Character behaviors in computer role-playing games have a significant impact on game-play, but are often difficult for game authors to implement and adapt. We present a behavior model that requires no manual script writing. In this model, behaviors can be interrupted and resumed, they can transition to other behaviors depending on game events, and they can be chosen based on motivations. We have extended the generative pattern approach of ScriptEase to support behaviors. We describe an implementation of this model that generates scripting code for a commercial game, Neverwinter Nights.