Determination of the result of actions (either player- or game-initiated) and the delivery of feedback. In a typical game loop, players perform an action, the results are determined according to game rules, and the game world is updated. Shooting at an enemy, the resultant success or failure, and that enemy losing health and updating their own actions (or dying) is one example of a loop. Loops can be isolated or interwoven with others.
The interactions between game loops can lead to intentional or unintentional effects in gameplay which, in the case of good design, allows for repeatable dynamics. Loops can allow players to experiment with and learn from a game world by analysing the feedback from their actions. Because loops deal with the interactive cycle, they are a fundamental aspect of gaming not shared by passive mediums.
“Missed shots in Wolfenstein are particularly unsatisfying because they represent what we imagine to be an open loop. Nothing happens, and it makes us uncomfortable compared with the very definite explosion of gore gifted to us when a bullet hits its target.”