A Plan-Based Formal Model of Character Regret

Martin Martinelli, Justus Robertson

Abstract: Regret is an important emotion in narrative. It is often built into backstories, influences character arcs, and motivates action. Regret is also an important emotion for interactive stories. While linear narratives allow audiences to empathize with and understand characters through their feelings of regret, an interactive context allows participants to feel regret about their own actions and influence on events. A formal model of regret will allow automated interactive storytellers to identify and generate situations where characters, including the participant, feel regret about an action or outcome. To this end, we introduce a formal narrative planning-based model of regret based on character goals and choice. Using our model, we show how character regret is identified in the context of an example dilemma. Finally, we enumerate and discuss types of regret the model has not yet formalized.