Computer games are moving in the direction of more dramatic content. Characters in computer games are becoming more autonomous and are increasingly required to display purposeful and emotional behavior and to appear to understand the situation. An alternative to simulating their mental state is to portray it just as a human actor portrays a character. Situated action provides a theoretical basis for understanding how to do this with quite simple agents. In this article we describe a way of organizing systems of interacting agents and a corresponding agent architecture and implementation technology, all based on situated action, and then report our experience of applying this technology to the production of an agentbased game embedded in a published CD-i title.