Nowadays, many people enjoy playing games in computer. In this kind of game, people often meet NPC (Non Player Character). It is the virtual character in simplified form of real player and exits in most of current computer games. Various NPCs add the reality and atmosphere of the game as well as help players. There are several techniques to embody NPC, but developers generally use AI technique. This paper discusses some artificial intelligence techniques used in game contents. Especially this paper focuses on the AI techniques used in computer games in terms of the two main approaches, symbolic approach and sub-symbolic approach.