Some questions.

[Saffire]

By setting an action to move, an object will react when a character enters the room that the object is in, but how do I set it to perform an action when a character leaves the room in a certain direction? Also, is there a way to stop the player's movement when that reaction fires?

[Justin]

The move event is sent to both the start room and the destination room. To differentiate between them, you can check what room the character is currently in. If they are in the room, it is the destination.

Stopping the movement via a reaction is not currently possible, but definitely something I'll have to think about.