What makes games effective for learning? The authors argue that games provide vicarious experiences for players, which then amplify the effects of future, formal learning. However, not every game succeeds in doing so! Understanding why some games succeed and others fail at this task means investigating both a given game's design and the educational context in which it is deployed. Based on their ongoing research, the authors propose concrete and specific ways to enhance the learning potential of play under the "preparation for future learning" model.