Although most agree that games can be engaging and that games can be instructive, there is little consensus regarding the essential characteristics of instructional games. Implicit in the research literature is the notion that if we pair instructional content with certain game features, we can harness the power of games to engage users and achieve desired instructional goals. We present an input-process-output model of instructional games and learning that elaborates (a) the key features of games that are of interest from an instructional perspective, (b) the game cycle of user judgments, behavior, and feedback that is a hallmark of engagement in game play, and (c) the types of learning outcomes that can be achieved. We discuss the implications of this approach for the design and implementation of effective instructional games.