DOI: 10.1145/1057270.1057289This book is the first attempt to bridge the current gap between artificial intelligence (AI) research in academia and computer-game development in industry. The book bridges the gap successfully. The author uses FEAR (Flexible Embodied Animat 'Rchitecture), which is an open-source project integrated with a commercial first-person shooter (FPS) game, to analyze, implement, test, and evaluate various AI approaches to various behavioral tasks for nonplayer characters (NPCs). The tasks start with low-level obstacle-avoidance and progress to high-level character emotions; each task with its own part in the book.] Each part is structured into chapters and follows a standard schema: the problem is analyzed, potential mechanisms (including AI) are discussed informally, details of the selected approach are outlined formally, an implementation is provided, the approach is evaluated (primarily visually) through simulation, and finally the advantages and disadvantages of the proposed approach are discussed.