How do video games affect mental health? A significant research literature has emerged to address this question, yet reviews routinely report conflicting or null results. This has been attributed to insufficiently precise measurement and weak theory. Here, we propose that poor specification of the putative causes (video games) and effects (mental health) contributes as well. Drawing on self-determination theory and affective science, we motivate and present the Basic Needs in Games (BANG) model of video game play and mental health. The model delineates mental health outcomes of interest, proposes how video games affect these outcomes through satisfaction or frustration of basic psychological needs, and identifies boundary conditions and moderators. At a minimum, the model provides a structure for organizing existing work. In the best case, it may serve as a useful tool for generating novel, testable predictions.