An invisible wall is a boundary in a video game that limits where a player character can go in a certain area, but does not appear as a physical obstacle. The term can also refer to an obstacle that in reality could easily be bypassed, but doesn't allow the character to jump over it within the game, such as a mid-sized rock or short fence. In 2D games, the edge of the screen itself can form an invisible wall, since a player character may be prevented from traveling off the edge of the screen.