Mediating the Tension between Plot and Interaction

When building a story-intensive game, there is always the question of how much freedom to give the player. Give the player too little, and he may feel constrained and disconnected from the character he is controlling. Give him too much freedom, and the progression of the story may lag or stop altogether. This paper focuses on our attempt to find a balance between offering the player a high degree of interaction and providing a story-based experience where the player is a key character. Our approach is embedded in our Interactive Drama Architecture (IDA), which includes an omniscient story director agent who manages the player’s narrative experience. The director agent uses a declarative description of the plot to track the player’s progress, detect deviations from the plot, and make directions to supporting characters in the game. Our director is used within a game we have developed, called Haunt 2, which is an extension to the Unreal Tournament engine.