We present an approach to incorporate interesting and compelling characters in planning-based narrative generation. The approach is based on a computational model that utilizes character actions to portray these as having distinct and well-defined personalities. Well-developed characters have features that enable them to significantly enhance the believability and quality of a story. In this paper we present a computational model aimed at facilitating the inclusion of compelling characters in narratives that are automatically generated by a planning-based system. In this model, personality is operationalized as behavior that results from choices made by a character in the course of a story. This operationalization uses the taxonomy defined in the Five-Factor Model (FFM) (Goldberg 1990) and results from behavioral psychology that link behavior to personality traits (Mehl, Gosling, and Pennebaker 2006). The model focuses on the role that actions performed by characters play over the ...