Educational games research is a menagerie of different methodologies and paradigms. Mixed results in the literature are difficult to interpret due to the combination of different theoretical frames, different data reporting conventions, and a general focus on proof-of-concept studies. Narrower investigations of specific causal relationships between game properties and outcomes of engagement and learning can provide more specific findings, but require a way to incorporate them into the broader picture of educational games research. In this study, we focus on educativonal games and propose the Model-Master-Transfer (MMT) framework to break down educational game usage into a set of formal sub-processes that can be studied in more depth individually, and specify how such narrow studies can then be assembled to build up a causal model of the underlying effects. The framework is illustrated using different educational examples. The conceptual study contributes a comprehensive framework to the ambiguous research on educational learning using games. Additionally, it provides practical implications for game developers and educators alike.