Although computer and video games have existed for fewer than 40 years, they are already serious business. Entertainment software, the entertainment industry's fastest growing segment, currently generates sales surpassing the film industry's gross revenues. Computer games have significantly affected personal computer sales, providing the initial application for CD-ROMs, driving advancements in graphics technology, and motivating the purchase of ever faster machines. Next-generation computer game consoles are extending this trend, with Sony and Toshiba spending $2 billion to develop the Playstation 2 and Microsoft planning to spend more than $500 million just to market its Xbox console [1]. These investments have paid off. In the past five years, the quality and complexity of computer games have advanced significantly. Computer graphics have shown the most noticeable improvement, with the number of polygons rendered in a scene increasing almost exponentially each year, significantly enhancing the games' realism. For example, the original Playstation, released in 1995, renders 300,000 polygons per second, while Sega's Dreamcast, released in 1999, renders 3 million polygons per second. The Playstation 2 sets the current standard, rendering 66 million polygons per second, while projections indicate the Xbox will render more than lOO million polygons per second. Thus, the images on today's $300 game consoles rival or surpass those available on the previous decade's $50,000 computers. The impact of these improvements is evident in the complexity and realism of the environments underlying today's games, from detailed indoor rooms and corridors to vast outdoor landscapes. These games populate the environments with both human and computer controlled characters, making them a rich laboratory for artificial intelligence research into developing intelligent and social autonomous agents. Indeed, computer games offer a fitting subject for serious academic study, undergraduate education, and graduate student and faculty research. Creating and efficiently rendering these environments touches on every topic in a computer science curriculum. The "Teaching Game Design " sidebar describes the benefits and challenges of developing computer game design courses, an increasingly popular field of study