Over the past 20 years, instructional designers in the Learning Games Lab at New Mexico State University have developed a design model for game development that brings researchers, educators, and game developers together throughout the design process. Using this approach, game developers and content experts (a) work collaboratively to ensure educational goals and outcomes are appropriate for the learner and the learning environment, (b) immerse themselves in both content and game design, and (c) test extensively throughout development with members of the target audience. In this chapter, the authors describe the model as it was used in development of several math games during a four-year development cycle for the Math Snacks project. They discuss the implications of this approach for the creation of other educational games or suites of games and share recommendations for expansion of the model to other developers.