Controlling NPC behavior using constraint based story generation system

Modern technology has made it possible to instill greater realism in computer games; however, most of the current game environments still need to better reflect the real world. In particular, most Non-Playable Characters (NPCs) are limited by a restricted range of reactions within the playing parameters of the game, which can be boring for the players. As a result, the players may quickly lose their interest in the game; therefore, methods for both effectively generating and controlling behavior are indispensable. This research describes how NPCs can both adopt a wide variety of behaviors based on their `properties' and `live in the game space' regardless of the player “viewpoint” of the current scene in play. Based on our research, we have implemented a system which is written as markup language that generates the behaviors of NPCs. By evaluating the generated behaviors from our system, we verify that it has a positive effect in terms of the generation of better quality NPCs.