
-            y < lev_fieldy - 1 && IS_BELT_ACTIVE(Feld[x][y + 1]))
-      step = sign * MOVE_STEPSIZE_NORMAL / 2;
-#else
-    if (CAN_FALL(element) &&
-       y < lev_fieldy - 1 && IS_BELT_ACTIVE(Feld[x][y + 1]))
-      step = sign * MOVE_STEPSIZE_NORMAL / 2;
-    else if (element == EL_SPRING)
-      step = sign * MOVE_STEPSIZE_NORMAL * 2;
-#endif
-  }
-
-  return step;
-}
-
 void Impact(int x, int y)
 {
-  boolean lastline = (y == lev_fieldy-1);
+  boolean last_line = (y == lev_fieldy - 1);
   boolean object_hit = FALSE;
-  boolean impact = (lastline || object_hit);
+  boolean impact = (last_line || object_hit);
   int element = Feld[x][y];
   int smashed = EL_STEELWALL;
 
-  if (!lastline)       /* check if element below was hit */
+  if (!last_line)      /* check if element below was hit */
   {
     if (Feld[x][y + 1] == EL_PLAYER_IS_LEAVING)
       return;
@@ -3882,10 +3695,6 @@ void Impact(int x, int y)
                                         MovDir[x][y + 1] != MV_DOWN ||
                                         MovPos[x][y + 1] <= TILEY / 2));
 
-#if 0
-    object_hit = !IS_FREE(x, y + 1);
-#endif
-
     /* do not smash moving elements that left the smashed field in time */
     if (game.engine_version >= VERSION_IDENT(2,2,0,7) && IS_MOVING(x, y + 1) &&
        ABS(MovPos[x][y + 1] + getElementMoveStepsize(x, y + 1)) >= TILEX)
@@ -3894,15 +3703,16 @@ void Impact(int x, int y)
     if (object_hit)
       smashed = MovingOrBlocked2Element(x, y + 1);
 
-    impact = (lastline || object_hit);
+    impact = (last_line || object_hit);
   }
 
-  if (!lastline && smashed == EL_ACID) /* element falls into acid */
+  if (!last_line && smashed == EL_ACID)        /* element falls into acid */
   {
     SplashAcid(x, y + 1);
     return;
   }
 
+  /* !!! not sufficient for all cases -- see EL_PEARL below !!! */
   /* only reset graphic animation if graphic really changes after impact */
   if (impact &&
       el_act_dir2img(element, GfxAction[x][y], MV_DOWN) != el2img(element))
@@ -3918,6 +3728,8 @@ void Impact(int x, int y)
   }
   else if (impact && element == EL_PEARL)
   {
+    ResetGfxAnimation(x, y);
+
     Feld[x][y] = EL_PEARL_BREAKING;
     PlayLevelSound(x, y, SND_PEARL_BREAKING);
     return;
@@ -3932,7 +3744,7 @@ void Impact(int x, int y)
   if (impact && element == EL_AMOEBA_DROP)
   {
     if (object_hit && IS_PLAYER(x, y + 1))
-      KillHeroUnlessEnemyProtected(x, y + 1);
+      KillPlayerUnlessEnemyProtected(x, y + 1);
     else if (object_hit && smashed == EL_PENGUIN)
       Bang(x, y + 1);
     else
@@ -3974,7 +3786,7 @@ void Impact(int x, int y)
     {
       if (CAN_SMASH_PLAYER(element))
       {
-       KillHeroUnlessEnemyProtected(x, y + 1);
+       KillPlayerUnlessEnemyProtected(x, y + 1);
        return;
       }
     }
@@ -4005,13 +3817,6 @@ void Impact(int x, int y)
       Bang(x, y + 1);
       return;
     }
-#if 0
-    else if (CAN_SMASH_ENEMIES(element) && IS_CLASSIC_ENEMY(smashed))
-    {
-      Bang(x, y + 1);
-      return;
-    }
-#endif
     else if (CAN_SMASH_EVERYTHING(element))
     {
       if (IS_CLASSIC_ENEMY(smashed) ||
@@ -4037,6 +3842,8 @@ void Impact(int x, int y)
        }
        else if (smashed == EL_PEARL)
        {
+         ResetGfxAnimation(x, y);
+
          Feld[x][y + 1] = EL_PEARL_BREAKING;
          PlayLevelSound(x, y, SND_PEARL_BREAKING);
          return;
@@ -4069,10 +3876,10 @@ void Impact(int x, int y)
 
          CheckElementChange(x, y + 1, smashed, element, CE_SMASHED);
 
-         CheckTriggeredElementChangeSide(x, y + 1, smashed,
-                                         CE_OTHER_IS_SWITCHING, CH_SIDE_TOP);
-         CheckElementChangeSide(x, y + 1, smashed, element,
-                                CE_SWITCHED, CH_SIDE_TOP);
+         CheckElementChangeBySide(x, y + 1, smashed, element,
+                                  CE_SWITCHED, CH_SIDE_TOP);
+         CheckTriggeredElementChangeBySide(smashed, CE_SWITCH_OF_X,
+                                           CH_SIDE_TOP);
        }
       }
       else
@@ -4083,7 +3890,7 @@ void Impact(int x, int y)
   }
 
   /* play sound of magic wall / mill */
-  if (!lastline &&
+  if (!last_line &&
       (Feld[x][y + 1] == EL_MAGIC_WALL_ACTIVE ||
        Feld[x][y + 1] == EL_BD_MAGIC_WALL_ACTIVE))
   {
@@ -4096,7 +3903,7 @@ void Impact(int x, int y)
   }
 
   /* play sound of object that hits the ground */
-  if (lastline || object_hit)
+  if (last_line || object_hit)
     PlayLevelSoundElementAction(x, y, element, ACTION_IMPACT);
 }
 
@@ -4164,26 +3971,6 @@ inline static void TurnRoundExt(int x, int y)
     else if (element == EL_BD_BUTTERFLY)     /* && MovDir[x][y] == left_dir) */
       MovDelay[x][y] = 1;
   }
-#if 0
-  else if (element == EL_SPACESHIP || element == EL_BD_FIREFLY ||
-          element == EL_SP_SNIKSNAK || element == EL_SP_ELECTRON)
-  {
-    TestIfBadThingTouchesOtherBadThing(x, y);
-
-    if (ENEMY_CAN_ENTER_FIELD(element, left_x, left_y))
-      MovDir[x][y] = left_dir;
-    else if (!ENEMY_CAN_ENTER_FIELD(element, move_x, move_y))
-      MovDir[x][y] = right_dir;
-
-    if ((element == EL_SPACESHIP ||
-        element == EL_SP_SNIKSNAK ||
-        element == EL_SP_ELECTRON)
-       && MovDir[x][y] != old_move_dir)
-      MovDelay[x][y] = 9;
-    else if (element == EL_BD_FIREFLY)     /* && MovDir[x][y] == right_dir) */
-      MovDelay[x][y] = 1;
-  }
-#else
   else if (element == EL_SPACESHIP || element == EL_BD_FIREFLY)
   {
     TestIfBadThingTouchesOtherBadThing(x, y);
@@ -4210,7 +3997,6 @@ inline static void TurnRoundExt(int x, int y)
     if (MovDir[x][y] != old_move_dir)
       MovDelay[x][y] = 9;
   }
-#endif
   else if (element == EL_YAMYAM)
   {
     boolean can_turn_left  = YAMYAM_CAN_ENTER_FIELD(element, left_x, left_y);
@@ -4319,7 +4105,8 @@ inline static void TurnRoundExt(int x, int y)
     xx = x + move_xy[MovDir[x][y]].x;
     yy = y + move_xy[MovDir[x][y]].y;
 
-    if (!IS_FREE(xx, yy) && !IS_FOOD_PIG(Feld[xx][yy]))
+    if (!IN_LEV_FIELD(xx, yy) ||
+        (!IS_FREE(xx, yy) && !IS_FOOD_PIG(Feld[xx][yy])))
       MovDir[x][y] = old_move_dir;
 
     MovDelay[x][y] = 0;
@@ -4332,11 +4119,6 @@ inline static void TurnRoundExt(int x, int y)
     int rnd_value = 24;
     int rnd = RND(rnd_value);
 
-#if 0
-    if (FrameCounter < 1 && x == 0 && y == 29)
-      printf(":2: %d/%d: %d [%d]\n", x, y, MovDir[x][y], FrameCounter);
-#endif
-
     if (can_move_on && rnd > rnd_value / 8)
       MovDir[x][y] = old_move_dir;
     else if (can_turn_left && can_turn_right)
@@ -4351,25 +4133,8 @@ inline static void TurnRoundExt(int x, int y)
     xx = x + move_xy[MovDir[x][y]].x;
     yy = y + move_xy[MovDir[x][y]].y;
 
-#if 0
-    if (FrameCounter < 1 && x == 0 && y == 29)
-      printf(":3: %d/%d: %d (%d/%d: %d) [%d]\n", x, y, MovDir[x][y],
-            xx, yy, Feld[xx][yy],
-            FrameCounter);
-#endif
-
-#if 1
     if (!IN_LEV_FIELD_AND_IS_FREE(xx, yy))
       MovDir[x][y] = old_move_dir;
-#else
-    if (!IS_FREE(xx, yy))
-      MovDir[x][y] = old_move_dir;
-#endif
-
-#if 0
-    if (FrameCounter < 1 && x == 0 && y == 29)
-      printf(":4: %d/%d: %d [%d]\n", x, y, MovDir[x][y], FrameCounter);
-#endif
 
     MovDelay[x][y] = 0;
   }
@@ -4407,16 +4172,10 @@ inline static void TurnRoundExt(int x, int y)
   }
   else if (element == EL_SPRING)
   {
-#if 0
-    if (MovDir[x][y] & MV_HORIZONTAL &&
-       !SPRING_CAN_ENTER_FIELD(element, move_x, move_y))
-      MovDir[x][y] = MV_NO_MOVING;
-#else
     if (MovDir[x][y] & MV_HORIZONTAL &&
        (!SPRING_CAN_ENTER_FIELD(element, move_x, move_y) ||
         SPRING_CAN_ENTER_FIELD(element, x, y + 1)))
       MovDir[x][y] = MV_NO_MOVING;
-#endif
 
     MovDelay[x][y] = 0;
   }
@@ -4452,7 +4211,9 @@ inline static void TurnRoundExt(int x, int y)
       }
     }
 
-    if (element == EL_ROBOT && ZX >= 0 && ZY >= 0)
+    if (element == EL_ROBOT && ZX >= 0 && ZY >= 0 &&
+       (Feld[ZX][ZY] == EL_ROBOT_WHEEL_ACTIVE ||
+        game.engine_version < VERSION_IDENT(3,1,0,0)))
     {
       attr_x = ZX;
       attr_y = ZY;
@@ -4577,6 +4338,9 @@ inline static void TurnRoundExt(int x, int y)
     boolean can_turn_right =
       CUSTOM_ELEMENT_CAN_ENTER_FIELD(element, right_x,right_y);
 
+    if (element_info[element].move_stepsize == 0)      /* "not moving" */
+      return;
+
     if (move_pattern == MV_TURNING_LEFT)
       MovDir[x][y] = left_dir;
     else if (move_pattern == MV_TURNING_RIGHT)
@@ -4687,6 +4451,14 @@ inline static void TurnRoundExt(int x, int y)
       boolean first_horiz = RND(2);
       int new_move_dir = MovDir[x][y];
 
+      if (element_info[element].move_stepsize == 0)    /* "not moving" */
+      {
+       first_horiz = (ABS(attr_x - x) >= ABS(attr_y - y));
+       MovDir[x][y] &= (first_horiz ? MV_HORIZONTAL : MV_VERTICAL);
+
+       return;
+      }
+
       MovDir[x][y] =
        new_move_dir & (first_horiz ? MV_HORIZONTAL : MV_VERTICAL);
       Moving2Blocked(x, y, &newx, &newy);
@@ -4780,7 +4552,7 @@ inline static void TurnRoundExt(int x, int y)
 
     MovDir[x][y] = new_move_dir;
     if (old_move_dir != new_move_dir)
-      MovDelay[x][y] = 9;
+      MovDelay[x][y] = GET_NEW_MOVE_DELAY(element);
   }
 }
 
@@ -4788,26 +4560,15 @@ static void TurnRound(int x, int y)
 {
   int direction = MovDir[x][y];
 
-#if 0
-  GfxDir[x][y] = MovDir[x][y];
-#endif
-
   TurnRoundExt(x, y);
 
-#if 1
   GfxDir[x][y] = MovDir[x][y];
-#endif
 
   if (direction != MovDir[x][y])
     GfxFrame[x][y] = 0;
 
-#if 1
   if (MovDelay[x][y])
     GfxAction[x][y] = ACTION_TURNING_FROM_LEFT + MV_DIR_BIT(direction);
-#else
-  if (MovDelay[x][y])
-    GfxAction[x][y] = ACTION_WAITING;
-#endif
 }
 
 static boolean JustBeingPushed(int x, int y)
@@ -4833,23 +4594,14 @@ static boolean JustBeingPushed(int x, int y)
 
 void StartMoving(int x, int y)
 {
-#if 0
-  boolean use_spring_bug = (game.engine_version < VERSION_IDENT(2,2,0,0));
-#endif
   boolean started_moving = FALSE;      /* some elements can fall _and_ move */
   int element = Feld[x][y];
 
   if (Stop[x][y])
     return;
 
-#if 1
   if (MovDelay[x][y] == 0)
     GfxAction[x][y] = ACTION_DEFAULT;
-#else
-  /* !!! this should be handled more generic (not only for mole) !!! */
-  if (element != EL_MOLE && GfxAction[x][y] != ACTION_DIGGING)
-    GfxAction[x][y] = ACTION_DEFAULT;
-#endif
 
   if (CAN_FALL(element) && y < lev_fieldy - 1)
   {
@@ -4867,11 +4619,8 @@ void StartMoving(int x, int y)
 
        Feld[x][y] = EL_QUICKSAND_EMPTYING;
        Store[x][y] = EL_ROCK;
-#if 1
+
        PlayLevelSoundAction(x, y, ACTION_EMPTYING);
-#else
-       PlayLevelSound(x, y, SND_QUICKSAND_EMPTYING);
-#endif
       }
       else if (Feld[x][y + 1] == EL_QUICKSAND_EMPTY)
       {
@@ -4889,11 +4638,8 @@ void StartMoving(int x, int y)
        Feld[x][y + 1] = EL_QUICKSAND_FULL;
        Store[x][y + 1] = Store[x][y];
        Store[x][y] = 0;
-#if 1
+
        PlayLevelSoundAction(x, y, ACTION_FILLING);
-#else
-       PlayLevelSound(x, y, SND_QUICKSAND_FILLING);
-#endif
       }
     }
     else if ((element == EL_ROCK || element == EL_BD_ROCK) &&
@@ -4904,11 +4650,8 @@ void StartMoving(int x, int y)
 
       Feld[x][y] = EL_QUICKSAND_FILLING;
       Store[x][y] = element;
-#if 1
+
       PlayLevelSoundAction(x, y, ACTION_FILLING);
-#else
-      PlayLevelSound(x, y, SND_QUICKSAND_FILLING);
-#endif
     }
     else if (element == EL_MAGIC_WALL_FULL)
     {
@@ -4978,11 +4721,7 @@ void StartMoving(int x, int y)
         EL_BD_MAGIC_WALL_FILLING);
       Store[x][y] = element;
     }
-#if 0
-    else if (CAN_SMASH(element) && Feld[x][y + 1] == EL_ACID)
-#else
     else if (CAN_FALL(element) && Feld[x][y + 1] == EL_ACID)
-#endif
     {
       SplashAcid(x, y + 1);
 
@@ -4990,30 +4729,17 @@ void StartMoving(int x, int y)
       started_moving = TRUE;
 
       Store[x][y] = EL_ACID;
-#if 0
-      /* !!! TEST !!! better use "_FALLING" etc. !!! */
-      GfxAction[x][y + 1] = ACTION_ACTIVE;
-#endif
     }
-#if 1
-    else if ((game.engine_version < VERSION_IDENT(2,2,0,7) &&
-             CAN_SMASH(element) && WasJustMoving[x][y] && !Pushed[x][y + 1] &&
-             (Feld[x][y + 1] == EL_BLOCKED)) ||
-            (game.engine_version >= VERSION_IDENT(3,0,7,0) &&
-             CAN_SMASH(element) && WasJustFalling[x][y] &&
-             (Feld[x][y + 1] == EL_BLOCKED || IS_PLAYER(x, y + 1))))
+    else if ((game.engine_version >= VERSION_IDENT(3,1,0,0) &&
+             CheckCollision[x][y] && !IS_FREE(x, y + 1)) ||
 
-#else
-#if 1
-    else if (game.engine_version < VERSION_IDENT(2,2,0,7) &&
-            CAN_SMASH(element) && Feld[x][y + 1] == EL_BLOCKED &&
-            WasJustMoving[x][y] && !Pushed[x][y + 1])
-#else
-    else if (CAN_SMASH(element) && Feld[x][y + 1] == EL_BLOCKED &&
-            WasJustMoving[x][y])
-#endif
-#endif
+            (game.engine_version >= VERSION_IDENT(3,0,7,0) &&
+             CAN_FALL(element) && WasJustFalling[x][y] &&
+             (Feld[x][y + 1] == EL_BLOCKED || IS_PLAYER(x, y + 1))) ||
 
+            (game.engine_version < VERSION_IDENT(2,2,0,7) &&
+             CAN_FALL(element) && WasJustMoving[x][y] && !Pushed[x][y + 1] &&
+             (Feld[x][y + 1] == EL_BLOCKED)))
     {
       /* this is needed for a special case not covered by calling "Impact()"
         from "ContinueMoving()": if an element moves to a tile directly below
@@ -5025,10 +4751,7 @@ void StartMoving(int x, int y)
         element; also, the case of the player being the element to smash was
         simply not covered here... :-/ ) */
 
-#if 0
-      WasJustMoving[x][y] = 0;
-      WasJustFalling[x][y] = 0;
-#endif
+      CheckCollision[x][y] = 0;
 
       Impact(x, y);
     }
@@ -5053,23 +4776,10 @@ void StartMoving(int x, int y)
       Feld[x][y] = EL_AMOEBA_GROWING;
       Store[x][y] = EL_AMOEBA_WET;
     }
-    /* Store[x][y + 1] must be zero, because:
-       (EL_QUICKSAND_FULL -> EL_ROCK): Store[x][y + 1] == EL_QUICKSAND_EMPTY
-    */
-#if 0
-#if OLD_GAME_BEHAVIOUR
-    else if (IS_SLIPPERY(Feld[x][y + 1]) && !Store[x][y + 1])
-#else
-    else if (IS_SLIPPERY(Feld[x][y + 1]) && !Store[x][y + 1] &&
-            !IS_FALLING(x, y + 1) && !WasJustMoving[x][y + 1] &&
-            element != EL_DX_SUPABOMB)
-#endif
-#else
     else if (((IS_SLIPPERY(Feld[x][y + 1]) && !IS_PLAYER(x, y + 1)) ||
              (IS_EM_SLIPPERY_WALL(Feld[x][y + 1]) && IS_GEM(element))) &&
             !IS_FALLING(x, y + 1) && !WasJustMoving[x][y + 1] &&
             element != EL_DX_SUPABOMB && element != EL_SP_DISK_ORANGE)
-#endif
     {
       boolean can_fall_left  = (x > 0 && IS_FREE(x - 1, y) &&
                                (IS_FREE(x - 1, y + 1) ||
@@ -5079,11 +4789,26 @@ void StartMoving(int x, int y)
                                 Feld[x + 1][y + 1] == EL_ACID));
       boolean can_fall_any  = (can_fall_left || can_fall_right);
       boolean can_fall_both = (can_fall_left && can_fall_right);
+      int slippery_type = element_info[Feld[x][y + 1]].slippery_type;
 
-      if (can_fall_any && IS_CUSTOM_ELEMENT(Feld[x][y + 1]))
+#if USE_NEW_ALL_SLIPPERY
+      if (can_fall_any && slippery_type != SLIPPERY_ANY_RANDOM)
       {
-       int slippery_type = element_info[Feld[x][y + 1]].slippery_type;
+       if (slippery_type == SLIPPERY_ANY_LEFT_RIGHT && can_fall_both)
+         can_fall_right = FALSE;
+       else if (slippery_type == SLIPPERY_ANY_RIGHT_LEFT && can_fall_both)
+         can_fall_left = FALSE;
+       else if (slippery_type == SLIPPERY_ONLY_LEFT)
+         can_fall_right = FALSE;
+       else if (slippery_type == SLIPPERY_ONLY_RIGHT)
+         can_fall_left = FALSE;
 
+       can_fall_any  = (can_fall_left || can_fall_right);
+       can_fall_both = FALSE;
+      }
+#else
+      if (can_fall_any && IS_CUSTOM_ELEMENT(Feld[x][y + 1]))
+      {
        if (slippery_type == SLIPPERY_ONLY_LEFT)
          can_fall_right = FALSE;
        else if (slippery_type == SLIPPERY_ONLY_RIGHT)
@@ -5096,14 +4821,47 @@ void StartMoving(int x, int y)
        can_fall_any  = (can_fall_left || can_fall_right);
        can_fall_both = (can_fall_left && can_fall_right);
       }
+#endif
 
-      if (can_fall_any)
+#if USE_NEW_ALL_SLIPPERY
+#else
+#if USE_NEW_SP_SLIPPERY
+      /* !!! better use the same properties as for custom elements here !!! */
+      else if (game.engine_version >= VERSION_IDENT(3,1,1,0) &&
+              can_fall_both && IS_SP_ELEMENT(Feld[x][y + 1]))
+      {
+       can_fall_right = FALSE;         /* slip down on left side */
+       can_fall_both = FALSE;
+      }
+#endif
+#endif
+
+#if USE_NEW_ALL_SLIPPERY
+      if (can_fall_both)
+      {
+       if (element == EL_BD_ROCK || element == EL_BD_DIAMOND)
+         can_fall_right = FALSE;       /* slip down on left side */
+       else
+         can_fall_left = !(can_fall_right = RND(2));
+
+       can_fall_both = FALSE;
+      }
+#else
+      if (can_fall_both)
       {
-       if (can_fall_both &&
-           (game.emulation != EMU_BOULDERDASH &&
-            element != EL_BD_ROCK && element != EL_BD_DIAMOND))
+       if (game.emulation == EMU_BOULDERDASH ||
+           element == EL_BD_ROCK || element == EL_BD_DIAMOND)
+         can_fall_right = FALSE;       /* slip down on left side */
+       else
          can_fall_left = !(can_fall_right = RND(2));
 
+       can_fall_both = FALSE;
+      }
+#endif
+
+      if (can_fall_any)
+      {
+       /* if not determined otherwise, prefer left side for slipping down */
        InitMovingField(x, y, can_fall_left ? MV_LEFT : MV_RIGHT);
        started_moving = TRUE;
       }
@@ -5122,17 +4880,13 @@ void StartMoving(int x, int y)
       if ((belt_dir == MV_LEFT  && left_is_free) ||
          (belt_dir == MV_RIGHT && right_is_free))
       {
-#if 1
        int nextx = (belt_dir == MV_LEFT ? x - 1 : x + 1);
-#endif
 
        InitMovingField(x, y, belt_dir);
        started_moving = TRUE;
 
-#if 1
        Pushed[x][y] = TRUE;
        Pushed[nextx][y] = TRUE;
-#endif
 
        GfxAction[x][y] = ACTION_DEFAULT;
       }
@@ -5144,79 +4898,42 @@ void StartMoving(int x, int y)
   }
 
   /* not "else if" because of elements that can fall and move (EL_SPRING) */
+#if 0
+  if (CAN_MOVE(element) && !started_moving && MovDir[x][y] != MV_NO_MOVING)
+#else
   if (CAN_MOVE(element) && !started_moving)
+#endif
   {
     int move_pattern = element_info[element].move_pattern;
     int newx, newy;
 
+#if 0
+#if DEBUG
+    if (MovDir[x][y] == MV_NO_MOVING)
+    {
+      printf("StartMoving(): %d,%d: element %d ['%s'] not moving\n",
+            x, y, element, element_info[element].token_name);
+      printf("StartMoving(): This should never happen!\n");
+    }
+#endif
+#endif
+
     Moving2Blocked(x, y, &newx, &newy);
 
-#if 1
     if (IS_PUSHABLE(element) && JustBeingPushed(x, y))
       return;
-#else
-    if ((element == EL_SATELLITE ||
-        element == EL_BALLOON ||
-        element == EL_SPRING)
-       && JustBeingPushed(x, y))
-      return;
-#endif
 
-#if 1
     if (game.engine_version >= VERSION_IDENT(3,1,0,0) &&
-       WasJustMoving[x][y] && IN_LEV_FIELD(newx, newy) &&
-       (Feld[newx][newy] == EL_BLOCKED || IS_PLAYER(newx, newy)))
+       CheckCollision[x][y] && !IN_LEV_FIELD_AND_IS_FREE(newx, newy))
     {
-#if 0
-      printf("::: element %d '%s' WasJustMoving %d [%d, %d, %d, %d]\n",
-            element, element_info[element].token_name,
-            WasJustMoving[x][y],
-            HAS_ANY_CHANGE_EVENT(element, CE_HITTING_SOMETHING),
-            HAS_ANY_CHANGE_EVENT(element, CE_HIT_BY_SOMETHING),
-            HAS_ANY_CHANGE_EVENT(element, CE_OTHER_IS_HITTING),
-            HAS_ANY_CHANGE_EVENT(element, CE_OTHER_GETS_HIT));
-#endif
-
-#if 1
       WasJustMoving[x][y] = 0;
-#endif
+      CheckCollision[x][y] = 0;
 
       TestIfElementHitsCustomElement(x, y, MovDir[x][y]);
 
-#if 0
-      if (Feld[x][y] != element)       /* element has changed */
-      {
-       element = Feld[x][y];
-       move_pattern = element_info[element].move_pattern;
-
-       if (!CAN_MOVE(element))
-         return;
-      }
-#else
       if (Feld[x][y] != element)       /* element has changed */
        return;
-#endif
-    }
-#endif
-
-#if 0
-#if 0
-    if (element == EL_SPRING && MovDir[x][y] == MV_DOWN)
-      Feld[x][y + 1] = EL_EMPTY;       /* was set to EL_BLOCKED above */
-#else
-    if (element == EL_SPRING && MovDir[x][y] != MV_NO_MOVING)
-    {
-      Moving2Blocked(x, y, &newx, &newy);
-      if (Feld[newx][newy] == EL_BLOCKED)
-       Feld[newx][newy] = EL_EMPTY;    /* was set to EL_BLOCKED above */
     }
-#endif
-#endif
-
-#if 0
-    if (FrameCounter < 1 && x == 0 && y == 29)
-      printf(":1: %d/%d: %d [%d]\n", x, y, MovDir[x][y], FrameCounter);
-#endif
 
     if (!MovDelay[x][y])       /* start new movement phase */
     {
@@ -5235,11 +4952,6 @@ void StartMoving(int x, int y)
       {
        TurnRound(x, y);
 
-#if 0
-       if (FrameCounter < 1 && x == 0 && y == 29)
-         printf(":9: %d: %d [%d]\n", y, MovDir[x][y], FrameCounter);
-#endif
-
        if (MovDelay[x][y] && (element == EL_BUG ||
                               element == EL_SPACESHIP ||
                               element == EL_SP_SNIKSNAK ||
@@ -5253,42 +4965,11 @@ void StartMoving(int x, int y)
     {
       MovDelay[x][y]--;
 
-#if 0
-      if (element == EL_YAMYAM)
-      {
-       printf("::: %d\n",
-              el_act_dir2img(EL_YAMYAM, ACTION_WAITING, MV_LEFT));
-       DrawLevelElementAnimation(x, y, element);
-      }
-#endif
-
-      if (MovDelay[x][y])      /* element still has to wait some time */
-      {
-#if 0
-       /* !!! PLACE THIS SOMEWHERE AFTER "TurnRound()" !!! */
-       ResetGfxAnimation(x, y);
-#endif
-
-#if 0
-       if (GfxAction[x][y] != ACTION_WAITING)
-         printf("::: %d: %d != ACTION_WAITING\n", element, GfxAction[x][y]);
-
-       GfxAction[x][y] = ACTION_WAITING;
-#endif
-      }
-
       if (element == EL_ROBOT ||
-#if 0
-         element == EL_PACMAN ||
-#endif
          element == EL_YAMYAM ||
          element == EL_DARK_YAMYAM)
       {
-#if 0
-       DrawLevelElementAnimation(x, y, element);
-#else
        DrawLevelElementAnimationIfNeeded(x, y, element);
-#endif
        PlayLevelSoundAction(x, y, ACTION_WAITING);
       }
       else if (element == EL_SP_ELECTRON)
@@ -5305,10 +4986,6 @@ void StartMoving(int x, int y)
                       dir == MV_DOWN   ? IMG_FLAMES_1_DOWN : IMG_EMPTY);
        int frame = getGraphicAnimationFrame(graphic, GfxFrame[x][y]);
 
-#if 0
-       printf("::: %d, %d\n", GfxAction[x][y], GfxFrame[x][y]);
-#endif
-
        GfxAction[x][y] = ACTION_ATTACKING;
 
        if (IS_PLAYER(x, y))
@@ -5333,12 +5010,25 @@ void StartMoving(int x, int y)
          {
            int flamed = MovingOrBlocked2Element(xx, yy);
 
+           /* !!! */
+#if 0
+           if (IS_CLASSIC_ENEMY(flamed) || CAN_EXPLODE_BY_DRAGONFIRE(flamed))
+             Bang(xx, yy);
+           else if (IS_MOVING(xx, yy) || IS_BLOCKED(xx, yy))
+             RemoveMovingField(xx, yy);
+           else
+             RemoveField(xx, yy);
+#else
            if (IS_CLASSIC_ENEMY(flamed) || CAN_EXPLODE_BY_DRAGONFIRE(flamed))
              Bang(xx, yy);
            else
              RemoveMovingField(xx, yy);
+#endif
+
+           ChangeDelay[xx][yy] = 0;
 
            Feld[xx][yy] = EL_FLAMES;
+
            if (IN_SCR_FIELD(sx, sy))
            {
              DrawLevelFieldCrumbledSand(xx, yy);
@@ -5360,13 +5050,6 @@ void StartMoving(int x, int y)
 
        return;
       }
-
-#if 0
-      /* special case of "moving" animation of waiting elements (FIX THIS !!!);
-        for all other elements GfxAction will be set by InitMovingField() */
-      if (element == EL_BD_BUTTERFLY || element == EL_BD_FIREFLY)
-       GfxAction[x][y] = ACTION_MOVING;
-#endif
     }
 
     /* now make next step */
@@ -5377,38 +5060,15 @@ void StartMoving(int x, int y)
        IN_LEV_FIELD(newx, newy) && IS_PLAYER(newx, newy) &&
        !PLAYER_ENEMY_PROTECTED(newx, newy))
     {
-#if 1
-      TestIfBadThingRunsIntoHero(x, y, MovDir[x][y]);
+      TestIfBadThingRunsIntoPlayer(x, y, MovDir[x][y]);
 
       return;
-#else
-      /* player killed by element which is deadly when colliding with */
-      MovDir[x][y] = 0;
-      KillHero(PLAYERINFO(newx, newy));
-      return;
-#endif
-
     }
-#if 1
-#if 1
+
     else if (CAN_MOVE_INTO_ACID(element) &&
             IN_LEV_FIELD(newx, newy) && Feld[newx][newy] == EL_ACID &&
             (MovDir[x][y] == MV_DOWN ||
              game.engine_version >= VERSION_IDENT(3,1,0,0)))
-#else
-    else if (CAN_MOVE_INTO_ACID(element) && MovDir[x][y] == MV_DOWN &&
-            IN_LEV_FIELD(newx, newy) && Feld[newx][newy] == EL_ACID)
-#endif
-#else
-
-    else if ((element == EL_PENGUIN ||
-             element == EL_ROBOT ||
-             element == EL_SATELLITE ||
-             element == EL_BALLOON ||
-             IS_CUSTOM_ELEMENT(element)) &&
-            IN_LEV_FIELD(newx, newy) &&
-            MovDir[x][y] == MV_DOWN && Feld[newx][newy] == EL_ACID)
-#endif
     {
       SplashAcid(newx, newy);
       Store[x][y] = EL_ACID;
@@ -5417,13 +5077,8 @@ void StartMoving(int x, int y)
     {
       if (Feld[newx][newy] == EL_EXIT_OPEN)
       {
-#if 1
        RemoveField(x, y);
        DrawLevelField(x, y);
-#else
-       Feld[x][y] = EL_EMPTY;
-       DrawLevelField(x, y);
-#endif
 
        PlayLevelSound(newx, newy, SND_PENGUIN_PASSING);
        if (IN_SCR_FIELD(SCREENX(newx), SCREENY(newy)))
@@ -5479,32 +5134,11 @@ void StartMoving(int x, int y)
        return;
       }
     }
-
-#if 1
-
-    /*
-    else if (move_pattern & MV_MAZE_RUNNER_STYLE && IN_LEV_FIELD(newx, newy))
-    */
-
     else if (IS_CUSTOM_ELEMENT(element) &&
-            CUSTOM_ELEMENT_CAN_ENTER_FIELD(element, newx, newy)
-
-#if 0
- &&
-            !IS_FREE(newx, newy)
-#endif
-
-)
+            CUSTOM_ELEMENT_CAN_ENTER_FIELD(element, newx, newy))
     {
       int new_element = Feld[newx][newy];
 
-#if 0
-      printf("::: '%s' digs '%s' [%d]\n",
-            element_info[element].token_name,
-            element_info[Feld[newx][newy]].token_name,
-            StorePlayer[newx][newy]);
-#endif
-
       if (!IS_FREE(newx, newy))
       {
        int action = (IS_DIGGABLE(new_element) ? ACTION_DIGGING :
@@ -5534,11 +5168,21 @@ void StartMoving(int x, int y)
          DrawLevelField(newx, newy);
        }
 
+       /* if digged element was about to explode, prevent the explosion */
+       ExplodeField[newx][newy] = EX_TYPE_NONE;
+
        PlayLevelSoundAction(x, y, action);
       }
 
+      Store[newx][newy] = EL_EMPTY;
       if (IS_EQUAL_OR_IN_GROUP(new_element, MOVE_ENTER_EL(element)))
-       element_info[element].can_leave_element = TRUE;
+      {
+       int move_leave_element = element_info[element].move_leave_element;
+
+       /* this makes it possible to leave the removed element again */
+       Store[newx][newy] = (move_leave_element == EL_TRIGGER_ELEMENT ?
+                            new_element : move_leave_element);
+      }
 
       if (move_pattern & MV_MAZE_RUNNER_STYLE)
       {
@@ -5546,9 +5190,6 @@ void StartMoving(int x, int y)
        PlayerVisit[x][y] /= 8;         /* expire player visit path */
       }
     }
-
-#endif
-
     else if (element == EL_DRAGON && IN_LEV_FIELD(newx, newy))
     {
       if (!IS_FREE(newx, newy))
@@ -5577,10 +5218,8 @@ void StartMoving(int x, int y)
            element1 != EL_DRAGON && element2 != EL_DRAGON &&
            element1 != EL_FLAMES && element2 != EL_FLAMES)
        {
-#if 1
          ResetGfxAnimation(x, y);
          GfxAction[x][y] = ACTION_ATTACKING;
-#endif
 
          if (IS_PLAYER(x, y))
            DrawPlayerField(x, y);
@@ -5591,11 +5230,25 @@ void StartMoving(int x, int y)
 
          MovDelay[x][y] = 50;
 
+         /* !!! */
+#if 0
+         RemoveField(newx, newy);
+#endif
          Feld[newx][newy] = EL_FLAMES;
          if (IN_LEV_FIELD(newx1, newy1) && Feld[newx1][newy1] == EL_EMPTY)
+         {
+#if 0
+           RemoveField(newx1, newy1);
+#endif
            Feld[newx1][newy1] = EL_FLAMES;
+         }
          if (IN_LEV_FIELD(newx2, newy2) && Feld[newx2][newy2] == EL_EMPTY)
+         {
+#if 0
+           RemoveField(newx2, newy2);
+#endif
            Feld[newx2][newy2] = EL_FLAMES;
+         }
 
          return;
        }
@@ -5628,12 +5281,15 @@ void StartMoving(int x, int y)
 #if 0
       /* !!! test !!! */
       if (IS_MOVING(newx, newy) || IS_BLOCKED(newx, newy))
+      {
+       RemoveMovingField(newx, newy);
+      }
 #else
       if (IS_MOVING(newx, newy))
-#endif
       {
        RemoveMovingField(newx, newy);
       }
+#endif
       else
       {
        Feld[newx][newy] = EL_EMPTY;
@@ -5686,31 +5342,26 @@ void StartMoving(int x, int y)
 
       TurnRound(x, y);
 
-#if 1
+#if 0
+      /* !!! NEW "CE_BLOCKED" STUFF !!! -- DOES NOT WORK YET... !!! */
+      if (move_pattern & MV_ANY_DIRECTION &&
+         move_pattern == MovDir[x][y])
+      {
+       int blocking_element =
+         (IN_LEV_FIELD(newx, newy) ? Feld[newx][newy] : BorderElement);
+
+       CheckElementChangeBySide(x, y, element, blocking_element, CE_BLOCKED,
+                                MovDir[x][y]);
+
+       element = Feld[x][y];   /* element might have changed */
+      }
+#endif
+
       if (GFX_ELEMENT(element) != EL_SAND)     /* !!! FIX THIS (crumble) !!! */
        DrawLevelElementAnimation(x, y, element);
-#else
-      if (element == EL_BUG ||
-         element == EL_SPACESHIP ||
-         element == EL_SP_SNIKSNAK)
-       DrawLevelField(x, y);
-      else if (element == EL_MOLE)
-       DrawLevelField(x, y);
-      else if (element == EL_BD_BUTTERFLY ||
-              element == EL_BD_FIREFLY)
-       DrawLevelElementAnimationIfNeeded(x, y, element);
-      else if (element == EL_SATELLITE)
-       DrawLevelElementAnimationIfNeeded(x, y, element);
-      else if (element == EL_SP_ELECTRON)
-       DrawLevelElementAnimationIfNeeded(x, y, element);
-#endif
 
       if (DONT_TOUCH(element))
-       TestIfBadThingTouchesHero(x, y);
-
-#if 0
-      PlayLevelSoundAction(x, y, ACTION_WAITING);
-#endif
+       TestIfBadThingTouchesPlayer(x, y);
 
       return;
     }
@@ -5727,33 +5378,20 @@ void StartMoving(int x, int y)
 void ContinueMoving(int x, int y)
 {
   int element = Feld[x][y];
+  int stored = Store[x][y];
   struct ElementInfo *ei = &element_info[element];
   int direction = MovDir[x][y];
   int dx = (direction == MV_LEFT ? -1 : direction == MV_RIGHT ? +1 : 0);
   int dy = (direction == MV_UP   ? -1 : direction == MV_DOWN  ? +1 : 0);
   int newx = x + dx, newy = y + dy;
-#if 0
-  int nextx = newx + dx, nexty = newy + dy;
-#endif
-#if 1
   boolean pushed_by_player   = (Pushed[x][y] && IS_PLAYER(x, y));
   boolean pushed_by_conveyor = (Pushed[x][y] && !IS_PLAYER(x, y));
-#else
-  boolean pushed_by_player = Pushed[x][y];
-#endif
+  boolean last_line = (newy == lev_fieldy - 1);
 
   MovPos[x][y] += getElementMoveStepsize(x, y);
 
-#if 0
-  if (pushed_by_player && IS_PLAYER(x, y))
-  {
-    /* special case: moving object pushed by player */
-    MovPos[x][y] = SIGN(MovPos[x][y]) * (TILEX - ABS(PLAYERINFO(x,y)->MovPos));
-  }
-#else
   if (pushed_by_player)        /* special case: moving object pushed by player */
     MovPos[x][y] = SIGN(MovPos[x][y]) * (TILEX - ABS(PLAYERINFO(x,y)->MovPos));
-#endif
 
   if (ABS(MovPos[x][y]) < TILEX)
   {
@@ -5768,7 +5406,11 @@ void ContinueMoving(int x, int y)
   Feld[newx][newy] = element;
   MovPos[x][y] = 0;    /* force "not moving" for "crumbled sand" */
 
-  if (element == EL_MOLE)
+  if (Store[x][y] == EL_ACID)  /* element is moving into acid pool */
+  {
+    element = Feld[newx][newy] = EL_ACID;
+  }
+  else if (element == EL_MOLE)
   {
     Feld[x][y] = EL_SAND;
 
@@ -5797,6 +5439,10 @@ void ContinueMoving(int x, int y)
     if (!game.magic_wall_active)
       Feld[x][y] = EL_MAGIC_WALL_DEAD;
     element = Feld[newx][newy] = Store[x][y];
+
+#if USE_NEW_COLLECT_COUNT
+    InitField(newx, newy, FALSE);
+#endif
   }
   else if (element == EL_BD_MAGIC_WALL_FILLING)
   {
@@ -5811,6 +5457,10 @@ void ContinueMoving(int x, int y)
     if (!game.magic_wall_active)
       Feld[x][y] = EL_BD_MAGIC_WALL_DEAD;
     element = Feld[newx][newy] = Store[x][y];
+
+#if USE_NEW_COLLECT_COUNT
+    InitField(newx, newy, FALSE);
+#endif
   }
   else if (element == EL_AMOEBA_DROPPING)
   {
@@ -5827,13 +5477,12 @@ void ContinueMoving(int x, int y)
 
     Back[x][y] = Back[newx][newy] = 0;
   }
-  else if (Store[x][y] == EL_ACID)
-  {
-    element = Feld[newx][newy] = EL_ACID;
-  }
 
-  Store[x][y] = 0;
-  MovPos[x][y] = MovDir[x][y] = MovDelay[x][y] = 0;
+  Store[x][y] = EL_EMPTY;
+  MovPos[x][y] = 0;
+  MovDir[x][y] = 0;
+  MovDelay[x][y] = 0;
+
   MovDelay[newx][newy] = 0;
 
   if (CAN_CHANGE(element))
@@ -5843,12 +5492,20 @@ void ContinueMoving(int x, int y)
     ChangePage[newx][newy]  = ChangePage[x][y];
     Changed[newx][newy]     = Changed[x][y];
     ChangeEvent[newx][newy] = ChangeEvent[x][y];
+
+#if USE_NEW_COLLECT_COUNT
+    Count[newx][newy] = Count[x][y];
+#endif
   }
 
   ChangeDelay[x][y] = 0;
   ChangePage[x][y] = -1;
-  Changed[x][y] = CE_BITMASK_DEFAULT;
-  ChangeEvent[x][y] = CE_BITMASK_DEFAULT;
+  Changed[x][y] = FALSE;
+  ChangeEvent[x][y] = -1;
+
+#if USE_NEW_COLLECT_COUNT
+  Count[x][y] = 0;
+#endif
 
   /* copy animation control values to new field */
   GfxFrame[newx][newy]  = GfxFrame[x][y];
@@ -5858,50 +5515,42 @@ void ContinueMoving(int x, int y)
 
   Pushed[x][y] = Pushed[newx][newy] = FALSE;
 
-  ResetGfxAnimation(x, y);     /* reset animation values for old field */
-
-#if 1
   /* some elements can leave other elements behind after moving */
-  if (IS_CUSTOM_ELEMENT(element) && !IS_PLAYER(x, y) &&
-      ei->move_leave_element != EL_EMPTY &&
-      (ei->move_leave_type == LEAVE_TYPE_UNLIMITED ||
-       ei->can_leave_element_last))
+  if (IS_CUSTOM_ELEMENT(element) && ei->move_leave_element != EL_EMPTY &&
+      (ei->move_leave_type == LEAVE_TYPE_UNLIMITED || stored != EL_EMPTY) &&
+      (!IS_PLAYER(x, y) || IS_WALKABLE(ei->move_leave_element)))
   {
-    Feld[x][y] = ei->move_leave_element;
+    int move_leave_element = ei->move_leave_element;
+
+    /* this makes it possible to leave the removed element again */
+    if (ei->move_leave_type == LEAVE_TYPE_LIMITED &&
+        ei->move_leave_element == EL_TRIGGER_ELEMENT)
+      move_leave_element = stored;
+
+    Feld[x][y] = move_leave_element;
+
+    if (element_info[Feld[x][y]].move_direction_initial == MV_START_PREVIOUS)
+      MovDir[x][y] = direction;
+
     InitField(x, y, FALSE);
 
     if (GFX_CRUMBLED(Feld[x][y]))
       DrawLevelFieldCrumbledSandNeighbours(x, y);
-  }
-
-  ei->can_leave_element_last = ei->can_leave_element;
-  ei->can_leave_element = FALSE;
-#endif
 
-#if 0
-  /* 2.1.1 (does not work correctly for spring) */
-  if (!CAN_MOVE(element))
-    MovDir[newx][newy] = 0;
-#else
+    if (ELEM_IS_PLAYER(move_leave_element))
+      RelocatePlayer(x, y, move_leave_element);
+  }
 
-#if 0
-  /* (does not work for falling objects that slide horizontally) */
-  if (CAN_FALL(element) && MovDir[newx][newy] == MV_DOWN)
-    MovDir[newx][newy] = 0;
-#else
-  /*
-  if (!CAN_MOVE(element) ||
-      (element == EL_SPRING && MovDir[newx][newy] == MV_DOWN))
-    MovDir[newx][newy] = 0;
-  */
+  /* do this after checking for left-behind element */
+  ResetGfxAnimation(x, y);     /* reset animation values for old field */
 
   if (!CAN_MOVE(element) ||
-      (CAN_FALL(element) && direction == MV_DOWN))
+      (CAN_FALL(element) && direction == MV_DOWN &&
+       (element == EL_SPRING ||
+       element_info[element].move_pattern == MV_WHEN_PUSHED ||
+       element_info[element].move_pattern == MV_WHEN_DROPPED)))
     GfxDir[x][y] = MovDir[newx][newy] = 0;
 
-#endif
-#endif
-
   DrawLevelField(x, y);
   DrawLevelField(newx, newy);
 
@@ -5913,24 +5562,28 @@ void ContinueMoving(int x, int y)
       !(element_info[element].move_pattern & direction))
     TurnRound(newx, newy);
 
-#if 1
   /* prevent elements on conveyor belt from moving on in last direction */
   if (pushed_by_conveyor && CAN_FALL(element) &&
       direction & MV_HORIZONTAL)
     MovDir[newx][newy] = 0;
-#endif
 
   if (!pushed_by_player)
   {
+    int nextx = newx + dx, nexty = newy + dy;
+    boolean check_collision_again = IN_LEV_FIELD_AND_IS_FREE(nextx, nexty);
+
     WasJustMoving[newx][newy] = 3;
 
     if (CAN_FALL(element) && direction == MV_DOWN)
       WasJustFalling[newx][newy] = 3;
+
+    if ((!CAN_FALL(element) || direction == MV_DOWN) && check_collision_again)
+      CheckCollision[newx][newy] = 2;
   }
 
   if (DONT_TOUCH(element))     /* object may be nasty to player or others */
   {
-    TestIfBadThingTouchesHero(newx, newy);
+    TestIfBadThingTouchesPlayer(newx, newy);
     TestIfBadThingTouchesFriend(newx, newy);
 
     if (!IS_CUSTOM_ELEMENT(element))
@@ -5939,96 +5592,27 @@ void ContinueMoving(int x, int y)
   else if (element == EL_PENGUIN)
     TestIfFriendTouchesBadThing(newx, newy);
 
+  /* give the player one last chance (one more frame) to move away */
   if (CAN_FALL(element) && direction == MV_DOWN &&
-      (newy == lev_fieldy - 1 || !IS_FREE(x, newy + 1)))
+      (last_line || (!IS_FREE(x, newy + 1) &&
+                    (!IS_PLAYER(x, newy + 1) ||
+                     game.engine_version < VERSION_IDENT(3,1,1,0)))))
     Impact(x, newy);
 
-#if 1
-  TestIfElementTouchesCustomElement(x, y);     /* empty or new element */
-#endif
-
-#if 0
-  if (ChangePage[newx][newy] != -1)                    /* delayed change */
-    ChangeElement(newx, newy, ChangePage[newx][newy]);
-#endif
-
-#if 1
-
-  TestIfElementHitsCustomElement(newx, newy, direction);
-
-#else
-
-  if (!IN_LEV_FIELD(nextx, nexty) || !IS_FREE(nextx, nexty))
+  if (pushed_by_player && !game.use_change_when_pushing_bug)
   {
-    int hitting_element = Feld[newx][newy];
-
-    /* !!! fix side (direction) orientation here and elsewhere !!! */
-    CheckElementChangeSide(newx, newy, hitting_element, CE_HITTING_SOMETHING,
-                          direction);
-
-#if 0
-    if (IN_LEV_FIELD(nextx, nexty))
-    {
-      int opposite_direction = MV_DIR_OPPOSITE(direction);
-      int hitting_side = direction;
-      int touched_side = opposite_direction;
-      int touched_element = MovingOrBlocked2Element(nextx, nexty);
-      boolean object_hit = (!IS_MOVING(nextx, nexty) ||
-                           MovDir[nextx][nexty] != direction ||
-                           ABS(MovPos[nextx][nexty]) <= TILEY / 2);
-
-      if (object_hit)
-      {
-       int i;
-
-       CheckElementChangeSide(nextx, nexty, touched_element,
-                              CE_HIT_BY_SOMETHING, opposite_direction);
-
-       if (IS_CUSTOM_ELEMENT(hitting_element) &&
-           HAS_ANY_CHANGE_EVENT(hitting_element, CE_OTHER_IS_HITTING))
-       {
-         for (i = 0; i < element_info[hitting_element].num_change_pages; i++)
-         {
-           struct ElementChangeInfo *change =
-             &element_info[hitting_element].change_page[i];
-
-           if (change->can_change &&
-               change->events & CH_EVENT_BIT(CE_OTHER_IS_HITTING) &&
-               change->trigger_side & touched_side &&
-               change->trigger_element == touched_element)
-           {
-             CheckElementChangePage(newx, newy, hitting_element,
-                                    touched_element, CE_OTHER_IS_HITTING, i);
-             break;
-           }
-         }
-       }
-
-       if (IS_CUSTOM_ELEMENT(touched_element) &&
-           HAS_ANY_CHANGE_EVENT(touched_element, CE_OTHER_GETS_HIT))
-       {
-         for (i = 0; i < element_info[touched_element].num_change_pages; i++)
-         {
-           struct ElementChangeInfo *change =
-             &element_info[touched_element].change_page[i];
+    int dig_side = MV_DIR_OPPOSITE(direction);
+    struct PlayerInfo *player = PLAYERINFO(x, y);
 
-           if (change->can_change &&
-               change->events & CH_EVENT_BIT(CE_OTHER_GETS_HIT) &&
-               change->trigger_side & hitting_side &&
-               change->trigger_element == hitting_element)
-           {
-             CheckElementChangePage(nextx, nexty, touched_element,
-                                    hitting_element, CE_OTHER_GETS_HIT, i);
-             break;
-           }
-         }
-       }
-      }
-    }
-#endif
+    CheckElementChangeByPlayer(newx, newy, element, CE_PUSHED_BY_PLAYER,
+                              player->index_bit, dig_side);
+    CheckTriggeredElementChangeByPlayer(element, CE_PLAYER_PUSHES_X,
+                                       player->index_bit, dig_side);
   }
-#endif
 
+  TestIfElementTouchesCustomElement(x, y);     /* empty or new element */
+
+  TestIfElementHitsCustomElement(newx, newy, direction);
   TestIfPlayerTouchesCustomElement(newx, newy);
   TestIfElementTouchesCustomElement(newx, newy);
 }
@@ -6223,14 +5807,7 @@ void AmoebeWaechst(int x, int y)
 
     if (DelayReached(&sound_delay, sound_delay_value))
     {
-#if 1
       PlayLevelSoundElementAction(x, y, Store[x][y], ACTION_GROWING);
-#else
-      if (Store[x][y] == EL_BD_AMOEBA)
-       PlayLevelSound(x, y, SND_BD_AMOEBA_GROWING);
-      else
-       PlayLevelSound(x, y, SND_AMOEBA_GROWING);
-#endif
       sound_delay_value = 30;
     }
   }
@@ -6334,9 +5911,9 @@ void AmoebeAbleger(int ax, int ay)
     if (!IN_LEV_FIELD(x, y))
       return;
 
-    /* !!! extend EL_SAND to anything diggable (but maybe not SP_BASE) !!! */
     if (IS_FREE(x, y) ||
-       Feld[x][y] == EL_SAND || Feld[x][y] == EL_QUICKSAND_EMPTY)
+       CAN_GROW_INTO(Feld[x][y]) ||
+       Feld[x][y] == EL_QUICKSAND_EMPTY)
     {
       newax = x;
       neway = y;
@@ -6359,9 +5936,9 @@ void AmoebeAbleger(int ax, int ay)
       if (!IN_LEV_FIELD(x, y))
        continue;
 
-      /* !!! extend EL_SAND to anything diggable (but maybe not SP_BASE) !!! */
       if (IS_FREE(x, y) ||
-         Feld[x][y] == EL_SAND || Feld[x][y] == EL_QUICKSAND_EMPTY)
+         CAN_GROW_INTO(Feld[x][y]) ||
+         Feld[x][y] == EL_QUICKSAND_EMPTY)
       {
        newax = x;
        neway = y;
@@ -6373,7 +5950,7 @@ void AmoebeAbleger(int ax, int ay)
 
     if (newax == ax && neway == ay)            /* amoeba cannot grow */
     {
-      if (i == 4 && (!waiting_for_player || game.emulation == EMU_BOULDERDASH))
+      if (i == 4 && (!waiting_for_player || element == EL_BD_AMOEBA))
       {
        Feld[ax][ay] = EL_AMOEBA_DEAD;
        DrawLevelField(ax, ay);
@@ -6428,11 +6005,8 @@ void AmoebeAbleger(int ax, int ay)
   else if (neway == ay)
   {
     Feld[newax][neway] = EL_AMOEBA_DROP;       /* drop left/right of amoeba */
-#if 1
+
     PlayLevelSoundAction(newax, neway, ACTION_GROWING);
-#else
-    PlayLevelSound(newax, neway, SND_AMOEBA_GROWING);
-#endif
   }
   else
   {
@@ -6504,8 +6078,7 @@ void Life(int ax, int ay)
        changed = TRUE;
       }
     }
-    /* !!! extend EL_SAND to anything diggable (but maybe not SP_BASE) !!! */
-    else if (IS_FREE(xx, yy) || Feld[xx][yy] == EL_SAND)
+    else if (IS_FREE(xx, yy) || CAN_GROW_INTO(Feld[xx][yy]))
     {                                  /* free border field */
       if (nachbarn >= life[2] && nachbarn <= life[3])
       {
@@ -6542,7 +6115,7 @@ static void StopRobotWheel(int x, int y)
 
 static void InitTimegateWheel(int x, int y)
 {
-  ChangeDelay[x][y] = level.time_wheel * FRAMES_PER_SECOND;
+  ChangeDelay[x][y] = level.time_timegate * FRAMES_PER_SECOND;
 }
 
 static void RunTimegateWheel(int x, int y)
@@ -6607,11 +6180,8 @@ static void CloseAllOpenTimegates()
       if (element == EL_TIMEGATE_OPEN || element == EL_TIMEGATE_OPENING)
       {
        Feld[x][y] = EL_TIMEGATE_CLOSING;
-#if 1
+
        PlayLevelSoundAction(x, y, ACTION_CLOSING);
-#else
-       PlayLevelSound(x, y, SND_TIMEGATE_CLOSING);
-#endif
       }
     }
   }
@@ -6813,11 +6383,7 @@ void MauerAbleger(int ax, int ay)
     Feld[ax][ay] = EL_WALL;
 
   if (new_wall)
-#if 1
     PlayLevelSoundAction(ax, ay, ACTION_GROWING);
-#else
-    PlayLevelSound(ax, ay, SND_EXPANDABLE_WALL_GROWING);
-#endif
 }
 
 void CheckForDragon(int x, int y)
@@ -6926,212 +6492,579 @@ static void ChangeActiveTrap(int x, int y)
     DrawLevelFieldCrumbledSand(x, y);
 }
 
-static void ChangeElementNowExt(int x, int y, int target_element)
+static int getSpecialActionElement(int element, int number, int base_element)
 {
-  int previous_move_direction = MovDir[x][y];
-
-  /* check if element under player changes from accessible to unaccessible
-     (needed for special case of dropping element which then changes) */
-  if (IS_PLAYER(x, y) && !PLAYER_EXPLOSION_PROTECTED(x, y) &&
-      IS_ACCESSIBLE(Feld[x][y]) && !IS_ACCESSIBLE(target_element))
-  {
-    Bang(x, y);
-    return;
-  }
+  return (element != EL_EMPTY ? element :
+         number != -1 ? base_element + number - 1 :
+         EL_EMPTY);
+}
 
-  RemoveField(x, y);
-  Feld[x][y] = target_element;
+static int getModifiedActionNumber(int value_old, int operator, int operand,
+                                  int value_min, int value_max)
+{
+  int value_new = (operator == CA_MODE_SET      ? operand :
+                  operator == CA_MODE_ADD      ? value_old + operand :
+                  operator == CA_MODE_SUBTRACT ? value_old - operand :
+                  operator == CA_MODE_MULTIPLY ? value_old * operand :
+                  operator == CA_MODE_DIVIDE   ? value_old / MAX(1, operand) :
+                  operator == CA_MODE_MODULO   ? value_old % MAX(1, operand) :
+                  value_old);
 
-  Changed[x][y] |= ChangeEvent[x][y];  /* ignore same changes in this frame */
+  return (value_new < value_min ? value_min :
+         value_new > value_max ? value_max :
+         value_new);
+}
 
-  ResetGfxAnimation(x, y);
-  ResetRandomAnimationValue(x, y);
+static void ExecuteCustomElementAction(int x, int y, int element, int page)
+{
+  struct ElementInfo *ei = &element_info[element];
+  struct ElementChangeInfo *change = &ei->change_page[page];
+  int action_type = change->action_type;
+  int action_mode = change->action_mode;
+  int action_arg = change->action_arg;
+  int i;
 
-  if (element_info[Feld[x][y]].move_direction_initial == MV_START_PREVIOUS)
-    MovDir[x][y] = previous_move_direction;
+  if (!change->has_action)
+    return;
 
-#if 1
-  InitField_WithBug1(x, y, FALSE);
+  /* ---------- determine action paramater values ---------- */
+
+  int action_arg_element =
+    (action_arg == CA_ARG_PLAYER_TRIGGER  ? change->actual_trigger_player :
+     action_arg == CA_ARG_ELEMENT_TRIGGER ? change->actual_trigger_element :
+     action_arg == CA_ARG_ELEMENT_TARGET  ? change->target_element :
+     EL_EMPTY);
+
+  int action_arg_number_min =
+    (action_type == CA_SET_PLAYER_SPEED ? MOVE_STEPSIZE_MIN :
+     CA_ARG_MIN);
+
+  int action_arg_number_max =
+    (action_type == CA_SET_PLAYER_SPEED ? MOVE_STEPSIZE_MAX :
+     action_type == CA_SET_GEMS ? 999 :
+     action_type == CA_SET_TIME ? 9999 :
+     action_type == CA_SET_SCORE ? 99999 :
+     action_type == CA_SET_CE_SCORE ? 9999 :
+     action_type == CA_SET_CE_COUNT ? 9999 :
+     CA_ARG_MAX);
+
+  int action_arg_number_reset =
+    (action_type == CA_SET_PLAYER_SPEED ? TILEX/game.initial_move_delay_value :
+     action_type == CA_SET_GEMS ? level.gems_needed :
+     action_type == CA_SET_TIME ? level.time :
+     action_type == CA_SET_SCORE ? 0 :
+     action_type == CA_SET_CE_SCORE ? 0 :
+     action_type == CA_SET_CE_COUNT ? ei->collect_count_initial :
+     0);
+
+  int action_arg_number_normal =
+    (action_type == CA_SET_PLAYER_SPEED ? MOVE_STEPSIZE_NORMAL :
+     action_arg_number_reset);
+
+  int action_arg_number =
+    (action_arg <= CA_ARG_MAX ? action_arg :
+     action_arg == CA_ARG_NUMBER_MIN ? action_arg_number_min :
+     action_arg == CA_ARG_NUMBER_MAX ? action_arg_number_max :
+     action_arg == CA_ARG_NUMBER_RESET ? action_arg_number_reset :
+     action_arg == CA_ARG_NUMBER_NORMAL ? action_arg_number_normal :
+     action_arg == CA_ARG_NUMBER_CE_SCORE ? ei->collect_score :
+#if USE_NEW_COLLECT_COUNT
+     action_arg == CA_ARG_NUMBER_CE_COUNT ? Count[x][y] :
 #else
-  InitField(x, y, FALSE);
-  if (CAN_MOVE(Feld[x][y]))
-    InitMovDir(x, y);
-#endif
-
-  DrawLevelField(x, y);
+     action_arg == CA_ARG_NUMBER_CE_COUNT ? ei->collect_count_initial :
+#endif
+     action_arg == CA_ARG_NUMBER_CE_DELAY ? GET_CHANGE_DELAY(change) :
+     -1);
+
+  int action_arg_number_old =
+    (action_type == CA_SET_GEMS ? local_player->gems_still_needed :
+     action_type == CA_SET_TIME ? TimeLeft :
+     action_type == CA_SET_SCORE ? local_player->score :
+     action_type == CA_SET_CE_SCORE ? ei->collect_score :
+     action_type == CA_SET_CE_COUNT ? Count[x][y] :
+     0);
+
+  int action_arg_number_new =
+    getModifiedActionNumber(action_arg_number_old,
+                           action_mode, action_arg_number,
+                           action_arg_number_min, action_arg_number_max);
+
+  /* (for explicit player choice, set invalid value to "no player") */
+  int action_arg_player_bits =
+    (action_arg == CA_ARG_PLAYER_ANY ? action_arg - CA_ARG_PLAYER :
+     action_arg >= CA_ARG_PLAYER_1 &&
+     action_arg <= CA_ARG_PLAYER_4 ? action_arg - CA_ARG_PLAYER :
+     action_arg >= CA_ARG_1 &&
+     action_arg <= CA_ARG_PLAYER_4 ? (1 << (action_arg - 1)) :
+     action_arg_element >= EL_PLAYER_1 &&
+     action_arg_element <= EL_PLAYER_4 ?
+     (1 << (action_arg_element - EL_PLAYER_1)) :
+     0);
+
+  /* (for implicit player choice, set invalid value to "all players") */
+  int trigger_player_bits =
+    (change->actual_trigger_player >= EL_PLAYER_1 &&
+     change->actual_trigger_player <= EL_PLAYER_4 ?
+     (1 << (change->actual_trigger_player - EL_PLAYER_1)) :
+     PLAYER_BITS_ANY);
+
+  /* ---------- execute action  ---------- */
+
+  switch(action_type)
+  {
+    case CA_NO_ACTION:
+    {
+      return;
+    }
 
-  if (GFX_CRUMBLED(Feld[x][y]))
-    DrawLevelFieldCrumbledSandNeighbours(x, y);
+    case CA_EXIT_PLAYER:
+    {
+      for (i = 0; i < MAX_PLAYERS; i++)
+       if (action_arg_player_bits & (1 << i))
+         stored_player[i].LevelSolved = stored_player[i].GameOver = TRUE;
 
-  TestIfBadThingTouchesHero(x, y);
-  TestIfPlayerTouchesCustomElement(x, y);
-  TestIfElementTouchesCustomElement(x, y);
+      break;
+    }
 
-  if (ELEM_IS_PLAYER(target_element))
-    RelocatePlayer(x, y, target_element);
-}
+    case CA_KILL_PLAYER:
+    {
+      for (i = 0; i < MAX_PLAYERS; i++)
+       if (action_arg_player_bits & (1 << i))
+         KillPlayer(&stored_player[i]);
 
-static boolean ChangeElementNow(int x, int y, int element, int page)
-{
-  struct ElementChangeInfo *change = &element_info[element].change_page[page];
-  int target_element;
+      break;
+    }
 
-  /* always use default change event to prevent running into a loop */
-  if (ChangeEvent[x][y] == CE_BITMASK_DEFAULT)
-    ChangeEvent[x][y] = CH_EVENT_BIT(CE_DELAY);
+    case CA_RESTART_LEVEL:
+    {
+      game.restart_level = TRUE;
 
-  if (ChangeEvent[x][y] == CH_EVENT_BIT(CE_DELAY))
-  {
-    /* reset actual trigger element and player */
-    change->actual_trigger_element = EL_EMPTY;
-    change->actual_trigger_player = EL_PLAYER_1;
-  }
+      break;
+    }
 
-  /* do not change already changed elements with same change event */
-#if 0
-  if (Changed[x][y] & ChangeEvent[x][y])
-    return FALSE;
-#else
-  if (Changed[x][y])
-    return FALSE;
-#endif
+    case CA_SHOW_ENVELOPE:
+    {
+      int element = getSpecialActionElement(action_arg_element,
+                                           action_arg_number, EL_ENVELOPE_1);
 
-  Changed[x][y] |= ChangeEvent[x][y];  /* ignore same changes in this frame */
+      if (IS_ENVELOPE(element))
+       local_player->show_envelope = element;
 
-  CheckTriggeredElementChangePage(x,y, Feld[x][y], CE_OTHER_IS_CHANGING, page);
+      break;
+    }
 
-  if (change->explode)
-  {
-    Bang(x, y);
+    case CA_ADD_KEY:
+    {
+      int element = getSpecialActionElement(action_arg_element,
+                                           action_arg_number, EL_KEY_1);
 
-    return TRUE;
-  }
+      if (IS_KEY(element))
+      {
+       for (i = 0; i < MAX_PLAYERS; i++)
+       {
+         if (trigger_player_bits & (1 << i))
+         {
+           stored_player[i].key[KEY_NR(element)] = TRUE;
 
-  if (change->use_target_content)
-  {
-    boolean complete_replace = TRUE;
-    boolean can_replace[3][3];
-    int xx, yy;
+           DrawGameValue_Keys(stored_player[i].key);
 
-    for (yy = 0; yy < 3; yy++) for (xx = 0; xx < 3 ; xx++)
-    {
-      boolean is_empty;
-      boolean is_diggable;
-      boolean is_destructible;
-      int ex = x + xx - 1;
-      int ey = y + yy - 1;
-      int content_element = change->target_content[xx][yy];
-      int e;
+           redraw_mask |= REDRAW_DOOR_1;
+         }
+       }
+      }
 
-      can_replace[xx][yy] = TRUE;
+      break;
+    }
 
-      if (ex == x && ey == y)  /* do not check changing element itself */
-       continue;
+    case CA_DEL_KEY:
+    {
+      int element = getSpecialActionElement(action_arg_element,
+                                           action_arg_number, EL_KEY_1);
 
-      if (content_element == EL_EMPTY_SPACE)
+      if (IS_KEY(element))
       {
-       can_replace[xx][yy] = FALSE;    /* do not replace border with space */
+       for (i = 0; i < MAX_PLAYERS; i++)
+       {
+         if (trigger_player_bits & (1 << i))
+         {
+           stored_player[i].key[KEY_NR(element)] = FALSE;
 
-       continue;
+           DrawGameValue_Keys(stored_player[i].key);
+
+           redraw_mask |= REDRAW_DOOR_1;
+         }
+       }
       }
 
-      if (!IN_LEV_FIELD(ex, ey))
-      {
-       can_replace[xx][yy] = FALSE;
-       complete_replace = FALSE;
+      break;
+    }
 
-       continue;
-      }
+    case CA_SET_PLAYER_SPEED:
+    {
+      for (i = 0; i < MAX_PLAYERS; i++)
+      {
+       if (trigger_player_bits & (1 << i))
+       {
+         int move_stepsize = TILEX / stored_player[i].move_delay_value;
 
-      e = Feld[ex][ey];
+         if (action_mode == CA_MODE_ADD || action_mode == CA_MODE_SUBTRACT)
+         {
+           /* translate "+" and "-" to "*" and "/" with powers of two */
+           action_arg_number = 1 << action_arg_number;
+           action_mode = (action_mode == CA_MODE_ADD ? CA_MODE_MULTIPLY :
+                          CA_MODE_DIVIDE);
+         }
 
-      if (IS_MOVING(ex, ey) || IS_BLOCKED(ex, ey))
-       e = MovingOrBlocked2Element(ex, ey);
+         move_stepsize =
+           getModifiedActionNumber(move_stepsize,
+                                   action_mode,
+                                   action_arg_number,
+                                   action_arg_number_min,
+                                   action_arg_number_max);
 
-#if 1
-      is_empty = (IS_FREE(ex, ey) || (IS_PLAYER(ex, ey) &&
-                                     IS_WALKABLE(content_element)));
-      is_diggable = (is_empty || IS_DIGGABLE(e));
-      is_destructible = (is_empty || !IS_INDESTRUCTIBLE(e));
+         /* make sure that value is power of 2 */
+         move_stepsize = (1 << log_2(move_stepsize));
 
-      can_replace[xx][yy] =
-       ((change->replace_when == CP_WHEN_EMPTY && is_empty) ||
-        (change->replace_when == CP_WHEN_DIGGABLE && is_diggable) ||
-        (change->replace_when == CP_WHEN_DESTRUCTIBLE && is_destructible));
+         stored_player[i].move_delay_value = TILEX / move_stepsize;
 
-      if (!can_replace[xx][yy])
-       complete_replace = FALSE;
-#else
-      empty_for_element = (IS_FREE(ex, ey) || (IS_FREE_OR_PLAYER(ex, ey) &&
-                                              IS_WALKABLE(content_element)));
-#if 1
-      half_destructible = (empty_for_element || IS_DIGGABLE(e));
-#else
-      half_destructible = (IS_FREE(ex, ey) || IS_DIGGABLE(e));
+#if 0
+         printf("::: move_delay_value == %d [%d]\n",
+                stored_player[i].move_delay_value, action_arg_number);
 #endif
-
-      if ((change->replace_when <= CP_WHEN_EMPTY  && !empty_for_element) ||
-         (change->replace_when <= CP_WHEN_DIGGABLE && !half_destructible) ||
-         (change->replace_when <= CP_WHEN_DESTRUCTIBLE && IS_INDESTRUCTIBLE(e)))
-      {
-       can_replace[xx][yy] = FALSE;
-       complete_replace = FALSE;
+       }
       }
-#endif
+
+      break;
     }
 
-    if (!change->only_if_complete || complete_replace)
+    case CA_SET_GEMS:
     {
-      boolean something_has_changed = FALSE;
+      local_player->gems_still_needed = action_arg_number_new;
 
-      if (change->only_if_complete && change->use_random_replace &&
-         RND(100) < change->random_percentage)
-       return FALSE;
+      DrawGameValue_Emeralds(local_player->gems_still_needed);
 
-      for (yy = 0; yy < 3; yy++) for (xx = 0; xx < 3 ; xx++)
-      {
-       int ex = x + xx - 1;
-       int ey = y + yy - 1;
-       int content_element;
+      break;
+    }
 
-       if (can_replace[xx][yy] && (!change->use_random_replace ||
-                                   RND(100) < change->random_percentage))
-       {
-         if (IS_MOVING(ex, ey) || IS_BLOCKED(ex, ey))
-           RemoveMovingField(ex, ey);
+    case CA_SET_TIME:
+    {
+      if (level.time > 0)      /* only modify limited time value */
+      {
+       TimeLeft = action_arg_number_new;
 
-         ChangeEvent[ex][ey] = ChangeEvent[x][y];
+       DrawGameValue_Time(TimeLeft);
 
-         content_element = change->target_content[xx][yy];
-         target_element = GET_TARGET_ELEMENT(content_element, change);
+       if (!TimeLeft && setup.time_limit)
+         for (i = 0; i < MAX_PLAYERS; i++)
+           KillPlayer(&stored_player[i]);
+      }
 
-         ChangeElementNowExt(ex, ey, target_element);
+      break;
+    }
 
-         something_has_changed = TRUE;
+    case CA_SET_SCORE:
+    {
+      local_player->score = action_arg_number_new;
 
-         /* for symmetry reasons, freeze newly created border elements */
-         if (ex != x || ey != y)
-           Stop[ex][ey] = TRUE;        /* no more moving in this frame */
-       }
-      }
+      DrawGameValue_Score(local_player->score);
 
-      if (something_has_changed)
-       PlayLevelSoundElementAction(x, y, element, ACTION_CHANGING);
+      break;
     }
-  }
-  else
-  {
-    target_element = GET_TARGET_ELEMENT(change->target_element, change);
 
-    ChangeElementNowExt(x, y, target_element);
+    case CA_SET_CE_SCORE:
+    {
+      ei->collect_score = action_arg_number_new;
 
-    PlayLevelSoundElementAction(x, y, element, ACTION_CHANGING);
-  }
+      break;
+    }
 
-  return TRUE;
-}
+    case CA_SET_CE_COUNT:
+    {
+#if USE_NEW_COLLECT_COUNT
+      int count_last = Count[x][y];
 
-static void ChangeElement(int x, int y, int page)
+      Count[x][y] = action_arg_number_new;
+
+#if 0
+      printf("::: Count == %d\n", Count[x][y]);
+#endif
+
+      if (Count[x][y] == 0 && count_last > 0)
+      {
+#if 0
+       printf("::: CE_COUNT_AT_ZERO\n");
+#endif
+
+       CheckElementChange(x, y, element, EL_UNDEFINED, CE_COUNT_AT_ZERO);
+       CheckTriggeredElementChange(element, CE_COUNT_AT_ZERO_OF_X);
+      }
+#endif
+
+      break;
+    }
+
+    case CA_SET_DYNABOMB_NUMBER:
+    {
+      printf("::: CA_SET_DYNABOMB_NUMBER -- not yet implemented\n");
+
+      break;
+    }
+
+    case CA_SET_DYNABOMB_SIZE:
+    {
+      printf("::: CA_SET_DYNABOMB_SIZE -- not yet implemented\n");
+
+      break;
+    }
+
+    case CA_SET_DYNABOMB_POWER:
+    {
+      printf("::: CA_SET_DYNABOMB_POWER -- not yet implemented\n");
+
+      break;
+    }
+
+    case CA_TOGGLE_PLAYER_GRAVITY:
+    {
+      game.gravity = !game.gravity;
+
+      break;
+    }
+
+    case CA_ENABLE_PLAYER_GRAVITY:
+    {
+      game.gravity = TRUE;
+
+      break;
+    }
+
+    case CA_DISABLE_PLAYER_GRAVITY:
+    {
+      game.gravity = FALSE;
+
+      break;
+    }
+
+    default:
+      break;
+  }
+}
+
+static void ChangeElementNowExt(struct ElementChangeInfo *change,
+                               int x, int y, int target_element)
+{
+  int previous_move_direction = MovDir[x][y];
+  boolean add_player = (ELEM_IS_PLAYER(target_element) &&
+                       IS_WALKABLE(Feld[x][y]));
+
+  /* check if element under player changes from accessible to unaccessible
+     (needed for special case of dropping element which then changes) */
+  if (IS_PLAYER(x, y) && !PLAYER_EXPLOSION_PROTECTED(x, y) &&
+      IS_ACCESSIBLE(Feld[x][y]) && !IS_ACCESSIBLE(target_element))
+  {
+    Bang(x, y);
+    return;
+  }
+
+  if (!add_player)
+  {
+    if (IS_MOVING(x, y) || IS_BLOCKED(x, y))
+      RemoveMovingField(x, y);
+    else
+      RemoveField(x, y);
+
+    Feld[x][y] = target_element;
+
+    ResetGfxAnimation(x, y);
+    ResetRandomAnimationValue(x, y);
+
+    if (element_info[Feld[x][y]].move_direction_initial == MV_START_PREVIOUS)
+      MovDir[x][y] = previous_move_direction;
+
+    InitField_WithBug1(x, y, FALSE);
+
+    DrawLevelField(x, y);
+
+    if (GFX_CRUMBLED(Feld[x][y]))
+      DrawLevelFieldCrumbledSandNeighbours(x, y);
+  }
+
+  /* "Changed[][]" not set yet to allow "entered by player" change one time */
+  if (ELEM_IS_PLAYER(target_element))
+    RelocatePlayer(x, y, target_element);
+
+#if 1
+  Changed[x][y] = TRUE;                /* ignore all further changes in this frame */
+#else
+  Changed[x][y] |= ChangeEvent[x][y];  /* ignore same changes in this frame */
+#endif
+
+  TestIfBadThingTouchesPlayer(x, y);
+  TestIfPlayerTouchesCustomElement(x, y);
+  TestIfElementTouchesCustomElement(x, y);
+}
+
+static boolean ChangeElementNow(int x, int y, int element, int page)
+{
+  struct ElementChangeInfo *change = &element_info[element].change_page[page];
+  int target_element;
+  int old_element = Feld[x][y];
+
+  /* always use default change event to prevent running into a loop */
+  if (ChangeEvent[x][y] == -1)
+    ChangeEvent[x][y] = CE_DELAY;
+
+  if (ChangeEvent[x][y] == CE_DELAY)
+  {
+    /* reset actual trigger element, trigger player and action element */
+    change->actual_trigger_element = EL_EMPTY;
+    change->actual_trigger_player = EL_PLAYER_1;
+  }
+
+#if 1
+  /* do not change any elements that have already changed in this frame */
+  if (Changed[x][y])
+    return FALSE;
+#else
+  /* do not change already changed elements with same change event */
+  if (Changed[x][y] & ChangeEvent[x][y])
+    return FALSE;
+#endif
+
+#if 1
+  Changed[x][y] = TRUE;                /* ignore all further changes in this frame */
+#else
+  Changed[x][y] |= ChangeEvent[x][y];  /* ignore same changes in this frame */
+#endif
+
+  if (change->explode)
+  {
+    Bang(x, y);
+
+    return TRUE;
+  }
+
+  if (change->use_target_content)
+  {
+    boolean complete_replace = TRUE;
+    boolean can_replace[3][3];
+    int xx, yy;
+
+    for (yy = 0; yy < 3; yy++) for (xx = 0; xx < 3 ; xx++)
+    {
+      boolean is_empty;
+      boolean is_walkable;
+      boolean is_diggable;
+      boolean is_collectible;
+      boolean is_removable;
+      boolean is_destructible;
+      int ex = x + xx - 1;
+      int ey = y + yy - 1;
+      int content_element = change->target_content[xx][yy];
+      int e;
+
+      can_replace[xx][yy] = TRUE;
+
+      if (ex == x && ey == y)  /* do not check changing element itself */
+       continue;
+
+      if (content_element == EL_EMPTY_SPACE)
+      {
+       can_replace[xx][yy] = FALSE;    /* do not replace border with space */
+
+       continue;
+      }
+
+      if (!IN_LEV_FIELD(ex, ey))
+      {
+       can_replace[xx][yy] = FALSE;
+       complete_replace = FALSE;
+
+       continue;
+      }
+
+      e = Feld[ex][ey];
+
+      if (IS_MOVING(ex, ey) || IS_BLOCKED(ex, ey))
+       e = MovingOrBlocked2Element(ex, ey);
+
+      is_empty = (IS_FREE(ex, ey) ||
+                 (IS_FREE_OR_PLAYER(ex, ey) && IS_WALKABLE(content_element)));
+
+      is_walkable     = (is_empty || IS_WALKABLE(e));
+      is_diggable     = (is_empty || IS_DIGGABLE(e));
+      is_collectible  = (is_empty || IS_COLLECTIBLE(e));
+      is_destructible = (is_empty || !IS_INDESTRUCTIBLE(e));
+      is_removable    = (is_diggable || is_collectible);
+
+      can_replace[xx][yy] =
+       (((change->replace_when == CP_WHEN_EMPTY        && is_empty) ||
+         (change->replace_when == CP_WHEN_WALKABLE     && is_walkable) ||
+         (change->replace_when == CP_WHEN_DIGGABLE     && is_diggable) ||
+         (change->replace_when == CP_WHEN_COLLECTIBLE  && is_collectible) ||
+         (change->replace_when == CP_WHEN_REMOVABLE    && is_removable) ||
+         (change->replace_when == CP_WHEN_DESTRUCTIBLE && is_destructible)) &&
+        !(IS_PLAYER(ex, ey) && ELEM_IS_PLAYER(content_element)));
+
+      if (!can_replace[xx][yy])
+       complete_replace = FALSE;
+    }
+
+    if (!change->only_if_complete || complete_replace)
+    {
+      boolean something_has_changed = FALSE;
+
+      if (change->only_if_complete && change->use_random_replace &&
+         RND(100) < change->random_percentage)
+       return FALSE;
+
+      for (yy = 0; yy < 3; yy++) for (xx = 0; xx < 3 ; xx++)
+      {
+       int ex = x + xx - 1;
+       int ey = y + yy - 1;
+       int content_element;
+
+       if (can_replace[xx][yy] && (!change->use_random_replace ||
+                                   RND(100) < change->random_percentage))
+       {
+         if (IS_MOVING(ex, ey) || IS_BLOCKED(ex, ey))
+           RemoveMovingField(ex, ey);
+
+         ChangeEvent[ex][ey] = ChangeEvent[x][y];
+
+         content_element = change->target_content[xx][yy];
+         target_element = GET_TARGET_ELEMENT(content_element, change);
+
+         ChangeElementNowExt(change, ex, ey, target_element);
+
+         something_has_changed = TRUE;
+
+         /* for symmetry reasons, freeze newly created border elements */
+         if (ex != x || ey != y)
+           Stop[ex][ey] = TRUE;        /* no more moving in this frame */
+       }
+      }
+
+      if (something_has_changed)
+       PlayLevelSoundElementAction(x, y, element, ACTION_CHANGING);
+    }
+  }
+  else
+  {
+    target_element = GET_TARGET_ELEMENT(change->target_element, change);
+
+    ChangeElementNowExt(change, x, y, target_element);
+
+    PlayLevelSoundElementAction(x, y, element, ACTION_CHANGING);
+  }
+
+  /* this uses direct change before indirect change */
+  CheckTriggeredElementChangeByPage(old_element, CE_CHANGE_OF_X, page);
+
+  return TRUE;
+}
+
+static void ChangeElement(int x, int y, int page)
 {
   int element = MovingOrBlocked2Element(x, y);
   struct ElementInfo *ei = &element_info[element];
@@ -7161,8 +7094,7 @@ static void ChangeElement(int x, int y, int page)
 
   if (ChangeDelay[x][y] == 0)          /* initialize element change */
   {
-    ChangeDelay[x][y] = (    change->delay_fixed  * change->delay_frames +
-                        RND(change->delay_random * change->delay_frames)) + 1;
+    ChangeDelay[x][y] = GET_CHANGE_DELAY(change) + 1;
 
     ResetGfxAnimation(x, y);
     ResetRandomAnimationValue(x, y);
@@ -7193,11 +7125,7 @@ static void ChangeElement(int x, int y, int page)
       change = &ei->change_page[page];
     }
 
-#if 0
-    if (IS_MOVING(x, y) && !change->explode)
-#else
     if (IS_MOVING(x, y))               /* never change a running system ;-) */
-#endif
     {
       ChangeDelay[x][y] = 1;           /* try change after next move step */
       ChangePage[x][y] = page;         /* remember page to use for change */
@@ -7213,76 +7141,74 @@ static void ChangeElement(int x, int y, int page)
   }
 }
 
-static boolean CheckTriggeredElementChangeExt(int lx, int ly,
-                                             int trigger_element,
+static boolean CheckTriggeredElementChangeExt(int trigger_element,
                                              int trigger_event,
                                              int trigger_player,
                                              int trigger_side,
                                              int trigger_page)
 {
-  int i, j, x, y;
+  boolean change_done_any = FALSE;
   int trigger_page_bits = (trigger_page < 0 ? CH_PAGE_ANY : 1 << trigger_page);
+  int i;
 
-  if (!(trigger_events[trigger_element] & CH_EVENT_BIT(trigger_event)))
+  if (!(trigger_events[trigger_element][trigger_event]))
     return FALSE;
 
   for (i = 0; i < NUM_CUSTOM_ELEMENTS; i++)
   {
     int element = EL_CUSTOM_START + i;
+    boolean change_done = FALSE;
+    int p;
 
-    boolean change_element = FALSE;
-    int page = 0;
-
-    if (!CAN_CHANGE(element) || !HAS_ANY_CHANGE_EVENT(element, trigger_event))
+    if (!CAN_CHANGE_OR_HAS_ACTION(element) ||
+       !HAS_ANY_CHANGE_EVENT(element, trigger_event))
       continue;
 
-    for (j = 0; j < element_info[element].num_change_pages; j++)
+    for (p = 0; p < element_info[element].num_change_pages; p++)
     {
-      struct ElementChangeInfo *change = &element_info[element].change_page[j];
+      struct ElementChangeInfo *change = &element_info[element].change_page[p];
 
-      if (change->can_change &&
-         change->events & CH_EVENT_BIT(trigger_event) &&
+      if (change->can_change_or_has_action &&
+         change->has_event[trigger_event] &&
          change->trigger_side & trigger_side &&
          change->trigger_player & trigger_player &&
          change->trigger_page & trigger_page_bits &&
          IS_EQUAL_OR_IN_GROUP(trigger_element, change->trigger_element))
       {
-#if 0
-       if (!(change->events & CH_EVENT_BIT(trigger_event)))
-         printf("::: !!! %d triggers %d: using wrong page %d [event %d]\n",
-                trigger_element-EL_CUSTOM_START+1, i+1, j, trigger_event);
-#endif
-
-       change_element = TRUE;
-       page = j;
-
        change->actual_trigger_element = trigger_element;
        change->actual_trigger_player = EL_PLAYER_1 + log_2(trigger_player);
 
-       break;
-      }
-    }
-
-    if (!change_element)
-      continue;
+       if ((change->can_change && !change_done) || change->has_action)
+       {
+         int x, y;
 
-    for (y = 0; y < lev_fieldy; y++) for (x = 0; x < lev_fieldx; x++)
-    {
-#if 0
-      if (x == lx && y == ly)  /* do not change trigger element itself */
-       continue;
-#endif
+         for (y = 0; y < lev_fieldy; y++) for (x = 0; x < lev_fieldx; x++)
+         {
+           if (Feld[x][y] == element)
+           {
+             if (change->can_change && !change_done)
+             {
+               ChangeDelay[x][y] = 1;
+               ChangeEvent[x][y] = trigger_event;
+               ChangeElement(x, y, p);
+             }
+
+             if (change->has_action)
+               ExecuteCustomElementAction(x, y, element, p);
+           }
+         }
 
-      if (Feld[x][y] == element)
-      {
-       ChangeDelay[x][y] = 1;
-       ChangeEvent[x][y] = CH_EVENT_BIT(trigger_event);
-       ChangeElement(x, y, page);
+         if (change->can_change)
+         {
+           change_done = TRUE;
+           change_done_any = TRUE;
+         }
+       }
       }
     }
   }
 
-  return TRUE;
+  return change_done_any;
 }
 
 static boolean CheckElementChangeExt(int x, int y,
@@ -7290,10 +7216,13 @@ static boolean CheckElementChangeExt(int x, int y,
                                     int trigger_element,
                                     int trigger_event,
                                     int trigger_player,
-                                    int trigger_side,
-                                    int trigger_page)
+                                    int trigger_side)
 {
-  if (!CAN_CHANGE(element) || !HAS_ANY_CHANGE_EVENT(element, trigger_event))
+  boolean change_done = FALSE;
+  int p;
+
+  if (!CAN_CHANGE_OR_HAS_ACTION(element) ||
+      !HAS_ANY_CHANGE_EVENT(element, trigger_event))
     return FALSE;
 
   if (Feld[x][y] == EL_BLOCKED)
@@ -7302,73 +7231,43 @@ static boolean CheckElementChangeExt(int x, int y,
     element = Feld[x][y];
   }
 
-#if 1
   if (Feld[x][y] != element)   /* check if element has already changed */
-  {
-#if 0
-    printf("::: %d ('%s') != %d ('%s') [%d]\n",
-          Feld[x][y], element_info[Feld[x][y]].token_name,
-          element, element_info[element].token_name,
-          trigger_event);
-#endif
-
     return FALSE;
-  }
-#endif
 
-#if 1
-  if (trigger_page < 0)
+  for (p = 0; p < element_info[element].num_change_pages; p++)
   {
-    boolean change_element = FALSE;
-    int i;
+    struct ElementChangeInfo *change = &element_info[element].change_page[p];
+
+    boolean check_trigger_element =
+      (trigger_event == CE_TOUCHING_X ||
+       trigger_event == CE_HITTING_X ||
+       trigger_event == CE_HIT_BY_X);
 
-    for (i = 0; i < element_info[element].num_change_pages; i++)
+    if (change->can_change_or_has_action &&
+       change->has_event[trigger_event] &&
+       change->trigger_side & trigger_side &&
+       change->trigger_player & trigger_player &&
+       (!check_trigger_element ||
+        IS_EQUAL_OR_IN_GROUP(trigger_element, change->trigger_element)))
     {
-      struct ElementChangeInfo *change = &element_info[element].change_page[i];
+      change->actual_trigger_element = trigger_element;
+      change->actual_trigger_player = EL_PLAYER_1 + log_2(trigger_player);
 
-      if (change->can_change &&
-         change->events & CH_EVENT_BIT(trigger_event) &&
-         change->trigger_side & trigger_side &&
-         change->trigger_player & trigger_player)
+      if (change->can_change && !change_done)
       {
-       change_element = TRUE;
-       trigger_page = i;
-
-       change->actual_trigger_element = trigger_element;
-       change->actual_trigger_player = EL_PLAYER_1 + log_2(trigger_player);
+       ChangeDelay[x][y] = 1;
+       ChangeEvent[x][y] = trigger_event;
+       ChangeElement(x, y, p);
 
-       break;
+       change_done = TRUE;
       }
-    }
-
-    if (!change_element)
-      return FALSE;
-  }
-  else
-  {
-    struct ElementInfo *ei = &element_info[element];
-    struct ElementChangeInfo *change = &ei->change_page[trigger_page];
 
-    change->actual_trigger_element = trigger_element;
-    change->actual_trigger_player = EL_PLAYER_1;       /* unused */
+      if (change->has_action)
+       ExecuteCustomElementAction(x, y, element, p);
+    }
   }
 
-#else
-
-  /* !!! this check misses pages with same event, but different side !!! */
-
-  if (trigger_page < 0)
-    trigger_page = element_info[element].event_page_nr[trigger_event];
-
-  if (!(element_info[element].change_page[trigger_page].trigger_side & trigger_side))
-    return FALSE;
-#endif
-
-  ChangeDelay[x][y] = 1;
-  ChangeEvent[x][y] = CH_EVENT_BIT(trigger_event);
-  ChangeElement(x, y, trigger_page);
-
-  return TRUE;
+  return change_done;
 }
 
 static void PlayPlayerSound(struct PlayerInfo *player)
@@ -7533,13 +7432,8 @@ static void SetPlayerWaiting(struct PlayerInfo *player, boolean is_waiting)
   }
 }
 
-#if 1
 static byte PlayerActions(struct PlayerInfo *player, byte player_action)
 {
-#if 0
-  static byte stored_player_action[MAX_PLAYERS];
-  static int num_stored_actions = 0;
-#endif
   boolean moved = FALSE, snapped = FALSE, dropped = FALSE;
   int left     = player_action & JOY_LEFT;
   int right    = player_action & JOY_RIGHT;
@@ -7550,34 +7444,11 @@ static byte PlayerActions(struct PlayerInfo *player, byte player_action)
   int dx       = (left ? -1    : right ? 1     : 0);
   int dy       = (up   ? -1    : down  ? 1     : 0);
 
-#if 0
-  stored_player_action[player->index_nr] = 0;
-  num_stored_actions++;
-#endif
-
-#if 0
-  printf("::: player %d [%d]\n", player->index_nr, FrameCounter);
-#endif
-
   if (!player->active || tape.pausing)
     return 0;
 
-#if 0
-  printf("::: [%d %d %d %d] [%d %d]\n",
-        left, right, up, down, button1, button2);
-#endif
-
   if (player_action)
   {
-#if 0
-    printf("::: player %d acts [%d]\n", player->index_nr, FrameCounter);
-#endif
-
-#if 0
-    /* !!! TEST !!! */
-    if (player->MovPos == 0)
-      CheckGravityMovement(player);
-#endif
     if (button1)
       snapped = SnapField(player, dx, dy);
     else
@@ -7599,18 +7470,10 @@ static byte PlayerActions(struct PlayerInfo *player, byte player_action)
 
     SetPlayerWaiting(player, FALSE);
 
-#if 1
     return player_action;
-#else
-    stored_player_action[player->index_nr] = player_action;
-#endif
   }
   else
   {
-#if 0
-    printf("::: player %d waits [%d]\n", player->index_nr, FrameCounter);
-#endif
-
     /* no actions for this player (no input at player's configured device) */
 
     DigField(player, 0, 0, 0, 0, 0, 0, DF_NO_PUSH);
@@ -7627,170 +7490,107 @@ static byte PlayerActions(struct PlayerInfo *player, byte player_action)
 
     return 0;
   }
-
-#if 0
-  if (tape.recording && num_stored_actions >= MAX_PLAYERS)
-  {
-    printf("::: player %d recorded [%d]\n", player->index_nr, FrameCounter);
-
-    TapeRecordAction(stored_player_action);
-    num_stored_actions = 0;
-  }
-#endif
 }
 
-#else
-
-static void PlayerActions(struct PlayerInfo *player, byte player_action)
+void AdvanceFrameAndPlayerCounters(int player_nr)
 {
-  static byte stored_player_action[MAX_PLAYERS];
-  static int num_stored_actions = 0;
-  boolean moved = FALSE, snapped = FALSE, dropped = FALSE;
-  int left     = player_action & JOY_LEFT;
-  int right    = player_action & JOY_RIGHT;
-  int up       = player_action & JOY_UP;
-  int down     = player_action & JOY_DOWN;
-  int button1  = player_action & JOY_BUTTON_1;
-  int button2  = player_action & JOY_BUTTON_2;
-  int dx       = (left ? -1    : right ? 1     : 0);
-  int dy       = (up   ? -1    : down  ? 1     : 0);
-
-  stored_player_action[player->index_nr] = 0;
-  num_stored_actions++;
-
-  printf("::: player %d [%d]\n", player->index_nr, FrameCounter);
+  int i;
 
-  if (!player->active || tape.pausing)
-    return;
+  /* advance frame counters (global frame counter and time frame counter) */
+  FrameCounter++;
+  TimeFrames++;
 
-  if (player_action)
+  /* advance player counters (counters for move delay, move animation etc.) */
+  for (i = 0; i < MAX_PLAYERS; i++)
   {
-    printf("::: player %d acts [%d]\n", player->index_nr, FrameCounter);
-
-    if (button1)
-      snapped = SnapField(player, dx, dy);
-    else
-    {
-      if (button2)
-       dropped = DropElement(player);
+    boolean advance_player_counters = (player_nr == -1 || player_nr == i);
+    int move_delay_value = stored_player[i].move_delay_value;
+    int move_frames = MOVE_DELAY_NORMAL_SPEED / move_delay_value;
 
-      moved = MovePlayer(player, dx, dy);
-    }
+    if (!advance_player_counters)      /* not all players may be affected */
+      continue;
 
-    if (tape.single_step && tape.recording && !tape.pausing)
+#if USE_NEW_PLAYER_ANIM
+    if (move_frames == 0)      /* less than one move per game frame */
     {
-      if (button1 || (dropped && !moved))
-      {
-       TapeTogglePause(TAPE_TOGGLE_AUTOMATIC);
-       SnapField(player, 0, 0);                /* stop snapping */
-      }
-    }
-
-    stored_player_action[player->index_nr] = player_action;
-  }
-  else
-  {
-    printf("::: player %d waits [%d]\n", player->index_nr, FrameCounter);
+      int stepsize = TILEX / move_delay_value;
+      int delay = move_delay_value / MOVE_DELAY_NORMAL_SPEED;
+      int count = (stored_player[i].is_moving ?
+                  ABS(stored_player[i].MovPos) / stepsize : FrameCounter);
 
-    /* no actions for this player (no input at player's configured device) */
+      if (count % delay == 0)
+       move_frames = 1;
+    }
+#endif
 
-    DigField(player, 0, 0, 0, 0, 0, 0, DF_NO_PUSH);
-    SnapField(player, 0, 0);
-    CheckGravityMovementWhenNotMoving(player);
+    stored_player[i].Frame += move_frames;
 
-    if (player->MovPos == 0)
-      InitPlayerGfxAnimation(player, ACTION_DEFAULT, player->MovDir);
+    if (stored_player[i].MovPos != 0)
+      stored_player[i].StepFrame += move_frames;
 
-    if (player->MovPos == 0)   /* needed for tape.playing */
-      player->is_moving = FALSE;
-  }
+    if (stored_player[i].move_delay > 0)
+      stored_player[i].move_delay--;
 
-  if (tape.recording && num_stored_actions >= MAX_PLAYERS)
-  {
-    printf("::: player %d recorded [%d]\n", player->index_nr, FrameCounter);
+    /* due to bugs in previous versions, counter must count up, not down */
+    if (stored_player[i].push_delay != -1)
+      stored_player[i].push_delay++;
 
-    TapeRecordAction(stored_player_action);
-    num_stored_actions = 0;
+    if (stored_player[i].drop_delay > 0)
+      stored_player[i].drop_delay--;
   }
 }
-#endif
 
 void GameActions()
 {
-  static unsigned long action_delay = 0;
-  unsigned long action_delay_value;
+  static unsigned long game_frame_delay = 0;
+  unsigned long game_frame_delay_value;
   int magic_wall_x = 0, magic_wall_y = 0;
   int i, x, y, element, graphic;
   byte *recorded_player_action;
   byte summarized_player_action = 0;
-#if 1
   byte tape_action[MAX_PLAYERS];
-#endif
 
   if (game_status != GAME_MODE_PLAYING)
     return;
 
-  action_delay_value =
+  game_frame_delay_value =
     (tape.playing && tape.fast_forward ? FfwdFrameDelay : GameFrameDelay);
 
-  if (tape.playing && tape.index_search && !tape.pausing)
-    action_delay_value = 0;
+  if (tape.playing && tape.warp_forward && !tape.pausing)
+    game_frame_delay_value = 0;
 
   /* ---------- main game synchronization point ---------- */
 
-  WaitUntilDelayReached(&action_delay, action_delay_value);
+  WaitUntilDelayReached(&game_frame_delay, game_frame_delay_value);
 
   if (network_playing && !network_player_action_received)
   {
-    /*
-#ifdef DEBUG
-    printf("DEBUG: try to get network player actions in time\n");
-#endif
-    */
+    /* try to get network player actions in time */
 
-#if defined(PLATFORM_UNIX)
+#if defined(NETWORK_AVALIABLE)
     /* last chance to get network player actions without main loop delay */
     HandleNetworking();
 #endif
 
+    /* game was quit by network peer */
     if (game_status != GAME_MODE_PLAYING)
       return;
 
     if (!network_player_action_received)
-    {
-      /*
-#ifdef DEBUG
-      printf("DEBUG: failed to get network player actions in time\n");
-#endif
-      */
-      return;
-    }
+      return;          /* failed to get network player actions in time */
   }
 
   if (tape.pausing)
     return;
 
-#if 0
-  printf("::: getting new tape action [%d]\n", FrameCounter);
-#endif
-
   recorded_player_action = (tape.playing ? TapePlayAction() : NULL);
 
 #if 1
+  /* !!! CHECK THIS (tape.pausing is always FALSE here!) !!! */
   if (recorded_player_action == NULL && tape.pausing)
     return;
 #endif
 
-#if 0
-  printf("::: %d\n", stored_player[0].action);
-#endif
-
-#if 0
-  if (recorded_player_action != NULL)
-    for (i = 0; i < MAX_PLAYERS; i++)
-      stored_player[i].action = recorded_player_action[i];
-#endif
-
   for (i = 0; i < MAX_PLAYERS; i++)
   {
     summarized_player_action |= stored_player[i].action;
@@ -7799,7 +7599,7 @@ void GameActions()
       stored_player[i].effective_action = stored_player[i].action;
   }
 
-#if defined(PLATFORM_UNIX)
+#if defined(NETWORK_AVALIABLE)
   if (network_playing)
     SendToServer_MovePlayer(summarized_player_action);
 #endif
@@ -7807,13 +7607,10 @@ void GameActions()
   if (!options.network && !setup.team_mode)
     local_player->effective_action = summarized_player_action;
 
-#if 1
   if (recorded_player_action != NULL)
     for (i = 0; i < MAX_PLAYERS; i++)
       stored_player[i].effective_action = recorded_player_action[i];
-#endif
 
-#if 1
   for (i = 0; i < MAX_PLAYERS; i++)
   {
     tape_action[i] = stored_player[i].effective_action;
@@ -7825,7 +7622,6 @@ void GameActions()
   /* only save actions from input devices, but not programmed actions */
   if (tape.recording)
     TapeRecordAction(tape_action);
-#endif
 
   for (i = 0; i < MAX_PLAYERS; i++)
   {
@@ -7842,42 +7638,9 @@ void GameActions()
       CheckGravityMovement(&stored_player[i]);
 #endif
 
-#if 1
     /* overwrite programmed action with tape action */
     if (stored_player[i].programmed_action)
       actual_player_action = stored_player[i].programmed_action;
-#endif
-
-#if 0
-    if (stored_player[i].programmed_action)
-      printf("::: %d\n", stored_player[i].programmed_action);
-#endif
-
-    if (recorded_player_action)
-    {
-#if 0
-      if (stored_player[i].programmed_action &&
-         stored_player[i].programmed_action != recorded_player_action[i])
-       printf("::: %d: %d <-> %d\n", i,
-              stored_player[i].programmed_action, recorded_player_action[i]);
-#endif
-
-#if 0
-      actual_player_action = recorded_player_action[i];
-#endif
-    }
-
-#if 0
-    /* overwrite tape action with programmed action */
-    if (stored_player[i].programmed_action)
-      actual_player_action = stored_player[i].programmed_action;
-#endif
-
-#if 0
-    if (i == 0)
-      printf("::: action: %d: %x [%d]\n",
-            stored_player[i].MovPos, actual_player_action, FrameCounter);
-#endif
 
 #if 1
     PlayerActions(&stored_player[i], actual_player_action);
@@ -7891,25 +7654,11 @@ void GameActions()
     ScrollPlayer(&stored_player[i], SCROLL_GO_ON);
   }
 
-#if 0
-  if (tape.recording)
-    TapeRecordAction(tape_action);
-#endif
-
   network_player_action_received = FALSE;
 
   ScrollScreen(NULL, SCROLL_GO_ON);
 
-#if 0
-  FrameCounter++;
-  TimeFrames++;
-
-  for (i = 0; i < MAX_PLAYERS; i++)
-    stored_player[i].Frame++;
-#endif
-
-#if 1
-  /* for downwards compatibility, the following code emulates a fixed bug that
+  /* for backwards compatibility, the following code emulates a fixed bug that
      occured when pushing elements (causing elements that just made their last
      pushing step to already (if possible) make their first falling step in the
      same game frame, which is bad); this code is also needed to use the famous
@@ -7917,11 +7666,7 @@ void GameActions()
      used also in newer levels, but in this case the buggy pushing code is only
      affecting the "spring" element and no other elements */
 
-#if 1
   if (game.engine_version < VERSION_IDENT(2,2,0,7) || level.use_spring_bug)
-#else
-  if (game.engine_version < VERSION_IDENT(2,2,0,7))
-#endif
   {
     for (i = 0; i < MAX_PLAYERS; i++)
     {
@@ -7929,15 +7674,10 @@ void GameActions()
       int x = player->jx;
       int y = player->jy;
 
-#if 1
       if (player->active && player->is_pushing && player->is_moving &&
          IS_MOVING(x, y) &&
          (game.engine_version < VERSION_IDENT(2,2,0,7) ||
           Feld[x][y] == EL_SPRING))
-#else
-      if (player->active && player->is_pushing && player->is_moving &&
-         IS_MOVING(x, y))
-#endif
       {
        ContinueMoving(x, y);
 
@@ -7949,12 +7689,19 @@ void GameActions()
       }
     }
   }
-#endif
 
   for (y = 0; y < lev_fieldy; y++) for (x = 0; x < lev_fieldx; x++)
   {
-    Changed[x][y] = CE_BITMASK_DEFAULT;
-    ChangeEvent[x][y] = CE_BITMASK_DEFAULT;
+    Changed[x][y] = FALSE;
+    ChangeEvent[x][y] = -1;
+
+    /* this must be handled before main playfield loop */
+    if (Feld[x][y] == EL_PLAYER_IS_LEAVING)
+    {
+      MovDelay[x][y]--;
+      if (MovDelay[x][y] <= 0)
+       RemoveField(x, y);
+    }
 
 #if DEBUG
     if (ChangePage[x][y] != -1 && ChangeDelay[x][y] != 1)
@@ -7971,10 +7718,11 @@ void GameActions()
       WasJustMoving[x][y]--;
     if (WasJustFalling[x][y] > 0)
       WasJustFalling[x][y]--;
+    if (CheckCollision[x][y] > 0)
+      CheckCollision[x][y]--;
 
     GfxFrame[x][y]++;
 
-#if 1
     /* reset finished pushing action (not done in ContinueMoving() to allow
        continous pushing animation for elements with zero push delay) */
     if (GfxAction[x][y] == ACTION_PUSHING && !IS_MOVING(x, y))
@@ -7982,7 +7730,6 @@ void GameActions()
       ResetGfxAnimation(x, y);
       DrawLevelField(x, y);
     }
-#endif
 
 #if DEBUG
     if (IS_BLOCKED(x, y))
@@ -8004,20 +7751,7 @@ void GameActions()
   for (y = 0; y < lev_fieldy; y++) for (x = 0; x < lev_fieldx; x++)
   {
     element = Feld[x][y];
-#if 1
     graphic = el_act_dir2img(element, GfxAction[x][y], GfxDir[x][y]);
-#else
-    graphic = el2img(element);
-#endif
-
-#if 0
-    if (element == -1)
-    {
-      printf("::: %d,%d: %d [%d]\n", x, y, element, FrameCounter);
-
-      element = graphic = 0;
-    }
-#endif
 
     if (graphic_info[graphic].anim_global_sync)
       GfxFrame[x][y] = FrameCounter;
@@ -8028,9 +7762,7 @@ void GameActions()
 
     SetRandomAnimationValue(x, y);
 
-#if 1
     PlayLevelSoundActionIfLoop(x, y, GfxAction[x][y]);
-#endif
 
     if (IS_INACTIVE(element))
     {
@@ -8040,64 +7772,42 @@ void GameActions()
       continue;
     }
 
-#if 1
     /* this may take place after moving, so 'element' may have changed */
-#if 0
-    if (IS_CHANGING(x, y))
-#else
     if (IS_CHANGING(x, y) &&
        (game.engine_version < VERSION_IDENT(3,0,7,1) || !Stop[x][y]))
-#endif
     {
+      int page = element_info[element].event_page_nr[CE_DELAY];
 #if 0
-      ChangeElement(x, y, ChangePage[x][y] != -1 ? ChangePage[x][y] :
-                   element_info[element].event_page_nr[CE_DELAY]);
+      ChangeElement(x, y, ChangePage[x][y] != -1 ? ChangePage[x][y] : page);
 #else
-      ChangeElement(x, y, element_info[element].event_page_nr[CE_DELAY]);
+
+#if 0
+      printf("::: ChangeDelay == %d\n", ChangeDelay[x][y]);
+#endif
+
+      if (CAN_CHANGE(element))
+       ChangeElement(x, y, page);
+
+      if (HAS_ACTION(element) && ChangeDelay[x][y] == 0)
+       ExecuteCustomElementAction(x, y, element, page);
 #endif
 
       element = Feld[x][y];
       graphic = el_act_dir2img(element, GfxAction[x][y], GfxDir[x][y]);
     }
-#endif
 
     if (!IS_MOVING(x, y) && (CAN_FALL(element) || CAN_MOVE(element)))
     {
       StartMoving(x, y);
 
-#if 1
       element = Feld[x][y];
       graphic = el_act_dir2img(element, GfxAction[x][y], GfxDir[x][y]);
-#if 0
-      if (element == EL_MOLE)
-       printf("::: %d, %d, %d [%d]\n",
-              IS_ANIMATED(graphic), IS_MOVING(x, y), Stop[x][y],
-              GfxAction[x][y]);
-#endif
-#if 0
-      if (element == EL_YAMYAM)
-       printf("::: %d, %d, %d\n",
-              IS_ANIMATED(graphic), IS_MOVING(x, y), Stop[x][y]);
-#endif
-#endif
 
       if (IS_ANIMATED(graphic) &&
          !IS_MOVING(x, y) &&
          !Stop[x][y])
-      {
        DrawLevelGraphicAnimationIfNeeded(x, y, graphic);
 
-#if 0
-       if (element == EL_BUG)
-         printf("::: %d, %d\n", graphic, GfxFrame[x][y]);
-#endif
-
-#if 0
-       if (element == EL_MOLE)
-         printf("::: %d, %d\n", graphic, GfxFrame[x][y]);
-#endif
-      }
-
       if (IS_GEM(element) || element == EL_SP_INFOTRON)
        EdelsteinFunkeln(x, y);
     }
@@ -8115,10 +7825,6 @@ void GameActions()
       ContinueMoving(x, y);
     else if (IS_ACTIVE_BOMB(element))
       CheckDynamite(x, y);
-#if 0
-    else if (element == EL_EXPLOSION && !game.explosions_delayed)
-      Explode(x, y, ExplodePhase[x][y], EX_TYPE_NORMAL);
-#endif
     else if (element == EL_AMOEBA_GROWING)
       AmoebeWaechst(x, y);
     else if (element == EL_AMOEBA_SHRINKING)
@@ -8144,21 +7850,11 @@ void GameActions()
       MauerAbleger(x, y);
     else if (element == EL_FLAMES)
       CheckForDragon(x, y);
-#if 0
-    else if (IS_AUTO_CHANGING(element))
-      ChangeElement(x, y);
-#endif
     else if (element == EL_EXPLOSION)
       ;        /* drawing of correct explosion animation is handled separately */
     else if (IS_ANIMATED(graphic) && !IS_CHANGING(x, y))
       DrawLevelGraphicAnimationIfNeeded(x, y, graphic);
 
-#if 0
-    /* this may take place after moving, so 'element' may have changed */
-    if (IS_AUTO_CHANGING(Feld[x][y]))
-      ChangeElement(x, y);
-#endif
-
     if (IS_BELT_ACTIVE(element))
       PlayLevelSoundAction(x, y, ACTION_ACTIVE);
 
@@ -8183,27 +7879,19 @@ void GameActions()
 
 #if USE_NEW_AMOEBA_CODE
   /* new experimental amoeba growth stuff */
-#if 1
   if (!(FrameCounter % 8))
-#endif
   {
     static unsigned long random = 1684108901;
 
     for (i = 0; i < level.amoeba_speed * 28 / 8; i++)
     {
-#if 0
-      x = (random >> 10) % lev_fieldx;
-      y = (random >> 20) % lev_fieldy;
-#else
       x = RND(lev_fieldx);
       y = RND(lev_fieldy);
-#endif
       element = Feld[x][y];
 
-      /* !!! extend EL_SAND to anything diggable (but maybe not SP_BASE) !!! */
       if (!IS_PLAYER(x,y) &&
          (element == EL_EMPTY ||
-          element == EL_SAND ||
+          CAN_GROW_INTO(element) ||
           element == EL_QUICKSAND_EMPTY ||
           element == EL_ACID_SPLASH_LEFT ||
           element == EL_ACID_SPLASH_RIGHT))
@@ -8317,22 +8005,22 @@ void GameActions()
     TimeFrames = 0;
     TapeTime++;
 
-    if (!level.use_step_counter)
+    for (i = 0; i < MAX_PLAYERS; i++)
     {
-      TimePlayed++;
+      struct PlayerInfo *player = &stored_player[i];
 
-      for (i = 0; i < MAX_PLAYERS; i++)
+      if (SHIELD_ON(player))
       {
-       struct PlayerInfo *player = &stored_player[i];
-
-       if (SHIELD_ON(player))
-       {
-         player->shield_normal_time_left--;
+       player->shield_normal_time_left--;
 
-         if (player->shield_deadly_time_left > 0)
-           player->shield_deadly_time_left--;
-       }
+       if (player->shield_deadly_time_left > 0)
+         player->shield_deadly_time_left--;
       }
+    }
+
+    if (!level.use_step_counter)
+    {
+      TimePlayed++;
 
       if (TimeLeft > 0)
       {
@@ -8345,7 +8033,7 @@ void GameActions()
 
        if (!TimeLeft && setup.time_limit)
          for (i = 0; i < MAX_PLAYERS; i++)
-           KillHero(&stored_player[i]);
+           KillPlayer(&stored_player[i]);
       }
       else if (level.time == 0 && !AllPlayersGone) /* level w/o time limit */
        DrawGameValue_Time(TimePlayed);
@@ -8377,44 +8065,18 @@ void GameActions()
     redraw_mask |= REDRAW_FPS;
   }
 
-#if 0
-  if (stored_player[0].jx != stored_player[0].last_jx ||
-      stored_player[0].jy != stored_player[0].last_jy)
-    printf("::: %d, %d, %d, %d, %d\n",
-          stored_player[0].MovDir,
-          stored_player[0].MovPos,
-          stored_player[0].GfxPos,
-          stored_player[0].Frame,
-          stored_player[0].StepFrame);
-#endif
-
-#if 1
-  FrameCounter++;
-  TimeFrames++;
-
-  for (i = 0; i < MAX_PLAYERS; i++)
-  {
-    int move_frames =
-      MOVE_DELAY_NORMAL_SPEED /  stored_player[i].move_delay_value;
-
-    stored_player[i].Frame += move_frames;
-
-    if (stored_player[i].MovPos != 0)
-      stored_player[i].StepFrame += move_frames;
-
-    if (stored_player[i].drop_delay > 0)
-      stored_player[i].drop_delay--;
-  }
-#endif
+  AdvanceFrameAndPlayerCounters(-1);   /* advance counters for all players */
 
-#if 1
   if (local_player->show_envelope != 0 && local_player->MovPos == 0)
   {
     ShowEnvelope(local_player->show_envelope - EL_ENVELOPE_1);
 
     local_player->show_envelope = 0;
   }
-#endif
+
+  /* use random number generator in every frame to make it less predictable */
+  if (game.engine_version >= VERSION_IDENT(3,1,1,0))
+    RND(1);
 }
 
 static boolean AllPlayersInSight(struct PlayerInfo *player, int x, int y)
@@ -8486,118 +8148,71 @@ void ScrollLevel(int dx, int dy)
   redraw_mask |= REDRAW_FIELD;
 }
 
-static boolean canEnterSupaplexPort(int x, int y, int dx, int dy)
+static boolean canFallDown(struct PlayerInfo *player)
 {
-  int nextx = x + dx, nexty = y + dy;
+  int jx = player->jx, jy = player->jy;
+
+  return (IN_LEV_FIELD(jx, jy + 1) &&
+         (IS_FREE(jx, jy + 1) ||
+          (Feld[jx][jy + 1] == EL_ACID && player->can_fall_into_acid)) &&
+         IS_WALKABLE_FROM(Feld[jx][jy], MV_DOWN) &&
+         !IS_WALKABLE_INSIDE(Feld[jx][jy]));
+}
+
+static boolean canPassField(int x, int y, int move_dir)
+{
+  int opposite_dir = MV_DIR_OPPOSITE(move_dir);
+  int dx = (move_dir & MV_LEFT ? -1 : move_dir & MV_RIGHT ? +1 : 0);
+  int dy = (move_dir & MV_UP   ? -1 : move_dir & MV_DOWN  ? +1 : 0);
+  int nextx = x + dx;
+  int nexty = y + dy;
   int element = Feld[x][y];
 
-  if ((dx == -1 &&
-       element != EL_SP_PORT_LEFT &&
-       element != EL_SP_GRAVITY_PORT_LEFT &&
-       element != EL_SP_PORT_HORIZONTAL &&
-       element != EL_SP_PORT_ANY) ||
-      (dx == +1 &&
-       element != EL_SP_PORT_RIGHT &&
-       element != EL_SP_GRAVITY_PORT_RIGHT &&
-       element != EL_SP_PORT_HORIZONTAL &&
-       element != EL_SP_PORT_ANY) ||
-      (dy == -1 &&
-       element != EL_SP_PORT_UP &&
-       element != EL_SP_GRAVITY_PORT_UP &&
-       element != EL_SP_PORT_VERTICAL &&
-       element != EL_SP_PORT_ANY) ||
-      (dy == +1 &&
-       element != EL_SP_PORT_DOWN &&
-       element != EL_SP_GRAVITY_PORT_DOWN &&
-       element != EL_SP_PORT_VERTICAL &&
-       element != EL_SP_PORT_ANY) ||
-      !IN_LEV_FIELD(nextx, nexty) ||
-      !IS_FREE(nextx, nexty))
-    return FALSE;
+  return (IS_PASSABLE_FROM(element, opposite_dir) &&
+         !CAN_MOVE(element) &&
+         IN_LEV_FIELD(nextx, nexty) && !IS_PLAYER(nextx, nexty) &&
+         IS_WALKABLE_FROM(Feld[nextx][nexty], move_dir) &&
+         (level.can_pass_to_walkable || IS_FREE(nextx, nexty)));
+}
 
-  return TRUE;
+static boolean canMoveToValidFieldWithGravity(int x, int y, int move_dir)
+{
+  int opposite_dir = MV_DIR_OPPOSITE(move_dir);
+  int dx = (move_dir & MV_LEFT ? -1 : move_dir & MV_RIGHT ? +1 : 0);
+  int dy = (move_dir & MV_UP   ? -1 : move_dir & MV_DOWN  ? +1 : 0);
+  int newx = x + dx;
+  int newy = y + dy;
+
+  return (IN_LEV_FIELD(newx, newy) && !IS_FREE_OR_PLAYER(newx, newy) &&
+         IS_GRAVITY_REACHABLE(Feld[newx][newy]) &&
+         (IS_DIGGABLE(Feld[newx][newy]) ||
+          IS_WALKABLE_FROM(Feld[newx][newy], opposite_dir) ||
+          canPassField(newx, newy, move_dir)));
 }
 
 static void CheckGravityMovement(struct PlayerInfo *player)
 {
   if (game.gravity && !player->programmed_action)
   {
-#if 1
     int move_dir_horizontal = player->effective_action & MV_HORIZONTAL;
     int move_dir_vertical   = player->effective_action & MV_VERTICAL;
-#else
-    int move_dir_horizontal = player->action & MV_HORIZONTAL;
-    int move_dir_vertical   = player->action & MV_VERTICAL;
-#endif
-    int move_dir =
-      (player->last_move_dir & MV_HORIZONTAL ?
-       (move_dir_vertical ? move_dir_vertical : move_dir_horizontal) :
-       (move_dir_horizontal ? move_dir_horizontal : move_dir_vertical));
-    int jx = player->jx, jy = player->jy;
-    int dx = (move_dir & MV_LEFT ? -1 : move_dir & MV_RIGHT ? +1 : 0);
-    int dy = (move_dir & MV_UP ? -1 : move_dir & MV_DOWN ? +1 : 0);
-    int new_jx = jx + dx, new_jy = jy + dy;
-#if 1
     boolean player_is_snapping = player->effective_action & JOY_BUTTON_1;
-#else
-    boolean player_is_snapping = player->action & JOY_BUTTON_1;
-#endif
-#if 1
-    boolean player_can_fall_down =
-      (IN_LEV_FIELD(jx, jy + 1) &&
-       (IS_FREE(jx, jy + 1) ||
-       (Feld[jx][jy + 1] == EL_ACID && player->can_fall_into_acid)));
-#else
-    boolean player_can_fall_down =
-      (IN_LEV_FIELD(jx, jy + 1) &&
-       (IS_FREE(jx, jy + 1)));
-#endif
+    int jx = player->jx, jy = player->jy;
     boolean player_is_moving_to_valid_field =
-      (
-#if 1
-       !player_is_snapping &&
-#endif
-       IN_LEV_FIELD(new_jx, new_jy) &&
-       (Feld[new_jx][new_jy] == EL_SP_BASE ||
-       Feld[new_jx][new_jy] == EL_SAND ||
-       (IS_SP_PORT(Feld[new_jx][new_jy]) &&
-        canEnterSupaplexPort(new_jx, new_jy, dx, dy))));
-    /* !!! extend EL_SAND to anything diggable !!! */
-
-    boolean player_is_standing_on_valid_field =
-      (IS_WALKABLE_INSIDE(Feld[jx][jy]) ||
-       (IS_WALKABLE(Feld[jx][jy]) &&
-       !(element_info[Feld[jx][jy]].access_direction & MV_DOWN)));
-
-#if 0
-    printf("::: checking gravity NOW [%d, %d, %d] [%d] [%d / %d] ...\n",
-          player_can_fall_down,
-          player_is_standing_on_valid_field,
-          player_is_moving_to_valid_field,
-          (player_is_moving_to_valid_field ? Feld[new_jx][new_jy] : -1),
-          player->effective_action,
-          player->can_fall_into_acid);
-#endif
+      (!player_is_snapping &&
+       (canMoveToValidFieldWithGravity(jx, jy, move_dir_horizontal) ||
+       canMoveToValidFieldWithGravity(jx, jy, move_dir_vertical)));
+    boolean player_can_fall_down = canFallDown(player);
 
     if (player_can_fall_down &&
-       !player_is_standing_on_valid_field &&
        !player_is_moving_to_valid_field)
-    {
-#if 0
-      printf("::: setting programmed_action to MV_DOWN [%d,%d - %d] ...\n",
-            jx, jy, FrameCounter);
-#endif
-
       player->programmed_action = MV_DOWN;
-    }
   }
 }
 
 static void CheckGravityMovementWhenNotMoving(struct PlayerInfo *player)
 {
-#if 1
   return CheckGravityMovement(player);
-#endif
 
   if (game.gravity && !player->programmed_action)
   {
@@ -8624,22 +8239,6 @@ static void CheckGravityMovementWhenNotMoving(struct PlayerInfo *player)
 boolean MovePlayerOneStep(struct PlayerInfo *player,
                          int dx, int dy, int real_dx, int real_dy)
 {
-#if 0
-  static int trigger_sides[4][2] =
-  {
-    /* enter side        leave side */
-    { CH_SIDE_RIGHT,   CH_SIDE_LEFT    },      /* moving left  */
-    { CH_SIDE_LEFT,    CH_SIDE_RIGHT   },      /* moving right */
-    { CH_SIDE_BOTTOM,  CH_SIDE_TOP     },      /* moving up    */
-    { CH_SIDE_TOP,     CH_SIDE_BOTTOM  }       /* moving down  */
-  };
-  int move_direction = (dx == -1 ? MV_LEFT :
-                       dx == +1 ? MV_RIGHT :
-                       dy == -1 ? MV_UP :
-                       dy == +1 ? MV_DOWN : MV_NO_MOVING);
-  int enter_side = trigger_sides[MV_DIR_BIT(move_direction)][0];
-  int leave_side = trigger_sides[MV_DIR_BIT(move_direction)][1];
-#endif
   int jx = player->jx, jy = player->jy;
   int new_jx = jx + dx, new_jy = jy + dy;
   int element;
@@ -8659,11 +8258,7 @@ boolean MovePlayerOneStep(struct PlayerInfo *player,
   if (!options.network && !AllPlayersInSight(player, new_jx, new_jy))
     return MF_NO_ACTION;
 
-#if 0
-  element = MovingOrBlocked2Element(new_jx, new_jy);
-#else
   element = MovingOrBlocked2ElementIfNotLeaving(new_jx, new_jy);
-#endif
 
   if (DONT_RUN_INTO(element))
   {
@@ -8674,10 +8269,10 @@ boolean MovePlayerOneStep(struct PlayerInfo *player,
       InitMovingField(jx, jy, MV_DOWN);
       Store[jx][jy] = EL_ACID;
       ContinueMoving(jx, jy);
-      BuryHero(player);
+      BuryPlayer(player);
     }
     else
-      TestIfHeroRunsIntoBadThing(jx, jy, player->MovDir);
+      TestIfPlayerRunsIntoBadThing(jx, jy, player->MovDir);
 
     return MF_MOVING;
   }
@@ -8688,7 +8283,7 @@ boolean MovePlayerOneStep(struct PlayerInfo *player,
 
   /* check if DigField() has caused relocation of the player */
   if (player->jx != jx || player->jy != jy)
-    return MF_NO_ACTION;
+    return MF_NO_ACTION;       /* <-- !!! CHECK THIS [-> MF_ACTION ?] !!! */
 
   StorePlayer[jx][jy] = 0;
   player->last_jx = jx;
@@ -8702,29 +8297,10 @@ boolean MovePlayerOneStep(struct PlayerInfo *player,
 
   player->step_counter++;
 
-  player->drop_delay = 0;
-
   PlayerVisit[jx][jy] = FrameCounter;
 
   ScrollPlayer(player, SCROLL_INIT);
 
-#if 0
-  if (IS_CUSTOM_ELEMENT(Feld[jx][jy]))
-  {
-    CheckTriggeredElementChangeSide(jx, jy, Feld[jx][jy], CE_OTHER_GETS_LEFT,
-                                   leave_side);
-    CheckElementChangeSide(jx, jy, Feld[jx][jy], CE_LEFT_BY_PLAYER,leave_side);
-  }
-
-  if (IS_CUSTOM_ELEMENT(Feld[new_jx][new_jy]))
-  {
-    CheckTriggeredElementChangeSide(new_jx, new_jy, Feld[new_jx][new_jy],
-                                   CE_OTHER_GETS_ENTERED, enter_side);
-    CheckElementChangeSide(new_jx, new_jy, Feld[new_jx][new_jy],
-                          CE_ENTERED_BY_PLAYER, enter_side);
-  }
-#endif
-
   return MF_MOVING;
 }
 
@@ -8734,7 +8310,6 @@ boolean MovePlayer(struct PlayerInfo *player, int dx, int dy)
   int old_jx = jx, old_jy = jy;
   int moved = MF_NO_ACTION;
 
-#if 1
   if (!player->active)
     return FALSE;
 
@@ -8751,27 +8326,14 @@ boolean MovePlayer(struct PlayerInfo *player, int dx, int dy)
 
     return FALSE;
   }
-#else
-  if (!player->active || (!dx && !dy))
-    return FALSE;
-#endif
 
-#if 0
-  if (!FrameReached(&player->move_delay, player->move_delay_value) &&
-      !tape.playing)
+  if (player->move_delay > 0)
     return FALSE;
-#else
 
-#if 1
-  if (!FrameReached(&player->move_delay, player->move_delay_value))
-    return FALSE;
-#else
-  if (!FrameReached(&player->move_delay, player->move_delay_value) &&
-      !(tape.playing && tape.file_version < FILE_VERSION_2_0))
-    return FALSE;
-#endif
+  player->move_delay = -1;             /* set to "uninitialized" value */
 
-#endif
+  /* store if player is automatically moved to next field */
+  player->is_auto_moving = (player->programmed_action != MV_NO_MOVING);
 
   /* remove the last programmed player action */
   player->programmed_action = 0;
@@ -8795,7 +8357,9 @@ boolean MovePlayer(struct PlayerInfo *player, int dx, int dy)
     {
       ScrollPlayer(player, SCROLL_GO_ON);
       ScrollScreen(NULL, SCROLL_GO_ON);
-      FrameCounter++;
+
+      AdvanceFrameAndPlayerCounters(player->index_nr);
+
       DrawAllPlayers();
       BackToFront();
     }
@@ -8886,15 +8450,6 @@ boolean MovePlayer(struct PlayerInfo *player, int dx, int dy)
     }
   }
 
-#if 0
-#if 1
-  InitPlayerGfxAnimation(player, ACTION_DEFAULT);
-#else
-  if (!(moved & MF_MOVING) && !player->is_pushing)
-    player->Frame = 0;
-#endif
-#endif
-
   player->StepFrame = 0;
 
   if (moved & MF_MOVING)
@@ -8908,74 +8463,36 @@ boolean MovePlayer(struct PlayerInfo *player, int dx, int dy)
 
     player->last_move_dir = player->MovDir;
     player->is_moving = TRUE;
-#if 1
     player->is_snapping = FALSE;
-#endif
-
-#if 1
     player->is_switching = FALSE;
-#endif
-
     player->is_dropping = FALSE;
-
-
-#if 0
-    /* !!! ENABLE THIS FOR OLD VERSIONS !!! */
-    {
-      static int trigger_sides[4][2] =
-      {
-       /* enter side           leave side */
-       { CH_SIDE_RIGHT,        CH_SIDE_LEFT    },      /* moving left  */
-       { CH_SIDE_LEFT,         CH_SIDE_RIGHT   },      /* moving right */
-       { CH_SIDE_BOTTOM,       CH_SIDE_TOP     },      /* moving up    */
-       { CH_SIDE_TOP,          CH_SIDE_BOTTOM  }       /* moving down  */
-      };
-      int move_direction = player->MovDir;
-      int enter_side = trigger_sides[MV_DIR_BIT(move_direction)][0];
-      int leave_side = trigger_sides[MV_DIR_BIT(move_direction)][1];
-
-#if 1
-      CheckTriggeredElementChangePlayer(old_jx, old_jy, Feld[old_jx][old_jy],
-                                       CE_OTHER_GETS_LEFT,
-                                       player->index_bit, leave_side);
-
-      if (IS_CUSTOM_ELEMENT(Feld[old_jx][old_jy]))
-       CheckElementChangePlayer(old_jx, old_jy, Feld[old_jx][old_jy],
-                                CE_LEFT_BY_PLAYER,
-                                player->index_bit, leave_side);
-
-      CheckTriggeredElementChangePlayer(jx, jy, Feld[jx][jy],
-                                       CE_OTHER_GETS_ENTERED,
-                                       player->index_bit, enter_side);
-
-      if (IS_CUSTOM_ELEMENT(Feld[jx][jy]))
-       CheckElementChangePlayer(jx, jy, Feld[jx][jy], CE_ENTERED_BY_PLAYER,
-                                player->index_bit, enter_side);
-#endif
-
-    }
-#endif
-
-
   }
   else
   {
     CheckGravityMovementWhenNotMoving(player);
 
-    /*
-    player->last_move_dir = MV_NO_MOVING;
-    */
     player->is_moving = FALSE;
+
+    /* at this point, the player is allowed to move, but cannot move right now
+       (e.g. because of something blocking the way) -- ensure that the player
+       is also allowed to move in the next frame (in old versions before 3.1.1,
+       the player was forced to wait again for eight frames before next try) */
+
+    if (game.engine_version >= VERSION_IDENT(3,1,1,0))
+      player->move_delay = 0;  /* allow direct movement in the next frame */
   }
 
+  if (player->move_delay == -1)                /* not yet initialized by DigField() */
+    player->move_delay = player->move_delay_value;
+
   if (game.engine_version < VERSION_IDENT(3,0,7,0))
   {
-    TestIfHeroTouchesBadThing(jx, jy);
+    TestIfPlayerTouchesBadThing(jx, jy);
     TestIfPlayerTouchesCustomElement(jx, jy);
   }
 
   if (!player->active)
-    RemoveHero(player);
+    RemovePlayer(player);
 
   return moved;
 }
@@ -8986,44 +8503,86 @@ void ScrollPlayer(struct PlayerInfo *player, int mode)
   int last_jx = player->last_jx, last_jy = player->last_jy;
   int move_stepsize = TILEX / player->move_delay_value;
 
-  if (!player->active || !player->MovPos)
+#if USE_NEW_PLAYER_SPEED
+  if (!player->active)
+    return;
+
+  if (player->MovPos == 0 && mode == SCROLL_GO_ON)     /* player not moving */
+    return;
+#else
+  if (!player->active || player->MovPos == 0)
     return;
+#endif
 
   if (mode == SCROLL_INIT)
   {
     player->actual_frame_counter = FrameCounter;
     player->GfxPos = move_stepsize * (player->MovPos / move_stepsize);
 
-    if (Feld[last_jx][last_jy] == EL_EMPTY)
-      Feld[last_jx][last_jy] = EL_PLAYER_IS_LEAVING;
+    if ((player->block_last_field || player->block_delay_adjustment > 0) &&
+       Feld[last_jx][last_jy] == EL_EMPTY)
+    {
+      int last_field_block_delay = 0;  /* start with no blocking at all */
+      int block_delay_adjustment = player->block_delay_adjustment;
 
-#if 0
-    DrawPlayer(player);
-#endif
+      /* if player blocks last field, add delay for exactly one move */
+      if (player->block_last_field)
+      {
+       last_field_block_delay += player->move_delay_value;
+
+       /* when blocking enabled, prevent moving up despite gravity */
+       if (game.gravity && player->MovDir == MV_UP)
+         block_delay_adjustment = -1;
+      }
+
+      /* add block delay adjustment (also possible when not blocking) */
+      last_field_block_delay += block_delay_adjustment;
+
+      Feld[last_jx][last_jy] = EL_PLAYER_IS_LEAVING;
+      MovDelay[last_jx][last_jy] = last_field_block_delay + 1;
+    }
 
+#if USE_NEW_PLAYER_SPEED
+    if (player->MovPos != 0)   /* player has not yet reached destination */
+      return;
+#else
     return;
+#endif
   }
   else if (!FrameReached(&player->actual_frame_counter, 1))
     return;
 
+#if 0
+    printf("::: player->MovPos: %d -> %d\n",
+          player->MovPos,
+          player->MovPos + (player->MovPos > 0 ? -1 : 1) * move_stepsize);
+#endif
+
+#if USE_NEW_PLAYER_SPEED
+    if (player->MovPos != 0)
+    {
+      player->MovPos += (player->MovPos > 0 ? -1 : 1) * move_stepsize;
+      player->GfxPos = move_stepsize * (player->MovPos / move_stepsize);
+
+      /* before DrawPlayer() to draw correct player graphic for this case */
+      if (player->MovPos == 0)
+       CheckGravityMovement(player);
+    }
+#else
   player->MovPos += (player->MovPos > 0 ? -1 : 1) * move_stepsize;
   player->GfxPos = move_stepsize * (player->MovPos / move_stepsize);
 
-  if (!player->block_last_field &&
-      Feld[last_jx][last_jy] == EL_PLAYER_IS_LEAVING)
-    Feld[last_jx][last_jy] = EL_EMPTY;
-
   /* before DrawPlayer() to draw correct player graphic for this case */
   if (player->MovPos == 0)
     CheckGravityMovement(player);
-
-#if 0
-  DrawPlayer(player);  /* needed here only to cleanup last field */
 #endif
 
   if (player->MovPos == 0)     /* player reached destination field */
   {
-#if 1
+#if 0
+    printf("::: player reached destination field\n");
+#endif
+
     if (player->move_delay_reset_counter > 0)
     {
       player->move_delay_reset_counter--;
@@ -9037,20 +8596,6 @@ void ScrollPlayer(struct PlayerInfo *player, int mode)
        player->move_delay = 0;
       }
     }
-#else
-    if (IS_PASSABLE(Feld[last_jx][last_jy]))
-    {
-      /* continue with normal speed after quickly moving through gate */
-      HALVE_PLAYER_SPEED(player);
-
-      /* be able to make the next move without delay */
-      player->move_delay = 0;
-    }
-#endif
-
-    if (player->block_last_field &&
-       Feld[last_jx][last_jy] == EL_PLAYER_IS_LEAVING)
-      Feld[last_jx][last_jy] = EL_EMPTY;
 
     player->last_jx = jx;
     player->last_jy = jy;
@@ -9060,63 +8605,51 @@ void ScrollPlayer(struct PlayerInfo *player, int mode)
        Feld[jx][jy] == EL_SP_EXIT_OPENING)     /* <-- special case */
     {
       DrawPlayer(player);      /* needed here only to cleanup last field */
-      RemoveHero(player);
+      RemovePlayer(player);
 
       if (local_player->friends_still_needed == 0 ||
          IS_SP_ELEMENT(Feld[jx][jy]))
        player->LevelSolved = player->GameOver = TRUE;
     }
 
-#if 1
-    /* !!! ENABLE THIS FOR NEW VERSIONS !!! */
     /* this breaks one level: "machine", level 000 */
     {
-      static int trigger_sides[4][2] =
-      {
-       /* enter side           leave side */
-       { CH_SIDE_RIGHT,        CH_SIDE_LEFT    },      /* moving left  */
-       { CH_SIDE_LEFT,         CH_SIDE_RIGHT   },      /* moving right */
-       { CH_SIDE_BOTTOM,       CH_SIDE_TOP     },      /* moving up    */
-       { CH_SIDE_TOP,          CH_SIDE_BOTTOM  }       /* moving down  */
-      };
       int move_direction = player->MovDir;
-      int enter_side = trigger_sides[MV_DIR_BIT(move_direction)][0];
-      int leave_side = trigger_sides[MV_DIR_BIT(move_direction)][1];
+      int enter_side = MV_DIR_OPPOSITE(move_direction);
+      int leave_side = move_direction;
       int old_jx = last_jx;
       int old_jy = last_jy;
+      int old_element = Feld[old_jx][old_jy];
+      int new_element = Feld[jx][jy];
 
-#if 1
-      CheckTriggeredElementChangePlayer(old_jx, old_jy, Feld[old_jx][old_jy],
-                                       CE_OTHER_GETS_LEFT,
-                                       player->index_bit, leave_side);
-
-      if (IS_CUSTOM_ELEMENT(Feld[old_jx][old_jy]))
-       CheckElementChangePlayer(old_jx, old_jy, Feld[old_jx][old_jy],
-                                CE_LEFT_BY_PLAYER,
-                                player->index_bit, leave_side);
-
-      CheckTriggeredElementChangePlayer(jx, jy, Feld[jx][jy],
-                                       CE_OTHER_GETS_ENTERED,
-                                       player->index_bit, enter_side);
-
-      if (IS_CUSTOM_ELEMENT(Feld[jx][jy]))
-       CheckElementChangePlayer(jx, jy, Feld[jx][jy], CE_ENTERED_BY_PLAYER,
-                                player->index_bit, enter_side);
-#endif
+      if (IS_CUSTOM_ELEMENT(old_element))
+       CheckElementChangeByPlayer(old_jx, old_jy, old_element,
+                                  CE_LEFT_BY_PLAYER,
+                                  player->index_bit, leave_side);
+
+      CheckTriggeredElementChangeByPlayer(old_element, CE_PLAYER_LEAVES_X,
+                                         player->index_bit, leave_side);
 
+      if (IS_CUSTOM_ELEMENT(new_element))
+       CheckElementChangeByPlayer(jx, jy, new_element, CE_ENTERED_BY_PLAYER,
+                                  player->index_bit, enter_side);
+
+      CheckTriggeredElementChangeByPlayer(new_element, CE_PLAYER_ENTERS_X,
+                                         player->index_bit, enter_side);
     }
-#endif
 
     if (game.engine_version >= VERSION_IDENT(3,0,7,0))
     {
-      TestIfHeroTouchesBadThing(jx, jy);
+      TestIfPlayerTouchesBadThing(jx, jy);
       TestIfPlayerTouchesCustomElement(jx, jy);
-#if 1
-      TestIfElementTouchesCustomElement(jx, jy);       /* for empty space */
-#endif
+
+      /* needed because pushed element has not yet reached its destination,
+        so it would trigger a change event at its previous field location */
+      if (!player->is_pushing)
+       TestIfElementTouchesCustomElement(jx, jy);      /* for empty space */
 
       if (!player->active)
-       RemoveHero(player);
+       RemovePlayer(player);
     }
 
     if (level.use_step_counter)
@@ -9125,19 +8658,6 @@ void ScrollPlayer(struct PlayerInfo *player, int mode)
 
       TimePlayed++;
 
-      for (i = 0; i < MAX_PLAYERS; i++)
-      {
-       struct PlayerInfo *player = &stored_player[i];
-
-       if (SHIELD_ON(player))
-       {
-         player->shield_normal_time_left--;
-
-         if (player->shield_deadly_time_left > 0)
-           player->shield_deadly_time_left--;
-       }
-      }
-
       if (TimeLeft > 0)
       {
        TimeLeft--;
@@ -9149,7 +8669,7 @@ void ScrollPlayer(struct PlayerInfo *player, int mode)
 
        if (!TimeLeft && setup.time_limit)
          for (i = 0; i < MAX_PLAYERS; i++)
-           KillHero(&stored_player[i]);
+           KillPlayer(&stored_player[i]);
       }
       else if (level.time == 0 && !AllPlayersGone) /* level w/o time limit */
        DrawGameValue_Time(TimePlayed);
@@ -9240,11 +8760,10 @@ void TestIfPlayerTouchesCustomElement(int x, int y)
       else
        continue;               /* center and border element do not touch */
 
-      CheckTriggeredElementChangePlayer(xx, yy, border_element,
-                                       CE_OTHER_GETS_TOUCHED,
-                                       player->index_bit, border_side);
-      CheckElementChangePlayer(xx, yy, border_element, CE_TOUCHED_BY_PLAYER,
-                              player->index_bit, border_side);
+      CheckElementChangeByPlayer(xx, yy, border_element, CE_TOUCHED_BY_PLAYER,
+                                player->index_bit, border_side);
+      CheckTriggeredElementChangeByPlayer(border_element, CE_PLAYER_TOUCHES_X,
+                                         player->index_bit, border_side);
     }
     else if (IS_PLAYER(xx, yy))
     {
@@ -9256,12 +8775,10 @@ void TestIfPlayerTouchesCustomElement(int x, int y)
          continue;             /* center and border element do not touch */
       }
 
-      CheckTriggeredElementChangePlayer(x, y, center_element,
-                                       CE_OTHER_GETS_TOUCHED,
-                                       player->index_bit, center_side);
-      CheckElementChangePlayer(x, y, center_element, CE_TOUCHED_BY_PLAYER,
-                              player->index_bit, center_side);
-
+      CheckElementChangeByPlayer(x, y, center_element, CE_TOUCHED_BY_PLAYER,
+                                player->index_bit, center_side);
+      CheckTriggeredElementChangeByPlayer(center_element, CE_PLAYER_TOUCHES_X,
+                                         player->index_bit, center_side);
       break;
     }
   }
@@ -9292,10 +8809,8 @@ void TestIfElementTouchesCustomElement(int x, int y)
     MV_LEFT | MV_RIGHT
   };
   boolean change_center_element = FALSE;
-  int center_element_change_page = 0;
   int center_element = Feld[x][y];     /* should always be non-moving! */
-  int border_trigger_element;
-  int i, j;
+  int i;
 
   for (i = 0; i < NUM_DIRECTIONS; i++)
   {
@@ -9318,73 +8833,14 @@ void TestIfElementTouchesCustomElement(int x, int y)
       continue;                        /* center and border element do not touch */
 
     /* check for change of center element (but change it only once) */
-    if (IS_CUSTOM_ELEMENT(center_element) &&
-       HAS_ANY_CHANGE_EVENT(center_element, CE_OTHER_IS_TOUCHING) &&
-       !change_center_element)
-    {
-      for (j = 0; j < element_info[center_element].num_change_pages; j++)
-      {
-       struct ElementChangeInfo *change =
-         &element_info[center_element].change_page[j];
-
-       if (change->can_change &&
-           change->events & CH_EVENT_BIT(CE_OTHER_IS_TOUCHING) &&
-           change->trigger_side & border_side &&
-#if 1
-           IS_EQUAL_OR_IN_GROUP(border_element, change->trigger_element)
-#else
-           change->trigger_element == border_element
-#endif
-           )
-       {
-         change_center_element = TRUE;
-         center_element_change_page = j;
-         border_trigger_element = border_element;
-
-         break;
-       }
-      }
-    }
+    if (!change_center_element)
+      change_center_element =
+       CheckElementChangeBySide(x, y, center_element, border_element,
+                                CE_TOUCHING_X, border_side);
 
     /* check for change of border element */
-    if (IS_CUSTOM_ELEMENT(border_element) &&
-       HAS_ANY_CHANGE_EVENT(border_element, CE_OTHER_IS_TOUCHING))
-    {
-      for (j = 0; j < element_info[border_element].num_change_pages; j++)
-      {
-       struct ElementChangeInfo *change =
-         &element_info[border_element].change_page[j];
-
-       if (change->can_change &&
-           change->events & CH_EVENT_BIT(CE_OTHER_IS_TOUCHING) &&
-           change->trigger_side & center_side &&
-#if 1
-           IS_EQUAL_OR_IN_GROUP(center_element, change->trigger_element)
-#else
-           change->trigger_element == center_element
-#endif
-           )
-       {
-#if 0
-         printf("::: border_element %d, %d\n", x, y);
-#endif
-
-         CheckElementChangePage(xx, yy, border_element, center_element,
-                                CE_OTHER_IS_TOUCHING, j);
-         break;
-       }
-      }
-    }
-  }
-
-  if (change_center_element)
-  {
-#if 0
-    printf("::: center_element %d, %d\n", x, y);
-#endif
-
-    CheckElementChangePage(x, y, center_element, border_trigger_element,
-                          CE_OTHER_IS_TOUCHING, center_element_change_page);
+    CheckElementChangeBySide(xx, yy, border_element, center_element,
+                            CE_TOUCHING_X, center_side);
   }
 }
 
@@ -9395,103 +8851,40 @@ void TestIfElementHitsCustomElement(int x, int y, int direction)
   int hitx = x + dx, hity = y + dy;
   int hitting_element = Feld[x][y];
   int touched_element;
-#if 0
-  boolean object_hit = (IN_LEV_FIELD(hitx, hity) &&
-                       !IS_FREE(hitx, hity) &&
-                       (!IS_MOVING(hitx, hity) ||
-                        MovDir[hitx][hity] != direction ||
-                        ABS(MovPos[hitx][hity]) <= TILEY / 2));
-#endif
 
   if (IN_LEV_FIELD(hitx, hity) && IS_FREE(hitx, hity))
     return;
 
-#if 0
-  if (IN_LEV_FIELD(hitx, hity) && !object_hit)
-    return;
-#endif
-
   touched_element = (IN_LEV_FIELD(hitx, hity) ?
                     MovingOrBlocked2Element(hitx, hity) : EL_STEELWALL);
 
-  CheckElementChangeSide(x, y, hitting_element, touched_element,
-                        CE_HITTING_SOMETHING, direction);
-
   if (IN_LEV_FIELD(hitx, hity))
   {
     int opposite_direction = MV_DIR_OPPOSITE(direction);
     int hitting_side = direction;
     int touched_side = opposite_direction;
-#if 0
-    int touched_element = MovingOrBlocked2Element(hitx, hity);
-#endif
-#if 1
     boolean object_hit = (!IS_MOVING(hitx, hity) ||
                          MovDir[hitx][hity] != direction ||
                          ABS(MovPos[hitx][hity]) <= TILEY / 2);
 
     object_hit = TRUE;
-#endif
 
     if (object_hit)
     {
-      int i;
+      CheckElementChangeBySide(x, y, hitting_element, touched_element,
+                              CE_HITTING_X, touched_side);
 
-      CheckElementChangeSide(hitx, hity, touched_element, hitting_element,
-                            CE_HIT_BY_SOMETHING, opposite_direction);
+      CheckElementChangeBySide(hitx, hity, touched_element,
+                              hitting_element, CE_HIT_BY_X, hitting_side);
 
-      if (IS_CUSTOM_ELEMENT(hitting_element) &&
-         HAS_ANY_CHANGE_EVENT(hitting_element, CE_OTHER_IS_HITTING))
-      {
-       for (i = 0; i < element_info[hitting_element].num_change_pages; i++)
-       {
-         struct ElementChangeInfo *change =
-           &element_info[hitting_element].change_page[i];
-
-         if (change->can_change &&
-             change->events & CH_EVENT_BIT(CE_OTHER_IS_HITTING) &&
-             change->trigger_side & touched_side &&
-         
-#if 1
-             IS_EQUAL_OR_IN_GROUP(touched_element, change->trigger_element)
-#else
-             change->trigger_element == touched_element
-#endif
-             )
-         {
-           CheckElementChangePage(x, y, hitting_element, touched_element,
-                                  CE_OTHER_IS_HITTING, i);
-           break;
-         }
-       }
-      }
-
-      if (IS_CUSTOM_ELEMENT(touched_element) &&
-         HAS_ANY_CHANGE_EVENT(touched_element, CE_OTHER_GETS_HIT))
-      {
-       for (i = 0; i < element_info[touched_element].num_change_pages; i++)
-       {
-         struct ElementChangeInfo *change =
-           &element_info[touched_element].change_page[i];
-
-         if (change->can_change &&
-             change->events & CH_EVENT_BIT(CE_OTHER_GETS_HIT) &&
-             change->trigger_side & hitting_side &&
-#if 1
-             IS_EQUAL_OR_IN_GROUP(hitting_element, change->trigger_element)
-#else
-             change->trigger_element == hitting_element
-#endif
-             )
-         {
-           CheckElementChangePage(hitx, hity, touched_element,
-                                  hitting_element, CE_OTHER_GETS_HIT, i);
-           break;
-         }
-       }
-      }
+      CheckElementChangeBySide(hitx, hity, touched_element, hitting_element,
+                              CE_HIT_BY_SOMETHING, opposite_direction);
     }
   }
+
+  /* "hitting something" is also true when hitting the playfield border */
+  CheckElementChangeBySide(x, y, hitting_element, touched_element,
+                          CE_HITTING_SOMETHING, direction);
 }
 
 #if 0
@@ -9521,8 +8914,8 @@ void TestIfElementSmashesCustomElement(int x, int y, int direction)
   touched_element = (IN_LEV_FIELD(hitx, hity) ?
                     MovingOrBlocked2Element(hitx, hity) : EL_STEELWALL);
 
-  CheckElementChangeSide(x, y, hitting_element, touched_element,
-                        EP_CAN_SMASH_EVERYTHING, direction);
+  CheckElementChangeBySide(x, y, hitting_element, touched_element,
+                          EP_CAN_SMASH_EVERYTHING, direction);
 
   if (IN_LEV_FIELD(hitx, hity))
   {
@@ -9544,59 +8937,14 @@ void TestIfElementSmashesCustomElement(int x, int y, int direction)
     {
       int i;
 
-      CheckElementChangeSide(hitx, hity, touched_element, hitting_element,
-                            CE_SMASHED_BY_SOMETHING, opposite_direction);
-
-      if (IS_CUSTOM_ELEMENT(hitting_element) &&
-         HAS_ANY_CHANGE_EVENT(hitting_element, CE_OTHER_IS_SMASHING))
-      {
-       for (i = 0; i < element_info[hitting_element].num_change_pages; i++)
-       {
-         struct ElementChangeInfo *change =
-           &element_info[hitting_element].change_page[i];
-
-         if (change->can_change &&
-             change->events & CH_EVENT_BIT(CE_OTHER_IS_SMASHING) &&
-             change->trigger_side & touched_side &&
-         
-#if 1
-             IS_EQUAL_OR_IN_GROUP(touched_element, change->trigger_element)
-#else
-             change->trigger_element == touched_element
-#endif
-             )
-         {
-           CheckElementChangePage(x, y, hitting_element, touched_element,
-                                  CE_OTHER_IS_SMASHING, i);
-           break;
-         }
-       }
-      }
+      CheckElementChangeBySide(hitx, hity, touched_element, hitting_element,
+                              CE_SMASHED_BY_SOMETHING, opposite_direction);
 
-      if (IS_CUSTOM_ELEMENT(touched_element) &&
-         HAS_ANY_CHANGE_EVENT(touched_element, CE_OTHER_GETS_SMASHED))
-      {
-       for (i = 0; i < element_info[touched_element].num_change_pages; i++)
-       {
-         struct ElementChangeInfo *change =
-           &element_info[touched_element].change_page[i];
+      CheckElementChangeBySide(x, y, hitting_element, touched_element,
+                              CE_OTHER_IS_SMASHING, touched_side);
 
-         if (change->can_change &&
-             change->events & CH_EVENT_BIT(CE_OTHER_GETS_SMASHED) &&
-             change->trigger_side & hitting_side &&
-#if 1
-             IS_EQUAL_OR_IN_GROUP(hitting_element, change->trigger_element)
-#else
-             change->trigger_element == hitting_element
-#endif
-             )
-         {
-           CheckElementChangePage(hitx, hity, touched_element,
-                                  hitting_element, CE_OTHER_GETS_SMASHED, i);
-           break;
-         }
-       }
-      }
+      CheckElementChangeBySide(hitx, hity, touched_element, hitting_element,
+                              CE_OTHER_GETS_SMASHED, hitting_side);
     }
   }
 }
@@ -9605,6 +8953,7 @@ void TestIfElementSmashesCustomElement(int x, int y, int direction)
 void TestIfGoodThingHitsBadThing(int good_x, int good_y, int good_move_dir)
 {
   int i, kill_x = -1, kill_y = -1;
+  int bad_element = -1;
   static int test_xy[4][2] =
   {
     { 0, -1 },
@@ -9626,17 +8975,14 @@ void TestIfGoodThingHitsBadThing(int good_x, int good_y, int good_move_dir)
 
     test_x = good_x + test_xy[i][0];
     test_y = good_y + test_xy[i][1];
+
     if (!IN_LEV_FIELD(test_x, test_y))
       continue;
 
     test_move_dir =
       (IS_MOVING(test_x, test_y) ? MovDir[test_x][test_y] : MV_NO_MOVING);
 
-#if 0
-    test_element = Feld[test_x][test_y];
-#else
     test_element = MovingOrBlocked2ElementIfNotLeaving(test_x, test_y);
-#endif
 
     /* 1st case: good thing is moving towards DONT_RUN_INTO style bad thing;
        2nd case: DONT_TOUCH style bad thing does not move away from good thing
@@ -9646,6 +8992,8 @@ void TestIfGoodThingHitsBadThing(int good_x, int good_y, int good_move_dir)
     {
       kill_x = test_x;
       kill_y = test_y;
+      bad_element = test_element;
+
       break;
     }
   }
@@ -9656,10 +9004,11 @@ void TestIfGoodThingHitsBadThing(int good_x, int good_y, int good_move_dir)
     {
       struct PlayerInfo *player = PLAYERINFO(good_x, good_y);
 
-      if (player->shield_deadly_time_left > 0)
+      if (player->shield_deadly_time_left > 0 &&
+         !IS_INDESTRUCTIBLE(bad_element))
        Bang(kill_x, kill_y);
       else if (!PLAYER_ENEMY_PROTECTED(good_x, good_y))
-       KillHero(player);
+       KillPlayer(player);
     }
     else
       Bang(good_x, good_y);
@@ -9748,32 +9097,33 @@ void TestIfBadThingHitsGoodThing(int bad_x, int bad_y, int bad_move_dir)
     {
       struct PlayerInfo *player = PLAYERINFO(kill_x, kill_y);
 
-      if (player->shield_deadly_time_left > 0)
+      if (player->shield_deadly_time_left > 0 &&
+         !IS_INDESTRUCTIBLE(bad_element))
        Bang(bad_x, bad_y);
       else if (!PLAYER_ENEMY_PROTECTED(kill_x, kill_y))
-       KillHero(player);
+       KillPlayer(player);
     }
     else
       Bang(kill_x, kill_y);
   }
 }
 
-void TestIfHeroTouchesBadThing(int x, int y)
+void TestIfPlayerTouchesBadThing(int x, int y)
 {
   TestIfGoodThingHitsBadThing(x, y, MV_NO_MOVING);
 }
 
-void TestIfHeroRunsIntoBadThing(int x, int y, int move_dir)
+void TestIfPlayerRunsIntoBadThing(int x, int y, int move_dir)
 {
   TestIfGoodThingHitsBadThing(x, y, move_dir);
 }
 
-void TestIfBadThingTouchesHero(int x, int y)
+void TestIfBadThingTouchesPlayer(int x, int y)
 {
   TestIfBadThingHitsGoodThing(x, y, MV_NO_MOVING);
 }
 
-void TestIfBadThingRunsIntoHero(int x, int y, int move_dir)
+void TestIfBadThingRunsIntoPlayer(int x, int y, int move_dir)
 {
   TestIfBadThingHitsGoodThing(x, y, move_dir);
 }
@@ -9822,7 +9172,7 @@ void TestIfBadThingTouchesOtherBadThing(int bad_x, int bad_y)
     Bang(bad_x, bad_y);
 }
 
-void KillHero(struct PlayerInfo *player)
+void KillPlayer(struct PlayerInfo *player)
 {
   int jx = player->jx, jy = player->jy;
 
@@ -9837,40 +9187,36 @@ void KillHero(struct PlayerInfo *player)
   player->shield_deadly_time_left = 0;
 
   Bang(jx, jy);
-  BuryHero(player);
+  BuryPlayer(player);
 }
 
-static void KillHeroUnlessEnemyProtected(int x, int y)
+static void KillPlayerUnlessEnemyProtected(int x, int y)
 {
   if (!PLAYER_ENEMY_PROTECTED(x, y))
-    KillHero(PLAYERINFO(x, y));
+    KillPlayer(PLAYERINFO(x, y));
 }
 
-static void KillHeroUnlessExplosionProtected(int x, int y)
+static void KillPlayerUnlessExplosionProtected(int x, int y)
 {
   if (!PLAYER_EXPLOSION_PROTECTED(x, y))
-    KillHero(PLAYERINFO(x, y));
+    KillPlayer(PLAYERINFO(x, y));
 }
 
-void BuryHero(struct PlayerInfo *player)
+void BuryPlayer(struct PlayerInfo *player)
 {
   int jx = player->jx, jy = player->jy;
 
   if (!player->active)
     return;
 
-#if 1
   PlayLevelSoundElementAction(jx, jy, player->element_nr, ACTION_DYING);
-#else
-  PlayLevelSound(jx, jy, SND_CLASS_PLAYER_DYING);
-#endif
   PlayLevelSound(jx, jy, SND_GAME_LOSING);
 
   player->GameOver = TRUE;
-  RemoveHero(player);
+  RemovePlayer(player);
 }
 
-void RemoveHero(struct PlayerInfo *player)
+void RemovePlayer(struct PlayerInfo *player)
 {
   int jx = player->jx, jy = player->jy;
   int i, found = FALSE;
@@ -9881,6 +9227,9 @@ void RemoveHero(struct PlayerInfo *player)
   if (!ExplodeField[jx][jy])
     StorePlayer[jx][jy] = 0;
 
+  if (player->is_moving)
+    DrawLevelField(player->last_jx, player->last_jy);
+
   for (i = 0; i < MAX_PLAYERS; i++)
     if (stored_player[i].active)
       found = TRUE;
@@ -9933,16 +9282,8 @@ int DigField(struct PlayerInfo *player,
             int oldx, int oldy, int x, int y,
             int real_dx, int real_dy, int mode)
 {
-  static int trigger_sides[4] =
-  {
-    CH_SIDE_RIGHT,     /* moving left  */
-    CH_SIDE_LEFT,      /* moving right */
-    CH_SIDE_BOTTOM,    /* moving up    */
-    CH_SIDE_TOP,       /* moving down  */
-  };
-#if 0
-  boolean use_spring_bug = (game.engine_version < VERSION_IDENT(2,2,0,0));
-#endif
+  boolean is_player = (IS_PLAYER(oldx, oldy) || mode != DF_DIG);
+  boolean player_was_pushing = player->is_pushing;
   int jx = oldx, jy = oldy;
   int dx = x - jx, dy = y - jy;
   int nextx = x + dx, nexty = y + dy;
@@ -9951,683 +9292,520 @@ int DigField(struct PlayerInfo *player,
                        dy == -1 ? MV_UP :
                        dy == +1 ? MV_DOWN : MV_NO_MOVING);
   int opposite_direction = MV_DIR_OPPOSITE(move_direction);
-  int dig_side = trigger_sides[MV_DIR_BIT(move_direction)];
+  int dig_side = MV_DIR_OPPOSITE(move_direction);
   int old_element = Feld[jx][jy];
   int element;
+  int collect_count;
 
-  if (player->MovPos == 0)
+  if (is_player)               /* function can also be called by EL_PENGUIN */
   {
-    player->is_digging = FALSE;
-    player->is_collecting = FALSE;
-  }
+    if (player->MovPos == 0)
+    {
+      player->is_digging = FALSE;
+      player->is_collecting = FALSE;
+    }
 
-  if (player->MovPos == 0)     /* last pushing move finished */
-    player->is_pushing = FALSE;
+    if (player->MovPos == 0)   /* last pushing move finished */
+      player->is_pushing = FALSE;
 
-  if (mode == DF_NO_PUSH)      /* player just stopped pushing */
-  {
-    player->is_switching = FALSE;
-    player->push_delay = 0;
+    if (mode == DF_NO_PUSH)    /* player just stopped pushing */
+    {
+      player->is_switching = FALSE;
+      player->push_delay = -1;
 
-    return MF_NO_ACTION;
+      return MF_NO_ACTION;
+    }
   }
 
   if (IS_MOVING(x, y) || IS_PLAYER(x, y))
     return MF_NO_ACTION;
 
-#if 0
+  if (IS_TUBE(Back[jx][jy]) && game.engine_version >= VERSION_IDENT(2,2,0,0))
+    old_element = Back[jx][jy];
 
-#if 0
-  if (IS_TUBE(Feld[jx][jy]) || IS_TUBE(Back[jx][jy]))
-#else
-  if (IS_TUBE(Feld[jx][jy]) ||
-      (IS_TUBE(Back[jx][jy]) && game.engine_version >= VERSION_IDENT(2,2,0,0)))
-#endif
-  {
-    int i = 0;
-    int tube_element = (IS_TUBE(Feld[jx][jy]) ? Feld[jx][jy] : Back[jx][jy]);
-    int tube_leave_directions[][2] =
-    {
-      { EL_TUBE_ANY,                   MV_LEFT | MV_RIGHT | MV_UP | MV_DOWN },
-      { EL_TUBE_VERTICAL,                                   MV_UP | MV_DOWN },
-      { EL_TUBE_HORIZONTAL,            MV_LEFT | MV_RIGHT                   },
-      { EL_TUBE_VERTICAL_LEFT,         MV_LEFT |            MV_UP | MV_DOWN },
-      { EL_TUBE_VERTICAL_RIGHT,                          MV_RIGHT | MV_UP | MV_DOWN },
-      { EL_TUBE_HORIZONTAL_UP,         MV_LEFT | MV_RIGHT | MV_UP           },
-      { EL_TUBE_HORIZONTAL_DOWN,       MV_LEFT | MV_RIGHT |         MV_DOWN },
-      { EL_TUBE_LEFT_UP,               MV_LEFT |            MV_UP           },
-      { EL_TUBE_LEFT_DOWN,             MV_LEFT |                    MV_DOWN },
-      { EL_TUBE_RIGHT_UP,                        MV_RIGHT | MV_UP           },
-      { EL_TUBE_RIGHT_DOWN,                      MV_RIGHT |         MV_DOWN },
-      { -1,                            MV_LEFT | MV_RIGHT | MV_UP | MV_DOWN }
-    };
+  /* in case of element dropped at player position, check background */
+  else if (Back[jx][jy] != EL_EMPTY &&
+          game.engine_version >= VERSION_IDENT(2,2,0,0))
+    old_element = Back[jx][jy];
 
-    while (tube_leave_directions[i][0] != tube_element)
-    {
-      i++;
-      if (tube_leave_directions[i][0] == -1)   /* should not happen */
-       break;
-    }
+  if (IS_WALKABLE(old_element) && !ACCESS_FROM(old_element, move_direction))
+    return MF_NO_ACTION;       /* field has no opening in this direction */
 
-    if (!(tube_leave_directions[i][1] & move_direction))
-      return MF_NO_ACTION;     /* tube has no opening in this direction */
-  }
+  if (IS_PASSABLE(old_element) && !ACCESS_FROM(old_element,opposite_direction))
+    return MF_NO_ACTION;       /* field has no opening in this direction */
 
+  element = Feld[x][y];
+#if USE_NEW_COLLECT_COUNT
+  collect_count = Count[x][y];
 #else
-
-  if (IS_TUBE(Back[jx][jy]) && game.engine_version >= VERSION_IDENT(2,2,0,0))
-    old_element = Back[jx][jy];
-
+  collect_count = element_info[element].collect_count_initial;
 #endif
 
-  if (IS_WALKABLE(old_element) &&
-      !(element_info[old_element].access_direction & move_direction))
-    return MF_NO_ACTION;       /* field has no opening in this direction */
+#if 0
+  if (element != EL_BLOCKED &&
+      Count[x][y] != element_info[element].collect_count_initial)
+    printf("::: %d: %d != %d\n",
+          element,
+          Count[x][y],
+          element_info[element].collect_count_initial);
+#endif
 
-  element = Feld[x][y];
+  if (!is_player && !IS_COLLECTIBLE(element))  /* penguin cannot collect it */
+    return MF_NO_ACTION;
 
   if (mode == DF_SNAP && !IS_SNAPPABLE(element) &&
       game.engine_version >= VERSION_IDENT(2,2,0,0))
     return MF_NO_ACTION;
 
-  switch (element)
+  if (game.gravity && is_player && !player->is_auto_moving &&
+      canFallDown(player) && move_direction != MV_DOWN &&
+      !canMoveToValidFieldWithGravity(jx, jy, move_direction))
+    return MF_NO_ACTION;       /* player cannot walk here due to gravity */
+
+  if (IS_WALKABLE(element) && ACCESS_FROM(element, opposite_direction))
   {
-    case EL_SP_PORT_LEFT:
-    case EL_SP_PORT_RIGHT:
-    case EL_SP_PORT_UP:
-    case EL_SP_PORT_DOWN:
-    case EL_SP_PORT_HORIZONTAL:
-    case EL_SP_PORT_VERTICAL:
-    case EL_SP_PORT_ANY:
-    case EL_SP_GRAVITY_PORT_LEFT:
-    case EL_SP_GRAVITY_PORT_RIGHT:
-    case EL_SP_GRAVITY_PORT_UP:
-    case EL_SP_GRAVITY_PORT_DOWN:
-#if 1
-      if (!canEnterSupaplexPort(x, y, dx, dy))
+    int sound_element = SND_ELEMENT(element);
+    int sound_action = ACTION_WALKING;
+
+    if (IS_RND_GATE(element))
+    {
+      if (!player->key[RND_GATE_NR(element)])
        return MF_NO_ACTION;
-#else
-      if ((dx == -1 &&
-          element != EL_SP_PORT_LEFT &&
-          element != EL_SP_GRAVITY_PORT_LEFT &&
-          element != EL_SP_PORT_HORIZONTAL &&
-          element != EL_SP_PORT_ANY) ||
-         (dx == +1 &&
-          element != EL_SP_PORT_RIGHT &&
-          element != EL_SP_GRAVITY_PORT_RIGHT &&
-          element != EL_SP_PORT_HORIZONTAL &&
-          element != EL_SP_PORT_ANY) ||
-         (dy == -1 &&
-          element != EL_SP_PORT_UP &&
-          element != EL_SP_GRAVITY_PORT_UP &&
-          element != EL_SP_PORT_VERTICAL &&
-          element != EL_SP_PORT_ANY) ||
-         (dy == +1 &&
-          element != EL_SP_PORT_DOWN &&
-          element != EL_SP_GRAVITY_PORT_DOWN &&
-          element != EL_SP_PORT_VERTICAL &&
-          element != EL_SP_PORT_ANY) ||
-         !IN_LEV_FIELD(nextx, nexty) ||
-         !IS_FREE(nextx, nexty))
+    }
+    else if (IS_RND_GATE_GRAY(element))
+    {
+      if (!player->key[RND_GATE_GRAY_NR(element)])
        return MF_NO_ACTION;
-#endif
+    }
+    else if (element == EL_EXIT_OPEN ||
+            element == EL_SP_EXIT_OPEN ||
+            element == EL_SP_EXIT_OPENING)
+    {
+      sound_action = ACTION_PASSING;   /* player is passing exit */
+    }
+    else if (element == EL_EMPTY)
+    {
+      sound_action = ACTION_MOVING;            /* nothing to walk on */
+    }
+
+    /* play sound from background or player, whatever is available */
+    if (element_info[sound_element].sound[sound_action] != SND_UNDEFINED)
+      PlayLevelSoundElementAction(x, y, sound_element, sound_action);
+    else
+      PlayLevelSoundElementAction(x, y, player->element_nr, sound_action);
+  }
+  else if (IS_PASSABLE(element) && canPassField(x, y, move_direction))
+  {
+    if (!ACCESS_FROM(element, opposite_direction))
+      return MF_NO_ACTION;     /* field not accessible from this direction */
+
+    if (CAN_MOVE(element))     /* only fixed elements can be passed! */
+      return MF_NO_ACTION;
 
+    if (IS_EM_GATE(element))
+    {
+      if (!player->key[EM_GATE_NR(element)])
+       return MF_NO_ACTION;
+    }
+    else if (IS_EM_GATE_GRAY(element))
+    {
+      if (!player->key[EM_GATE_GRAY_NR(element)])
+       return MF_NO_ACTION;
+    }
+    else if (IS_SP_PORT(element))
+    {
       if (element == EL_SP_GRAVITY_PORT_LEFT ||
          element == EL_SP_GRAVITY_PORT_RIGHT ||
          element == EL_SP_GRAVITY_PORT_UP ||
          element == EL_SP_GRAVITY_PORT_DOWN)
        game.gravity = !game.gravity;
+      else if (element == EL_SP_GRAVITY_ON_PORT_LEFT ||
+              element == EL_SP_GRAVITY_ON_PORT_RIGHT ||
+              element == EL_SP_GRAVITY_ON_PORT_UP ||
+              element == EL_SP_GRAVITY_ON_PORT_DOWN)
+       game.gravity = TRUE;
+      else if (element == EL_SP_GRAVITY_OFF_PORT_LEFT ||
+              element == EL_SP_GRAVITY_OFF_PORT_RIGHT ||
+              element == EL_SP_GRAVITY_OFF_PORT_UP ||
+              element == EL_SP_GRAVITY_OFF_PORT_DOWN)
+       game.gravity = FALSE;
+    }
 
-      /* automatically move to the next field with double speed */
-      player->programmed_action = move_direction;
-#if 1
-      if (player->move_delay_reset_counter == 0)
-      {
-       player->move_delay_reset_counter = 2;   /* two double speed steps */
+    /* automatically move to the next field with double speed */
+    player->programmed_action = move_direction;
 
-       DOUBLE_PLAYER_SPEED(player);
-      }
-#else
-      player->move_delay_reset_counter = 2;
+    if (player->move_delay_reset_counter == 0)
+    {
+      player->move_delay_reset_counter = 2;    /* two double speed steps */
 
       DOUBLE_PLAYER_SPEED(player);
-#endif
-
-#if 0
-      printf("::: passing port %d,%d [%d]\n", x, y, FrameCounter);
-#endif
-
-      PlayLevelSound(x, y, SND_CLASS_SP_PORT_PASSING);
-      break;
-
-#if 0
-    case EL_TUBE_ANY:
-    case EL_TUBE_VERTICAL:
-    case EL_TUBE_HORIZONTAL:
-    case EL_TUBE_VERTICAL_LEFT:
-    case EL_TUBE_VERTICAL_RIGHT:
-    case EL_TUBE_HORIZONTAL_UP:
-    case EL_TUBE_HORIZONTAL_DOWN:
-    case EL_TUBE_LEFT_UP:
-    case EL_TUBE_LEFT_DOWN:
-    case EL_TUBE_RIGHT_UP:
-    case EL_TUBE_RIGHT_DOWN:
-      {
-       int i = 0;
-       int tube_enter_directions[][2] =
-       {
-         { EL_TUBE_ANY,                MV_LEFT | MV_RIGHT | MV_UP | MV_DOWN },
-         { EL_TUBE_VERTICAL,                                MV_UP | MV_DOWN },
-         { EL_TUBE_HORIZONTAL,         MV_LEFT | MV_RIGHT                   },
-         { EL_TUBE_VERTICAL_LEFT,                MV_RIGHT | MV_UP | MV_DOWN },
-         { EL_TUBE_VERTICAL_RIGHT,     MV_LEFT            | MV_UP | MV_DOWN },
-         { EL_TUBE_HORIZONTAL_UP,      MV_LEFT | MV_RIGHT |         MV_DOWN },
-         { EL_TUBE_HORIZONTAL_DOWN,    MV_LEFT | MV_RIGHT | MV_UP           },
-         { EL_TUBE_LEFT_UP,                      MV_RIGHT |         MV_DOWN },
-         { EL_TUBE_LEFT_DOWN,                    MV_RIGHT | MV_UP           },
-         { EL_TUBE_RIGHT_UP,           MV_LEFT |                    MV_DOWN },
-         { EL_TUBE_RIGHT_DOWN,         MV_LEFT |            MV_UP           },
-         { -1,                         MV_NO_MOVING                         }
-       };
-
-       while (tube_enter_directions[i][0] != element)
-       {
-         i++;
-         if (tube_enter_directions[i][0] == -1)        /* should not happen */
-           break;
-       }
-
-       if (!(tube_enter_directions[i][1] & move_direction))
-         return MF_NO_ACTION;  /* tube has no opening in this direction */
-
-       PlayLevelSound(x, y, SND_CLASS_TUBE_WALKING);
-      }
-      break;
-#endif
-
-    default:
-
-      if (IS_WALKABLE(element))
-      {
-       int sound_action = ACTION_WALKING;
-
-       if (!(element_info[element].access_direction & opposite_direction))
-         return MF_NO_ACTION;  /* field not accessible from this direction */
-
-       if (element >= EL_GATE_1 && element <= EL_GATE_4)
-       {
-         if (!player->key[element - EL_GATE_1])
-           return MF_NO_ACTION;
-       }
-       else if (element >= EL_GATE_1_GRAY && element <= EL_GATE_4_GRAY)
-       {
-         if (!player->key[element - EL_GATE_1_GRAY])
-           return MF_NO_ACTION;
-       }
-       else if (element == EL_EXIT_OPEN ||
-                element == EL_SP_EXIT_OPEN ||
-                element == EL_SP_EXIT_OPENING)
-       {
-         sound_action = ACTION_PASSING;        /* player is passing exit */
-       }
-       else if (element == EL_EMPTY)
-       {
-         sound_action = ACTION_MOVING;         /* nothing to walk on */
-       }
-
-       /* play sound from background or player, whatever is available */
-       if (element_info[element].sound[sound_action] != SND_UNDEFINED)
-         PlayLevelSoundElementAction(x, y, element, sound_action);
-       else
-         PlayLevelSoundElementAction(x, y, player->element_nr, sound_action);
-
-       break;
-      }
-      else if (IS_PASSABLE(element))
-      {
-       if (!IN_LEV_FIELD(nextx, nexty) || !IS_FREE(nextx, nexty))
-         return MF_NO_ACTION;
-
-       if (IS_CUSTOM_ELEMENT(element) &&
-           !(element_info[element].access_direction & opposite_direction))
-         return MF_NO_ACTION;  /* field not accessible from this direction */
-
-#if 1
-       if (CAN_MOVE(element))  /* only fixed elements can be passed! */
-         return MF_NO_ACTION;
-#endif
-
-       if (element >= EL_EM_GATE_1 && element <= EL_EM_GATE_4)
-       {
-         if (!player->key[element - EL_EM_GATE_1])
-           return MF_NO_ACTION;
-       }
-       else if (element >= EL_EM_GATE_1_GRAY && element <= EL_EM_GATE_4_GRAY)
-       {
-         if (!player->key[element - EL_EM_GATE_1_GRAY])
-           return MF_NO_ACTION;
-       }
-
-       /* automatically move to the next field with double speed */
-       player->programmed_action = move_direction;
-#if 1
-       if (player->move_delay_reset_counter == 0)
-       {
-         player->move_delay_reset_counter = 2; /* two double speed steps */
+    }
 
-         DOUBLE_PLAYER_SPEED(player);
-       }
-#else
-       player->move_delay_reset_counter = 2;
+    PlayLevelSoundAction(x, y, ACTION_PASSING);
+  }
+  else if (IS_DIGGABLE(element))
+  {
+    RemoveField(x, y);
 
-       DOUBLE_PLAYER_SPEED(player);
-#endif
+    if (mode != DF_SNAP)
+    {
+      GfxElement[x][y] = GFX_ELEMENT(element);
+      player->is_digging = TRUE;
+    }
 
-       PlayLevelSoundAction(x, y, ACTION_PASSING);
+    PlayLevelSoundElementAction(x, y, element, ACTION_DIGGING);
 
-       break;
-      }
-      else if (IS_DIGGABLE(element))
-      {
-       RemoveField(x, y);
+    CheckTriggeredElementChangeByPlayer(element, CE_PLAYER_DIGS_X,
+                                       player->index_bit, dig_side);
 
-       if (mode != DF_SNAP)
-       {
-#if 1
-         GfxElement[x][y] = GFX_ELEMENT(element);
-#else
-         GfxElement[x][y] =
-           (GFX_CRUMBLED(element) ? EL_SAND : GFX_ELEMENT(element));
-#endif
-         player->is_digging = TRUE;
-       }
+    if (mode == DF_SNAP)
+      TestIfElementTouchesCustomElement(x, y); /* for empty space */
+  }
+  else if (IS_COLLECTIBLE(element))
+  {
+    RemoveField(x, y);
 
-       PlayLevelSoundElementAction(x, y, element, ACTION_DIGGING);
+    if (is_player && mode != DF_SNAP)
+    {
+      GfxElement[x][y] = element;
+      player->is_collecting = TRUE;
+    }
 
-       CheckTriggeredElementChangePlayer(x, y, element, CE_OTHER_GETS_DIGGED,
-                                         player->index_bit, dig_side);
+    if (element == EL_SPEED_PILL)
+    {
+      player->move_delay_value = MOVE_DELAY_HIGH_SPEED;
+    }
+    else if (element == EL_EXTRA_TIME && level.time > 0)
+    {
+      TimeLeft += 10;
+      DrawGameValue_Time(TimeLeft);
+    }
+    else if (element == EL_SHIELD_NORMAL || element == EL_SHIELD_DEADLY)
+    {
+      player->shield_normal_time_left += 10;
+      if (element == EL_SHIELD_DEADLY)
+       player->shield_deadly_time_left += 10;
+    }
+    else if (element == EL_DYNAMITE || element == EL_SP_DISK_RED)
+    {
+      if (player->inventory_size < MAX_INVENTORY_SIZE)
+       player->inventory_element[player->inventory_size++] = element;
 
-#if 1
-       if (mode == DF_SNAP)
-         TestIfElementTouchesCustomElement(x, y);      /* for empty space */
-#endif
+      DrawGameValue_Dynamite(local_player->inventory_size);
+    }
+    else if (element == EL_DYNABOMB_INCREASE_NUMBER)
+    {
+      player->dynabomb_count++;
+      player->dynabombs_left++;
+    }
+    else if (element == EL_DYNABOMB_INCREASE_SIZE)
+    {
+      player->dynabomb_size++;
+    }
+    else if (element == EL_DYNABOMB_INCREASE_POWER)
+    {
+      player->dynabomb_xl = TRUE;
+    }
+    else if (IS_KEY(element))
+    {
+      player->key[KEY_NR(element)] = TRUE;
 
-       break;
-      }
-      else if (IS_COLLECTIBLE(element))
-      {
-       RemoveField(x, y);
+      DrawGameValue_Keys(player->key);
 
-       if (mode != DF_SNAP)
-       {
-         GfxElement[x][y] = element;
-         player->is_collecting = TRUE;
-       }
+      redraw_mask |= REDRAW_DOOR_1;
+    }
+    else if (IS_ENVELOPE(element))
+    {
+      player->show_envelope = element;
+    }
+    else if (IS_DROPPABLE(element) ||
+            IS_THROWABLE(element))     /* can be collected and dropped */
+    {
+      int i;
 
-       if (element == EL_SPEED_PILL)
-         player->move_delay_value = MOVE_DELAY_HIGH_SPEED;
-       else if (element == EL_EXTRA_TIME && level.time > 0)
-       {
-         TimeLeft += 10;
-         DrawGameValue_Time(TimeLeft);
-       }
-       else if (element == EL_SHIELD_NORMAL || element == EL_SHIELD_DEADLY)
-       {
-         player->shield_normal_time_left += 10;
-         if (element == EL_SHIELD_DEADLY)
-           player->shield_deadly_time_left += 10;
-       }
-       else if (element == EL_DYNAMITE || element == EL_SP_DISK_RED)
-       {
+      if (collect_count == 0)
+       player->inventory_infinite_element = element;
+      else
+       for (i = 0; i < collect_count; i++)
          if (player->inventory_size < MAX_INVENTORY_SIZE)
            player->inventory_element[player->inventory_size++] = element;
 
-         DrawGameValue_Dynamite(local_player->inventory_size);
-       }
-       else if (element == EL_DYNABOMB_INCREASE_NUMBER)
-       {
-         player->dynabomb_count++;
-         player->dynabombs_left++;
-       }
-       else if (element == EL_DYNABOMB_INCREASE_SIZE)
-       {
-         player->dynabomb_size++;
-       }
-       else if (element == EL_DYNABOMB_INCREASE_POWER)
-       {
-         player->dynabomb_xl = TRUE;
-       }
-       else if ((element >= EL_KEY_1 && element <= EL_KEY_4) ||
-                (element >= EL_EM_KEY_1 && element <= EL_EM_KEY_4))
-       {
-         int key_nr = (element >= EL_KEY_1 && element <= EL_KEY_4 ?
-                       element - EL_KEY_1 : element - EL_EM_KEY_1);
-
-         player->key[key_nr] = TRUE;
-
-         DrawGameValue_Keys(player);
-
-         redraw_mask |= REDRAW_DOOR_1;
-       }
-       else if (IS_ENVELOPE(element))
-       {
-#if 1
-         player->show_envelope = element;
-#else
-         ShowEnvelope(element - EL_ENVELOPE_1);
-#endif
-       }
-       else if (IS_DROPPABLE(element)) /* can be collected and dropped */
-       {
-         int i;
-
-         if (element_info[element].collect_count == 0)
-           player->inventory_infinite_element = element;
-         else
-           for (i = 0; i < element_info[element].collect_count; i++)
-             if (player->inventory_size < MAX_INVENTORY_SIZE)
-               player->inventory_element[player->inventory_size++] = element;
-
-         DrawGameValue_Dynamite(local_player->inventory_size);
-       }
-       else if (element_info[element].collect_count > 0)
-       {
-         local_player->gems_still_needed -=
-           element_info[element].collect_count;
-         if (local_player->gems_still_needed < 0)
-           local_player->gems_still_needed = 0;
+      DrawGameValue_Dynamite(local_player->inventory_size);
+    }
+    else if (collect_count > 0)
+    {
+      local_player->gems_still_needed -= collect_count;
+      if (local_player->gems_still_needed < 0)
+       local_player->gems_still_needed = 0;
 
-         DrawGameValue_Emeralds(local_player->gems_still_needed);
-       }
+      DrawGameValue_Emeralds(local_player->gems_still_needed);
+    }
 
-       RaiseScoreElement(element);
-       PlayLevelSoundElementAction(x, y, element, ACTION_COLLECTING);
+    RaiseScoreElement(element);
+    PlayLevelSoundElementAction(x, y, element, ACTION_COLLECTING);
 
-       CheckTriggeredElementChangePlayer(x, y, element,
-                                         CE_OTHER_GETS_COLLECTED,
+    if (is_player)
+      CheckTriggeredElementChangeByPlayer(element, CE_PLAYER_COLLECTS_X,
                                          player->index_bit, dig_side);
 
-#if 1
-       if (mode == DF_SNAP)
-         TestIfElementTouchesCustomElement(x, y);      /* for empty space */
-#endif
-
-       break;
-      }
-      else if (IS_PUSHABLE(element))
-      {
-       if (mode == DF_SNAP && element != EL_BD_ROCK)
-         return MF_NO_ACTION;
-
-       if (CAN_FALL(element) && dy)
-         return MF_NO_ACTION;
-
-       if (CAN_FALL(element) && IN_LEV_FIELD(x, y + 1) && IS_FREE(x, y + 1) &&
-           !(element == EL_SPRING && level.use_spring_bug))
-         return MF_NO_ACTION;
-
-#if 1
-       if (CAN_MOVE(element) && GET_MAX_MOVE_DELAY(element) == 0 &&
-           ((move_direction & MV_VERTICAL &&
-             ((element_info[element].move_pattern & MV_LEFT &&
-               IN_LEV_FIELD(x - 1, y) && IS_FREE(x - 1, y)) ||
-              (element_info[element].move_pattern & MV_RIGHT &&
-               IN_LEV_FIELD(x + 1, y) && IS_FREE(x + 1, y)))) ||
-            (move_direction & MV_HORIZONTAL &&
-             ((element_info[element].move_pattern & MV_UP &&
-               IN_LEV_FIELD(x, y - 1) && IS_FREE(x, y - 1)) ||
-              (element_info[element].move_pattern & MV_DOWN &&
-               IN_LEV_FIELD(x, y + 1) && IS_FREE(x, y + 1))))))
-         return MF_NO_ACTION;
-#endif
+    if (mode == DF_SNAP)
+      TestIfElementTouchesCustomElement(x, y); /* for empty space */
+  }
+  else if (IS_PUSHABLE(element))
+  {
+    if (mode == DF_SNAP && element != EL_BD_ROCK)
+      return MF_NO_ACTION;
 
-#if 1
-       /* do not push elements already moving away faster than player */
-       if (CAN_MOVE(element) && MovDir[x][y] == move_direction &&
-           ABS(getElementMoveStepsize(x, y)) > MOVE_STEPSIZE_NORMAL)
-         return MF_NO_ACTION;
-#else
-       if (element == EL_SPRING && MovDir[x][y] != MV_NO_MOVING)
-         return MF_NO_ACTION;
-#endif
+    if (CAN_FALL(element) && dy)
+      return MF_NO_ACTION;
 
-#if 1
-       if (game.engine_version >= VERSION_IDENT(3,0,7,1))
-       {
-         if (player->push_delay_value == -1)
-           player->push_delay_value = GET_NEW_PUSH_DELAY(element);
-       }
-       else if (game.engine_version >= VERSION_IDENT(2,2,0,7))
-       {
-         if (!player->is_pushing)
-           player->push_delay_value = GET_NEW_PUSH_DELAY(element);
-       }
+    if (CAN_FALL(element) && IN_LEV_FIELD(x, y + 1) && IS_FREE(x, y + 1) &&
+       !(element == EL_SPRING && level.use_spring_bug))
+      return MF_NO_ACTION;
 
-       /*
-       if (game.engine_version >= VERSION_IDENT(2,2,0,7) &&
-           (game.engine_version < VERSION_IDENT(3,0,7,1) ||
-            !player_is_pushing))
-         player->push_delay_value = GET_NEW_PUSH_DELAY(element);
-       */
-#else
-       if (!player->is_pushing &&
-           game.engine_version >= VERSION_IDENT(2,2,0,7))
-         player->push_delay_value = GET_NEW_PUSH_DELAY(element);
-#endif
+    if (CAN_MOVE(element) && GET_MAX_MOVE_DELAY(element) == 0 &&
+       ((move_direction & MV_VERTICAL &&
+         ((element_info[element].move_pattern & MV_LEFT &&
+           IN_LEV_FIELD(x - 1, y) && IS_FREE(x - 1, y)) ||
+          (element_info[element].move_pattern & MV_RIGHT &&
+           IN_LEV_FIELD(x + 1, y) && IS_FREE(x + 1, y)))) ||
+        (move_direction & MV_HORIZONTAL &&
+         ((element_info[element].move_pattern & MV_UP &&
+           IN_LEV_FIELD(x, y - 1) && IS_FREE(x, y - 1)) ||
+          (element_info[element].move_pattern & MV_DOWN &&
+           IN_LEV_FIELD(x, y + 1) && IS_FREE(x, y + 1))))))
+      return MF_NO_ACTION;
 
-#if 0
-       printf("::: push delay: %ld [%d, %d] [%d]\n",
-              player->push_delay_value, FrameCounter, game.engine_version,
-              player->is_pushing);
-#endif
+    /* do not push elements already moving away faster than player */
+    if (CAN_MOVE(element) && MovDir[x][y] == move_direction &&
+       ABS(getElementMoveStepsize(x, y)) > MOVE_STEPSIZE_NORMAL)
+      return MF_NO_ACTION;
 
-       player->is_pushing = TRUE;
+    if (game.engine_version >= VERSION_IDENT(3,1,0,0))
+    {
+      if (player->push_delay_value == -1 || !player_was_pushing)
+       player->push_delay_value = GET_NEW_PUSH_DELAY(element);
+    }
+    else if (game.engine_version >= VERSION_IDENT(3,0,7,1))
+    {
+      if (player->push_delay_value == -1)
+       player->push_delay_value = GET_NEW_PUSH_DELAY(element);
+    }
+    else if (game.engine_version >= VERSION_IDENT(2,2,0,7))
+    {
+      if (!player->is_pushing)
+       player->push_delay_value = GET_NEW_PUSH_DELAY(element);
+    }
 
-       if (!(IN_LEV_FIELD(nextx, nexty) &&
-             (IS_FREE(nextx, nexty) ||
-              (Feld[nextx][nexty] == EL_SOKOBAN_FIELD_EMPTY &&
-               IS_SB_ELEMENT(element)))))
-         return MF_NO_ACTION;
+    player->is_pushing = TRUE;
 
-       if (!checkDiagonalPushing(player, x, y, real_dx, real_dy))
-         return MF_NO_ACTION;
+    if (!(IN_LEV_FIELD(nextx, nexty) &&
+         (IS_FREE(nextx, nexty) ||
+          (Feld[nextx][nexty] == EL_SOKOBAN_FIELD_EMPTY &&
+           IS_SB_ELEMENT(element)))))
+      return MF_NO_ACTION;
 
-       if (player->push_delay == 0)    /* new pushing; restart delay */
-         player->push_delay = FrameCounter;
+    if (!checkDiagonalPushing(player, x, y, real_dx, real_dy))
+      return MF_NO_ACTION;
 
-       if (!FrameReached(&player->push_delay, player->push_delay_value) &&
-           !(tape.playing && tape.file_version < FILE_VERSION_2_0) &&
-           element != EL_SPRING && element != EL_BALLOON)
-       {
-         /* make sure that there is no move delay before next try to push */
-         if (game.engine_version >= VERSION_IDENT(3,0,7,1))
-           player->move_delay = INITIAL_MOVE_DELAY_OFF;
+    if (player->push_delay == -1)      /* new pushing; restart delay */
+      player->push_delay = 0;
 
-         return MF_NO_ACTION;
-       }
+    if (player->push_delay < player->push_delay_value &&
+       !(tape.playing && tape.file_version < FILE_VERSION_2_0) &&
+       element != EL_SPRING && element != EL_BALLOON)
+    {
+      /* make sure that there is no move delay before next try to push */
+      if (game.engine_version >= VERSION_IDENT(3,0,7,1))
+       player->move_delay = 0;
 
-#if 0
-       printf("::: NOW PUSHING... [%d]\n", FrameCounter);
-#endif
+      return MF_NO_ACTION;
+    }
 
-       if (IS_SB_ELEMENT(element))
-       {
-         if (element == EL_SOKOBAN_FIELD_FULL)
-         {
-           Back[x][y] = EL_SOKOBAN_FIELD_EMPTY;
-           local_player->sokobanfields_still_needed++;
-         }
+    if (IS_SB_ELEMENT(element))
+    {
+      if (element == EL_SOKOBAN_FIELD_FULL)
+      {
+       Back[x][y] = EL_SOKOBAN_FIELD_EMPTY;
+       local_player->sokobanfields_still_needed++;
+      }
 
-         if (Feld[nextx][nexty] == EL_SOKOBAN_FIELD_EMPTY)
-         {
-           Back[nextx][nexty] = EL_SOKOBAN_FIELD_EMPTY;
-           local_player->sokobanfields_still_needed--;
-         }
+      if (Feld[nextx][nexty] == EL_SOKOBAN_FIELD_EMPTY)
+      {
+       Back[nextx][nexty] = EL_SOKOBAN_FIELD_EMPTY;
+       local_player->sokobanfields_still_needed--;
+      }
 
-         Feld[x][y] = EL_SOKOBAN_OBJECT;
+      Feld[x][y] = EL_SOKOBAN_OBJECT;
 
-         if (Back[x][y] == Back[nextx][nexty])
-           PlayLevelSoundAction(x, y, ACTION_PUSHING);
-         else if (Back[x][y] != 0)
-           PlayLevelSoundElementAction(x, y, EL_SOKOBAN_FIELD_FULL,
-                                       ACTION_EMPTYING);
-         else
-           PlayLevelSoundElementAction(nextx, nexty, EL_SOKOBAN_FIELD_EMPTY,
-                                       ACTION_FILLING);
+      if (Back[x][y] == Back[nextx][nexty])
+       PlayLevelSoundAction(x, y, ACTION_PUSHING);
+      else if (Back[x][y] != 0)
+       PlayLevelSoundElementAction(x, y, EL_SOKOBAN_FIELD_FULL,
+                                   ACTION_EMPTYING);
+      else
+       PlayLevelSoundElementAction(nextx, nexty, EL_SOKOBAN_FIELD_EMPTY,
+                                   ACTION_FILLING);
 
-         if (local_player->sokobanfields_still_needed == 0 &&
-             game.emulation == EMU_SOKOBAN)
-         {
-           player->LevelSolved = player->GameOver = TRUE;
-           PlayLevelSound(x, y, SND_GAME_SOKOBAN_SOLVING);
-         }
-       }
-       else
-         PlayLevelSoundElementAction(x, y, element, ACTION_PUSHING);
+      if (local_player->sokobanfields_still_needed == 0 &&
+         game.emulation == EMU_SOKOBAN)
+      {
+       player->LevelSolved = player->GameOver = TRUE;
+       PlayLevelSound(x, y, SND_GAME_SOKOBAN_SOLVING);
+      }
+    }
+    else
+      PlayLevelSoundElementAction(x, y, element, ACTION_PUSHING);
 
-       InitMovingField(x, y, move_direction);
-       GfxAction[x][y] = ACTION_PUSHING;
+    InitMovingField(x, y, move_direction);
+    GfxAction[x][y] = ACTION_PUSHING;
 
-       if (mode == DF_SNAP)
-         ContinueMoving(x, y);
-       else
-         MovPos[x][y] = (dx != 0 ? dx : dy);
+    if (mode == DF_SNAP)
+      ContinueMoving(x, y);
+    else
+      MovPos[x][y] = (dx != 0 ? dx : dy);
 
-       Pushed[x][y] = TRUE;
-       Pushed[nextx][nexty] = TRUE;
+    Pushed[x][y] = TRUE;
+    Pushed[nextx][nexty] = TRUE;
 
-       if (game.engine_version < VERSION_IDENT(2,2,0,7))
-         player->push_delay_value = GET_NEW_PUSH_DELAY(element);
-       else
-         player->push_delay_value = -1;        /* get new value later */
+    if (game.engine_version < VERSION_IDENT(2,2,0,7))
+      player->push_delay_value = GET_NEW_PUSH_DELAY(element);
+    else
+      player->push_delay_value = -1;   /* get new value later */
 
-       CheckTriggeredElementChangePlayer(x, y, element, CE_OTHER_GETS_PUSHED,
-                                         player->index_bit, dig_side);
-       CheckElementChangePlayer(x, y, element, CE_PUSHED_BY_PLAYER,
+    /* check for element change _after_ element has been pushed */
+    if (game.use_change_when_pushing_bug)
+    {
+      CheckElementChangeByPlayer(x, y, element, CE_PUSHED_BY_PLAYER,
                                 player->index_bit, dig_side);
+      CheckTriggeredElementChangeByPlayer(element, CE_PLAYER_PUSHES_X,
+                                         player->index_bit, dig_side);
+    }
+  }
+  else if (IS_SWITCHABLE(element))
+  {
+    if (PLAYER_SWITCHING(player, x, y))
+    {
+      CheckTriggeredElementChangeByPlayer(element, CE_PLAYER_PRESSES_X,
+                                         player->index_bit, dig_side);
 
-       break;
-      }
-      else if (IS_SWITCHABLE(element))
-      {
-       if (PLAYER_SWITCHING(player, x, y))
-         return MF_ACTION;
+      return MF_ACTION;
+    }
 
-       player->is_switching = TRUE;
-       player->switch_x = x;
-       player->switch_y = y;
+    player->is_switching = TRUE;
+    player->switch_x = x;
+    player->switch_y = y;
 
-       PlayLevelSoundElementAction(x, y, element, ACTION_ACTIVATING);
+    PlayLevelSoundElementAction(x, y, element, ACTION_ACTIVATING);
 
-       if (element == EL_ROBOT_WHEEL)
-       {
-         Feld[x][y] = EL_ROBOT_WHEEL_ACTIVE;
-         ZX = x;
-         ZY = y;
+    if (element == EL_ROBOT_WHEEL)
+    {
+      Feld[x][y] = EL_ROBOT_WHEEL_ACTIVE;
+      ZX = x;
+      ZY = y;
 
-         DrawLevelField(x, y);
-       }
-       else if (element == EL_SP_TERMINAL)
-       {
-         int xx, yy;
+      DrawLevelField(x, y);
+    }
+    else if (element == EL_SP_TERMINAL)
+    {
+      int xx, yy;
 
-         for (yy = 0; yy < lev_fieldy; yy++) for (xx=0; xx < lev_fieldx; xx++)
-         {
-           if (Feld[xx][yy] == EL_SP_DISK_YELLOW)
-             Bang(xx, yy);
-           else if (Feld[xx][yy] == EL_SP_TERMINAL)
-             Feld[xx][yy] = EL_SP_TERMINAL_ACTIVE;
-         }
-       }
-       else if (IS_BELT_SWITCH(element))
-       {
-         ToggleBeltSwitch(x, y);
-       }
-       else if (element == EL_SWITCHGATE_SWITCH_UP ||
-                element == EL_SWITCHGATE_SWITCH_DOWN)
-       {
-         ToggleSwitchgateSwitch(x, y);
-       }
-       else if (element == EL_LIGHT_SWITCH ||
-                element == EL_LIGHT_SWITCH_ACTIVE)
-       {
-         ToggleLightSwitch(x, y);
+      for (yy = 0; yy < lev_fieldy; yy++) for (xx=0; xx < lev_fieldx; xx++)
+      {
+       if (Feld[xx][yy] == EL_SP_DISK_YELLOW)
+         Bang(xx, yy);
+       else if (Feld[xx][yy] == EL_SP_TERMINAL)
+         Feld[xx][yy] = EL_SP_TERMINAL_ACTIVE;
+      }
+    }
+    else if (IS_BELT_SWITCH(element))
+    {
+      ToggleBeltSwitch(x, y);
+    }
+    else if (element == EL_SWITCHGATE_SWITCH_UP ||
+            element == EL_SWITCHGATE_SWITCH_DOWN)
+    {
+      ToggleSwitchgateSwitch(x, y);
+    }
+    else if (element == EL_LIGHT_SWITCH ||
+            element == EL_LIGHT_SWITCH_ACTIVE)
+    {
+      ToggleLightSwitch(x, y);
+    }
+    else if (element == EL_TIMEGATE_SWITCH)
+    {
+      ActivateTimegateSwitch(x, y);
+    }
+    else if (element == EL_BALLOON_SWITCH_LEFT ||
+            element == EL_BALLOON_SWITCH_RIGHT ||
+            element == EL_BALLOON_SWITCH_UP ||
+            element == EL_BALLOON_SWITCH_DOWN ||
+            element == EL_BALLOON_SWITCH_ANY)
+    {
+      if (element == EL_BALLOON_SWITCH_ANY)
+       game.balloon_dir = move_direction;
+      else
+       game.balloon_dir = (element == EL_BALLOON_SWITCH_LEFT  ? MV_LEFT :
+                           element == EL_BALLOON_SWITCH_RIGHT ? MV_RIGHT :
+                           element == EL_BALLOON_SWITCH_UP    ? MV_UP :
+                           element == EL_BALLOON_SWITCH_DOWN  ? MV_DOWN :
+                           MV_NO_MOVING);
+    }
+    else if (element == EL_LAMP)
+    {
+      Feld[x][y] = EL_LAMP_ACTIVE;
+      local_player->lights_still_needed--;
 
-#if 0
-         PlayLevelSound(x, y, element == EL_LIGHT_SWITCH ?
-                        SND_LIGHT_SWITCH_ACTIVATING :
-                        SND_LIGHT_SWITCH_DEACTIVATING);
-#endif
-       }
-       else if (element == EL_TIMEGATE_SWITCH)
-       {
-         ActivateTimegateSwitch(x, y);
-       }
-       else if (element == EL_BALLOON_SWITCH_LEFT ||
-                element == EL_BALLOON_SWITCH_RIGHT ||
-                element == EL_BALLOON_SWITCH_UP ||
-                element == EL_BALLOON_SWITCH_DOWN ||
-                element == EL_BALLOON_SWITCH_ANY)
-       {
-         if (element == EL_BALLOON_SWITCH_ANY)
-           game.balloon_dir = move_direction;
-         else
-           game.balloon_dir = (element == EL_BALLOON_SWITCH_LEFT  ? MV_LEFT :
-                               element == EL_BALLOON_SWITCH_RIGHT ? MV_RIGHT :
-                               element == EL_BALLOON_SWITCH_UP    ? MV_UP :
-                               element == EL_BALLOON_SWITCH_DOWN  ? MV_DOWN :
-                               MV_NO_MOVING);
-       }
-       else if (element == EL_LAMP)
-       {
-         Feld[x][y] = EL_LAMP_ACTIVE;
-         local_player->lights_still_needed--;
+      ResetGfxAnimation(x, y);
+      DrawLevelField(x, y);
+    }
+    else if (element == EL_TIME_ORB_FULL)
+    {
+      Feld[x][y] = EL_TIME_ORB_EMPTY;
+      TimeLeft += 10;
+      DrawGameValue_Time(TimeLeft);
 
-         DrawLevelField(x, y);
-       }
-       else if (element == EL_TIME_ORB_FULL)
-       {
-         Feld[x][y] = EL_TIME_ORB_EMPTY;
-         TimeLeft += 10;
-         DrawGameValue_Time(TimeLeft);
+      ResetGfxAnimation(x, y);
+      DrawLevelField(x, y);
+    }
 
-         DrawLevelField(x, y);
+    CheckTriggeredElementChangeByPlayer(element, CE_SWITCH_OF_X,
+                                       player->index_bit, dig_side);
 
-#if 0
-         PlaySoundStereo(SND_TIME_ORB_FULL_COLLECTING, SOUND_MIDDLE);
-#endif
-       }
+    CheckTriggeredElementChangeByPlayer(element, CE_PLAYER_PRESSES_X,
+                                       player->index_bit, dig_side);
 
-       return MF_ACTION;
-      }
-      else
-      {
-       if (!PLAYER_SWITCHING(player, x, y))
-       {
-         player->is_switching = TRUE;
-         player->switch_x = x;
-         player->switch_y = y;
-
-         CheckTriggeredElementChangePlayer(x, y, element,
-                                           CE_OTHER_IS_SWITCHING,
-                                           player->index_bit, dig_side);
-         CheckElementChangePlayer(x, y, element, CE_SWITCHED,
-                                  player->index_bit, dig_side);
-       }
+    return MF_ACTION;
+  }
+  else
+  {
+    if (!PLAYER_SWITCHING(player, x, y))
+    {
+      player->is_switching = TRUE;
+      player->switch_x = x;
+      player->switch_y = y;
 
-       CheckTriggeredElementChangePlayer(x, y, element, CE_OTHER_GETS_PRESSED,
-                                         player->index_bit, dig_side);
-       CheckElementChangePlayer(x, y, element, CE_PRESSED_BY_PLAYER,
+      CheckElementChangeByPlayer(x, y, element, CE_SWITCHED,
                                 player->index_bit, dig_side);
-      }
+      CheckTriggeredElementChangeByPlayer(element, CE_SWITCH_OF_X,
+                                         player->index_bit, dig_side);
+    }
 
-      return MF_NO_ACTION;
+    CheckElementChangeByPlayer(x, y, element, CE_PRESSED_BY_PLAYER,
+                              player->index_bit, dig_side);
+    CheckTriggeredElementChangeByPlayer(element, CE_PLAYER_PRESSES_X,
+                                       player->index_bit, dig_side);
+
+    return MF_NO_ACTION;
   }
 
-  player->push_delay = 0;
+  player->push_delay = -1;
 
-  if (Feld[x][y] != element)           /* really digged/collected something */
-    player->is_collecting = !player->is_digging;
+  if (is_player)               /* function can also be called by EL_PENGUIN */
+  {
+    if (Feld[x][y] != element)         /* really digged/collected something */
+      player->is_collecting = !player->is_digging;
+  }
 
   return MF_MOVING;
 }
@@ -10641,13 +9819,8 @@ boolean SnapField(struct PlayerInfo *player, int dx, int dy)
                        dy == -1 ? MV_UP :
                        dy == +1 ? MV_DOWN : MV_NO_MOVING);
 
-#if 0
-  if (player->MovPos)
+  if (player->MovPos != 0 && game.engine_version >= VERSION_IDENT(2,2,0,0))
     return FALSE;
-#else
-  if (player->MovPos && game.engine_version >= VERSION_IDENT(2,2,0,0))
-    return FALSE;
-#endif
 
   if (!player->active || !IN_LEV_FIELD(x, y))
     return FALSE;
@@ -10677,9 +9850,7 @@ boolean SnapField(struct PlayerInfo *player, int dx, int dy)
 
   player->MovDir = snap_direction;
 
-#if 1
   if (player->MovPos == 0)
-#endif
   {
     player->is_moving = FALSE;
     player->is_digging = FALSE;
@@ -10693,77 +9864,75 @@ boolean SnapField(struct PlayerInfo *player, int dx, int dy)
 
   player->is_snapping = TRUE;
 
-#if 1
   if (player->MovPos == 0)
-#endif
   {
     player->is_moving = FALSE;
     player->is_digging = FALSE;
     player->is_collecting = FALSE;
   }
 
+  if (player->MovPos != 0)     /* prevent graphic bugs in versions < 2.2.0 */
+    DrawLevelField(player->last_jx, player->last_jy);
+
   DrawLevelField(x, y);
-  BackToFront();
 
   return TRUE;
 }
 
 boolean DropElement(struct PlayerInfo *player)
 {
-  static int trigger_sides[4] =
-  {
-    CH_SIDE_LEFT,      /* dropping left  */
-    CH_SIDE_RIGHT,     /* dropping right */
-    CH_SIDE_TOP,       /* dropping up    */
-    CH_SIDE_BOTTOM,    /* dropping down  */
-  };
-  int jx = player->jx, jy = player->jy;
+  int old_element, new_element;
+  int dropx = player->jx, dropy = player->jy;
   int drop_direction = player->MovDir;
-  int drop_side = trigger_sides[MV_DIR_BIT(drop_direction)];
-  int old_element = Feld[jx][jy];
-  int new_element = (player->inventory_size > 0 ?
-                    player->inventory_element[player->inventory_size - 1] :
-                    player->inventory_infinite_element != EL_UNDEFINED ?
-                    player->inventory_infinite_element :
-                    player->dynabombs_left > 0 ?
-                    EL_DYNABOMB_PLAYER_1_ACTIVE + player->index_nr :
-                    EL_UNDEFINED);
+  int drop_side = drop_direction;
+  int drop_element = (player->inventory_size > 0 ?
+                     player->inventory_element[player->inventory_size - 1] :
+                     player->inventory_infinite_element != EL_UNDEFINED ?
+                     player->inventory_infinite_element :
+                     player->dynabombs_left > 0 ?
+                     EL_DYNABOMB_PLAYER_1_ACTIVE + player->index_nr :
+                     EL_UNDEFINED);
+
+  /* do not drop an element on top of another element; when holding drop key
+     pressed without moving, dropped element must move away before the next
+     element can be dropped (this is especially important if the next element
+     is dynamite, which can be placed on background for historical reasons) */
+  if (PLAYER_DROPPING(player, dropx, dropy) && Feld[dropx][dropy] != EL_EMPTY)
+    return MF_ACTION;
+
+  if (IS_THROWABLE(drop_element))
+  {
+    dropx += GET_DX_FROM_DIR(drop_direction);
+    dropy += GET_DY_FROM_DIR(drop_direction);
+
+    if (!IN_LEV_FIELD(dropx, dropy))
+      return FALSE;
+  }
+
+  old_element = Feld[dropx][dropy];    /* old element at dropping position */
+  new_element = drop_element;          /* default: no change when dropping */
 
   /* check if player is active, not moving and ready to drop */
   if (!player->active || player->MovPos || player->drop_delay > 0)
     return FALSE;
 
   /* check if player has anything that can be dropped */
-#if 1
   if (new_element == EL_UNDEFINED)
     return FALSE;
-#else
-  if (player->inventory_size == 0 &&
-      player->inventory_infinite_element == EL_UNDEFINED &&
-      player->dynabombs_left == 0)
-    return FALSE;
-#endif
 
   /* check if anything can be dropped at the current position */
   if (IS_ACTIVE_BOMB(old_element) || old_element == EL_EXPLOSION)
     return FALSE;
 
   /* collected custom elements can only be dropped on empty fields */
-#if 1
   if (IS_CUSTOM_ELEMENT(new_element) && old_element != EL_EMPTY)
     return FALSE;
-#else
-  if (player->inventory_size > 0 &&
-      IS_CUSTOM_ELEMENT(player->inventory_element[player->inventory_size - 1])
-      && old_element != EL_EMPTY)
-    return FALSE;
-#endif
 
   if (old_element != EL_EMPTY)
-    Back[jx][jy] = old_element;                /* store old element on this field */
+    Back[dropx][dropy] = old_element;  /* store old element on this field */
 
-  ResetGfxAnimation(jx, jy);
-  ResetRandomAnimationValue(jx, jy);
+  ResetGfxAnimation(dropx, dropy);
+  ResetRandomAnimationValue(dropx, dropy);
 
   if (player->inventory_size > 0 ||
       player->inventory_infinite_element != EL_UNDEFINED)
@@ -10772,10 +9941,6 @@ boolean DropElement(struct PlayerInfo *player)
     {
       player->inventory_size--;
 
-#if 0
-      new_element = player->inventory_element[player->inventory_size];
-#endif
-
       DrawGameValue_Dynamite(local_player->inventory_size);
 
       if (new_element == EL_DYNAMITE)
@@ -10784,106 +9949,63 @@ boolean DropElement(struct PlayerInfo *player)
        new_element = EL_SP_DISK_RED_ACTIVE;
     }
 
-    Feld[jx][jy] = new_element;
+    Feld[dropx][dropy] = new_element;
 
-    if (IN_SCR_FIELD(SCREENX(jx), SCREENY(jy)))
-      DrawGraphicThruMask(SCREENX(jx), SCREENY(jy), el2img(Feld[jx][jy]), 0);
+    if (IN_SCR_FIELD(SCREENX(dropx), SCREENY(dropy)))
+      DrawGraphicThruMask(SCREENX(dropx), SCREENY(dropy),
+                         el2img(Feld[dropx][dropy]), 0);
 
-    PlayLevelSoundAction(jx, jy, ACTION_DROPPING);
+    PlayLevelSoundAction(dropx, dropy, ACTION_DROPPING);
 
-#if 1
     /* needed if previous element just changed to "empty" in the last frame */
-    Changed[jx][jy] = 0;               /* allow another change */
-#endif
+    Changed[dropx][dropy] = FALSE;             /* allow another change */
 
-    CheckTriggeredElementChangePlayer(jx, jy, new_element,
-                                     CE_OTHER_GETS_DROPPED,
-                                     player->index_bit, drop_side);
-    CheckElementChangePlayer(jx, jy, new_element, CE_DROPPED_BY_PLAYER,
-                            player->index_bit, drop_side);
+    CheckElementChangeByPlayer(dropx, dropy, new_element, CE_DROPPED_BY_PLAYER,
+                              player->index_bit, drop_side);
+    CheckTriggeredElementChangeByPlayer(new_element, CE_PLAYER_DROPS_X,
+                                       player->index_bit, drop_side);
 
-    TestIfElementTouchesCustomElement(jx, jy);
+    TestIfElementTouchesCustomElement(dropx, dropy);
   }
   else         /* player is dropping a dyna bomb */
   {
     player->dynabombs_left--;
 
-#if 0
-    new_element = EL_DYNABOMB_PLAYER_1_ACTIVE + player->index_nr;
-#endif
-
-    Feld[jx][jy] = new_element;
+    Feld[dropx][dropy] = new_element;
 
-    if (IN_SCR_FIELD(SCREENX(jx), SCREENY(jy)))
-      DrawGraphicThruMask(SCREENX(jx), SCREENY(jy), el2img(Feld[jx][jy]), 0);
+    if (IN_SCR_FIELD(SCREENX(dropx), SCREENY(dropy)))
+      DrawGraphicThruMask(SCREENX(dropx), SCREENY(dropy),
+                         el2img(Feld[dropx][dropy]), 0);
 
-    PlayLevelSoundAction(jx, jy, ACTION_DROPPING);
+    PlayLevelSoundAction(dropx, dropy, ACTION_DROPPING);
   }
 
+  if (Feld[dropx][dropy] == new_element) /* uninitialized unless CE change */
+    InitField_WithBug1(dropx, dropy, FALSE);
 
-
-#if 1
-
-  if (Feld[jx][jy] == new_element)     /* uninitialized unless CE change */
-  {
-#if 1
-    InitField_WithBug1(jx, jy, FALSE);
-#else
-    InitField(jx, jy, FALSE);
-    if (CAN_MOVE(Feld[jx][jy]))
-      InitMovDir(jx, jy);
-#endif
-  }
-
-  new_element = Feld[jx][jy];
+  new_element = Feld[dropx][dropy];    /* element might have changed */
 
   if (IS_CUSTOM_ELEMENT(new_element) && CAN_MOVE(new_element) &&
       element_info[new_element].move_pattern == MV_WHEN_DROPPED)
   {
-    int move_stepsize = element_info[new_element].move_stepsize;
-    int direction, dx, dy, nextx, nexty;
+    int move_direction, nextx, nexty;
 
     if (element_info[new_element].move_direction_initial == MV_START_AUTOMATIC)
-      MovDir[jx][jy] = player->MovDir;
-
-    direction = MovDir[jx][jy];
-    dx = (direction == MV_LEFT ? -1 : direction == MV_RIGHT ? +1 : 0);
-    dy = (direction == MV_UP   ? -1 : direction == MV_DOWN  ? +1 : 0);
-    nextx = jx + dx;
-    nexty = jy + dy;
-
-    if (IN_LEV_FIELD(nextx, nexty) && IS_FREE(nextx, nexty))
-    {
-#if 0
-      WasJustMoving[jx][jy] = 3;
-#else
-      InitMovingField(jx, jy, direction);
-      ContinueMoving(jx, jy);
-#endif
-    }
-    else
-    {
-      Changed[jx][jy] = 0;             /* allow another change */
+      MovDir[dropx][dropy] = drop_direction;
 
-#if 1
-      TestIfElementHitsCustomElement(jx, jy, direction);
-#else
-      CheckElementChangeSide(jx, jy, new_element, touched_element,
-                            CE_HITTING_SOMETHING, direction);
-#endif
-    }
+    move_direction = MovDir[dropx][dropy];
+    nextx = dropx + GET_DX_FROM_DIR(move_direction);
+    nexty = dropy + GET_DY_FROM_DIR(move_direction);
 
-    player->drop_delay = 2 * TILEX / move_stepsize + 1;
+    Changed[dropx][dropy] = FALSE;             /* allow another change */
+    CheckCollision[dropx][dropy] = 2;
   }
 
-#if 0
-  player->drop_delay = 8 + 8 + 8;
-#endif
-
-#endif
-
+  player->drop_delay = GET_NEW_DROP_DELAY(drop_element);
   player->is_dropping = TRUE;
 
+  player->drop_x = dropx;
+  player->drop_y = dropy;
 
   return TRUE;
 }
@@ -10967,7 +10089,7 @@ static void PlayLevelSoundAction(int x, int y, int action)
 
 static void PlayLevelSoundElementAction(int x, int y, int element, int action)
 {
-  int sound_effect = element_info[element].sound[action];
+  int sound_effect = element_info[SND_ELEMENT(element)].sound[action];
 
   if (sound_effect != SND_UNDEFINED)
     PlayLevelSound(x, y, sound_effect);
@@ -10976,7 +10098,7 @@ static void PlayLevelSoundElementAction(int x, int y, int element, int action)
 static void PlayLevelSoundElementActionIfLoop(int x, int y, int element,
                                              int action)
 {
-  int sound_effect = element_info[element].sound[action];
+  int sound_effect = element_info[SND_ELEMENT(element)].sound[action];
 
   if (sound_effect != SND_UNDEFINED && IS_LOOP_SOUND(sound_effect))
     PlayLevelSound(x, y, sound_effect);
@@ -10984,7 +10106,7 @@ static void PlayLevelSoundElementActionIfLoop(int x, int y, int element,
 
 static void PlayLevelSoundActionIfLoop(int x, int y, int action)
 {
-  int sound_effect = element_info[Feld[x][y]].sound[action];
+  int sound_effect = element_info[SND_ELEMENT(Feld[x][y])].sound[action];
 
   if (sound_effect != SND_UNDEFINED && IS_LOOP_SOUND(sound_effect))
     PlayLevelSound(x, y, sound_effect);
@@ -10992,7 +10114,7 @@ static void PlayLevelSoundActionIfLoop(int x, int y, int action)
 
 static void StopLevelSoundActionIfLoop(int x, int y, int action)
 {
-  int sound_effect = element_info[Feld[x][y]].sound[action];
+  int sound_effect = element_info[SND_ELEMENT(Feld[x][y])].sound[action];
 
   if (sound_effect != SND_UNDEFINED && IS_LOOP_SOUND(sound_effect))
     StopSound(sound_effect);
@@ -11006,6 +10128,163 @@ static void PlayLevelMusic()
     PlayMusic(MAP_NOCONF_MUSIC(level_nr));     /* from music dir */
 }
 
+void PlayLevelSound_EM(int x, int y, int element_em, int sample)
+{
+  int element = (element_em > -1 ? map_element_EM_to_RND(element_em) : 0);
+
+  switch (sample)
+  {
+    case SAMPLE_blank:
+      PlayLevelSoundElementAction(x, y, element, ACTION_WALKING);
+      break;
+
+    case SAMPLE_roll:
+      PlayLevelSoundElementAction(x, y, element, ACTION_PUSHING);
+      break;
+
+    case SAMPLE_stone:
+      PlayLevelSoundElementAction(x, y, element, ACTION_IMPACT);
+      break;
+
+    case SAMPLE_nut:
+      PlayLevelSoundElementAction(x, y, element, ACTION_IMPACT);
+      break;
+
+    case SAMPLE_crack:
+      PlayLevelSoundElementAction(x, y, element, ACTION_BREAKING);
+      break;
+
+    case SAMPLE_bug:
+      PlayLevelSoundElementAction(x, y, element, ACTION_MOVING);
+      break;
+
+    case SAMPLE_tank:
+      PlayLevelSoundElementAction(x, y, element, ACTION_MOVING);
+      break;
+
+    case SAMPLE_android_clone:
+      PlayLevelSoundElementAction(x, y, element, ACTION_DROPPING);
+      break;
+
+    case SAMPLE_android_move:
+      PlayLevelSoundElementAction(x, y, element, ACTION_MOVING);
+      break;
+
+    case SAMPLE_spring:
+      PlayLevelSoundElementAction(x, y, element, ACTION_IMPACT);
+      break;
+
+    case SAMPLE_slurp:
+      PlayLevelSoundElementAction(x, y, element, ACTION_SLURPED_BY_SPRING);
+      break;
+
+    case SAMPLE_eater:
+      PlayLevelSoundElementAction(x, y, element, ACTION_WAITING);
+      break;
+
+    case SAMPLE_eater_eat:
+      PlayLevelSoundElementAction(x, y, element, ACTION_DIGGING);
+      break;
+
+    case SAMPLE_alien:
+      PlayLevelSoundElementAction(x, y, element, ACTION_MOVING);
+      break;
+
+    case SAMPLE_collect:
+      PlayLevelSoundElementAction(x, y, element, ACTION_COLLECTING);
+      break;
+
+    case SAMPLE_diamond:
+      PlayLevelSoundElementAction(x, y, element, ACTION_IMPACT);
+      break;
+
+    case SAMPLE_squash:
+      /* !!! CHECK THIS !!! */
+#if 1
+      PlayLevelSoundElementAction(x, y, element, ACTION_BREAKING);
+#else
+      PlayLevelSoundElementAction(x, y, element, ACTION_SMASHED_BY_ROCK);
+#endif
+      break;
+
+    case SAMPLE_wonderfall:
+      PlayLevelSoundElementAction(x, y, element, ACTION_FILLING);
+      break;
+
+    case SAMPLE_drip:
+      PlayLevelSoundElementAction(x, y, element, ACTION_IMPACT);
+      break;
+
+    case SAMPLE_push:
+      PlayLevelSoundElementAction(x, y, element, ACTION_PUSHING);
+      break;
+
+    case SAMPLE_dirt:
+      PlayLevelSoundElementAction(x, y, element, ACTION_DIGGING);
+      break;
+
+    case SAMPLE_acid:
+      PlayLevelSoundElementAction(x, y, element, ACTION_SPLASHING);
+      break;
+
+    case SAMPLE_ball:
+      PlayLevelSoundElementAction(x, y, element, ACTION_DROPPING);
+      break;
+
+    case SAMPLE_grow:
+      PlayLevelSoundElementAction(x, y, element, ACTION_GROWING);
+      break;
+
+    case SAMPLE_wonder:
+      PlayLevelSoundElementAction(x, y, element, ACTION_ACTIVE);
+      break;
+
+    case SAMPLE_door:
+      PlayLevelSoundElementAction(x, y, element, ACTION_PASSING);
+      break;
+
+    case SAMPLE_exit_open:
+      PlayLevelSoundElementAction(x, y, element, ACTION_OPENING);
+      break;
+
+    case SAMPLE_exit_leave:
+      PlayLevelSoundElementAction(x, y, element, ACTION_PASSING);
+      break;
+
+    case SAMPLE_dynamite:
+      PlayLevelSoundElementAction(x, y, element, ACTION_DROPPING);
+      break;
+
+    case SAMPLE_tick:
+      PlayLevelSoundElementAction(x, y, element, ACTION_ACTIVE);
+      break;
+
+    case SAMPLE_press:
+      PlayLevelSoundElementAction(x, y, element, ACTION_ACTIVATING);
+      break;
+
+    case SAMPLE_wheel:
+      PlayLevelSoundElementAction(x, y, element, ACTION_ACTIVE);
+      break;
+
+    case SAMPLE_boom:
+      PlayLevelSoundElementAction(x, y, element, ACTION_EXPLODING);
+      break;
+
+    case SAMPLE_die:
+      PlayLevelSoundElementAction(x, y, element, ACTION_DYING);
+      break;
+
+    case SAMPLE_time:
+      PlaySoundStereo(SND_GAME_RUNNING_OUT_OF_TIME, SOUND_MIDDLE);
+      break;
+
+    default:
+      PlayLevelSoundElementAction(x, y, element, ACTION_DEFAULT);
+      break;
+  }
+}
+
 void RaiseScore(int value)
 {
   local_player->score += value;
@@ -11075,6 +10354,14 @@ void RaiseScoreElement(int element)
     case EL_KEY_2:
     case EL_KEY_3:
     case EL_KEY_4:
+    case EL_EM_KEY_1:
+    case EL_EM_KEY_2:
+    case EL_EM_KEY_3:
+    case EL_EM_KEY_4:
+    case EL_EMC_KEY_5:
+    case EL_EMC_KEY_6:
+    case EL_EMC_KEY_7:
+    case EL_EMC_KEY_8:
       RaiseScore(level.score[SC_KEY]);
       break;
     default:
@@ -11091,7 +10378,7 @@ void RequestQuitGame(boolean ask_if_really_quit)
       Request("Do you really want to quit the game ?",
              REQ_ASK | REQ_STAY_CLOSED))
   {
-#if defined(PLATFORM_UNIX)
+#if defined(NETWORK_AVALIABLE)
     if (options.network)
       SendToServer_StopPlaying();
     else
@@ -11103,25 +10390,13 @@ void RequestQuitGame(boolean ask_if_really_quit)
   }
   else
   {
-
-#if 1
-    if (tape.playing && tape.index_search)
-    {
-      SetDrawDeactivationMask(REDRAW_NONE);
-      audio.sound_deactivated = FALSE;
-    }
-#endif
+    if (tape.playing && tape.deactivate_display)
+      TapeDeactivateDisplayOff(TRUE);
 
     OpenDoor(DOOR_OPEN_1 | DOOR_COPY_BACK);
 
-#if 1
-    if (tape.playing && tape.index_search)
-    {
-      SetDrawDeactivationMask(REDRAW_FIELD);
-      audio.sound_deactivated = TRUE;
-    }
-#endif
-
+    if (tape.playing && tape.deactivate_display)
+      TapeDeactivateDisplayOn();
   }
 }
 
@@ -11288,7 +10563,7 @@ static void HandleGameButtons(struct GadgetInfo *gi)
     case GAME_CTRL_ID_PAUSE:
       if (options.network)
       {
-#if defined(PLATFORM_UNIX)
+#if defined(NETWORK_AVALIABLE)
        if (tape.pausing)
          SendToServer_ContinuePlaying();
        else
@@ -11302,7 +10577,7 @@ static void HandleGameButtons(struct GadgetInfo *gi)
     case GAME_CTRL_ID_PLAY:
       if (tape.pausing)
       {
-#if defined(PLATFORM_UNIX)
+#if defined(NETWORK_AVALIABLE)
        if (options.network)
          SendToServer_ContinuePlaying();
        else