Constraints are boundaries that keep the player within the landscape. All gaming spaces need constraints, as there are limitations, both technical and practical, on the size of a game world. Constraints need to occur with a naturalistic presentation to avoid frustration (Rollings and Adams 2003). For example, constraints such as invisible walls and bottomless pits lack verisimilitude and remind the player of the designer. Such devices often deplete the player’s energy or lives on contact and so can make him/her feel that s/he is being punished for expressing individuality.