Late commitment: virtual story characters that can frame their world

Our long-term aim is to build virtual agents that can partake together with human interactors as characters in a story, which emerges from their interactions wich each other and with the story world (the emergent narrative approach). Improvisational theatre -- as a real-life example -- suggests an extension of the current approach to emergent narrative: the event sequence of a story does not emerge based on a fixed story world setting, but the event sequence and the story world setting underlying it, emerge together. We propose a model of this idea, which we call late commitment, meaning that choices about aspects of the story world setting are delayed until they become useful for story progression. We discuss possibilities and issues concerning the use of this technique in the context of action planning and goal adoption for character agents