Generating Ambient Behaviors in Computer Role-Playing Games

To compete in today's market, companies that develop computer role-playing games (CRPGs) must quickly and reliably create realistic, engaging game stories. Indeed, intricate storylines and realism that goes beyond graphics have become major product differentiators. To establish both, it's essential that companies use AI to create nonplayer characters (NPCs) that exhibit near-realistic ambient behaviors. Doing so offers players a rich background tapestry that makes the game more entertaining. Because storylines must come first, however, NPCs that aren't critical to the plot are often added at the end of the game development cycle - if resources are available. To control NPCs' ambient behaviors, many computer games use custom scripts. Story authors must therefore write computer code fragments for the game world's hundreds or thousands of NPCs. Our approach lets game authors use generative behavior patterns to create scripts of complex NPC behaviors and interactions. To build these patterns; they use our publicly available ScriptEase tool, which lets them create game stories using a high-level, menu-driven programming model