Video games dominate the landscape on millions of private screens. For a quarter of a century, they have ceased to be the concern of laboratories, military advisors, or subcultures, instead generating and sustaining popular media networks whose revenues overshadow those of Hollywood. Educators are increasingly worried, cultural studies are gradually showing interest, and the first video game museums are emerging. Yet, no one has asked the simplest of questions: Why do video games exist? For video games, as we know them, arrived uninvited and are therefore anything but a given. But what is this strange date, and where is the place where completely heterogeneous devices, bodies, and symbols, long prepared yet suddenly, come together to form a game of an entirely new kind? What kind of knowledge is it that...