Complex problem solving and motivation are often argued as the most important benefits of massively multiplayer role-playing online games. However, little empirical research exists to support these assertions. Current research and educational game design theory are insufficient to explain the relationship between complex problem solving, motivation, and games; nor do they support the design of educational games intended to promote motivation and complex problem-solving skills. For the past few years, we have been engaged with design-based research (DBR) to address this gap in the literature. In this chapter, we present the findings of this study in a framework for designing and assessing educational MMORPGs for facilitating learners´ motivation and complex problem-solving skill acquisition. This game design and assessment framework bridges three levels of interactivity that were identified in a series of DBR studies as being crucial for effective educational game design: (1) interface interactivity, (2) narrative interactivity, and (3) social interactivity. In this chapter, we present Interactivity ³ design and assessment framework and discuss the findings of a study that shows the validity of this framework for designing and assessing educational MMORPGs.