-#define EP_PLAYER 25
-#define EP_WALKABLE_OVER 26
-#define EP_WALKABLE_THROUGH 27
-#define EP_WALKABLE_UNDER 28
-#define EP_PASSABLE_OVER 29
-#define EP_PASSABLE_THROUGH 30
-#define EP_PASSABLE_UNDER 31
-
-/* values for runtime properties (non-storable) */
-#define EP_WALKABLE 32
-#define EP_PASSABLE 33
-#define EP_PLAYER_OVER 34
-#define EP_PLAYER_INSIDE 35
-#define EP_PLAYER_UNDER 36
-#define EP_DIGGABLE 37
-#define EP_COLLECTIBLE 38
-#define EP_OVER_PLAYER 39
-#define EP_ACTIVE_BOMB 40
-#define EP_BELT 41
-#define EP_BELT_ACTIVE 42
-#define EP_BELT_SWITCH 43
-#define EP_SP_ELEMENT 44
-#define EP_HAS_CONTENT 45
-#define EP_TUBE 46
-
-#define NUM_ELEMENT_PROPERTIES 47
+
+/* values for special configurable properties (depending on level settings) */
+#define EP_EM_SLIPPERY_WALL 25
+
+/* values for pre-defined properties */
+#define EP_PLAYER 26
+#define EP_CAN_BE_CRUMBLED 27
+#define EP_CAN_MOVE 28
+#define EP_CAN_PASS_MAGIC_WALL 29
+#define EP_SWITCHABLE 30
+#define EP_DONT_TOUCH 31
+#define EP_ENEMY 32
+#define EP_DONT_GO_TO 33
+#define EP_CAN_EXPLODE 34
+#define EP_BD_ELEMENT 35
+#define EP_SP_ELEMENT 36
+#define EP_SB_ELEMENT 37
+#define EP_GEM 38
+#define EP_FOOD_DARK_YAMYAM 39
+#define EP_FOOD_PENGUIN 40
+#define EP_FOOD_PIG 41
+#define EP_HISTORIC_WALL 42
+#define EP_HISTORIC_SOLID 43
+#define EP_BELT 44
+#define EP_BELT_ACTIVE 45
+#define EP_BELT_SWITCH 46
+#define EP_TUBE 47
+#define EP_KEYGATE 48
+#define EP_AMOEBOID 49
+#define EP_AMOEBALIVE 50
+#define EP_HAS_CONTENT 51
+#define EP_ACTIVE_BOMB 52
+#define EP_INACTIVE 53
+
+/* values for derived properties (determined from properties above) */
+#define EP_ACCESSIBLE_OVER 54
+#define EP_ACCESSIBLE_INSIDE 55
+#define EP_ACCESSIBLE_UNDER 56
+#define EP_WALKABLE 57
+#define EP_PASSABLE 58
+#define EP_ACCESSIBLE 59
+#define EP_SNAPPABLE 60
+#define EP_WALL 61
+#define EP_SOLID_FOR_PUSHING 62
+#define EP_DRAGONFIRE_PROOF 63
+#define EP_EXPLOSION_PROOF 64
+
+#define NUM_ELEMENT_PROPERTIES 65