--- /dev/null
+Emerald Mine doors will fling you to the other side of the door, rather than
+letting you stand on it. If there is *any* object on the other side, the
+player cannot pass through the door. Note that creators may allow players to
+pass to anything walkable under the player object's options.
+
+Gray doors' real colors are kept hidden to the player, making him/her guess
+which color key opens the door.