5 Decision Making sk a gamer about game AI, and they think about decision making: the ability of a character to decide what to do. Carrying out that decision (movement, animation, and the like) is taken for granted. In reality, decision making is typically a small part of the effort needed to build great game AI. Most games use very simple decision making systems: state machines and decision trees. Rule-based systems are rarer, but important. In recent years a lot of interest has been shown in more sophisticated decision making tools, A