A good instructional game, like many good commercial games, should be built around what the author calls "authentic professionalism." In such games, skills, knowledge, and values are distributed between the virtual characters and the real-world player in a way that allows the player to experience first-hand how members of that profession think, behave, and solve problems. The purpose of this article is to argue that good commercial video games are designed around a good theory of learning--one supported by current research in cognitive science, the science that studies human thinking and learning. After a brief discussion of learning theory and commercial gaming, the author gives an example of how a good video game can engage deep learning, and he closes with a discussion of the implications of his claims for the creation of good instructional video games.