Invisible Wall

An invisible wall or invisi-wall is a video game term for a boundary that limits where a player can go in a certain area, but doesn't appear in-game as any kind of visible obstacle, or as an obstacle that in reality could easily be bypassed, such as a mid-sized rock or short fence. In 2D games, the edge of the screen itself can form an "invisible wall", in that a character in play may be prevented from travelling off the edge of the screen. In 3D games, invisible walls are used similarly to prevent a player leaving the gameplay area. This is often done in preference to using a more visible boundary, as this can reduce the realism of the environment.