If we intend to teach through educational media, we also have to teach about those media. This article explores the implications of this perspective for the use of computer games in the classroom. It seeks to explain why and how teachers might teach about computer games as a medium in their own right, just as they teach about film or television or literature; and it argues that such teaching should not be confined to the critical analysis of existing games, but should also involve enabling students to create their own. The first part of the article provides a broadly theoretical discussion of the notion of "game literacy", on which our approach is based. We argue that this notion needs to address both the defining characteristics of games and the elements they share with other media; and that it needs to incorporate the social practices and contexts within which games are played. The second part of the article explores these issues further through a discussion of the authors' own research in UK schools. It considers the kinds of learning and literacy at stake in the game productions of a group of 12/13-year old students, and the cultural models on which they drew. The article concludes with a brief discussion of the implications of this approach for educational practice and policy. (Contains 4 figures.)