Launcher-Door Trick

The launcher-door trick is a piece of tech created by Symplectic in Carlstlemania: Music of the Mind. The basic premise of this tech is that when there are two launchers with a door between them, it appears that there is only one door, but another door can be hidden under one of the launchers, and if the launchers slide over by a tile, that second door will be shown instead of the first one, making a door appear to lead to two different places. It is important that the distance between the walls and the launchers does not make this look obvious, which is easy to accomplish in a long room. When done well, this is useful for converting a state twice twice into a room twice twice, though it can also be done with twice once.