This chapter reviews a rapidly growing body of empirical evidence on the effectiveness of using video and computer games to provide instruction. Evidence of their effectiveness is drawn from existing results and data. The topics covered here are transfer from computer games to external tasks, enhancing cognitive processes, guidance and animated agents, playing time and integration with curricular objectives, effects on game players, attitudes toward games, cost-effectiveness, and, finally, the use of games for evaluation. Areas where the evidence base is particularly weak are identified in the discussion section. Findings and recommendations for the design of games used in instruction are summarized in a table. The chapter concludes with a call for development of tools and technology for integrating the motivating aspects of games with good instructional design. People do learn from games. Missing are generally effective design processes that ensure that learners will acquire the specific knowledge and skills the games are intended to impart.