The objective of the present article is to explore differences and similarities between cognitive diagnostic assessment (CDA) and evidence-centered game design (ECgD) in the service of intentional hybridization. Although some testing specialists might argue that both are essentially the same given their origins in principled assessment design and equivalency of measurement models, this view misses differences in their focus and operationalization. Given the strengths of both CDA and ECgD, there is motivation to consider ways in which each can deliberately inform the other. The intentional hybridization of CDA and ECgD has, at least in principle, significant advantages to produce a stronger offspring than either parent alone. The article includes four sections: (1) conceptual differences between CDA and ECgD, (2) conceptual similarities between CDA and ECgD, (3) challenges with CDA and ECgD, including narrowness of cognitive models, fidelity with learning, ocean of data, sensitivity to diverse learners, reliance on multidimensional psychometric models, and how hybridization may help, and (4) implications for educational assessment in the twenty-first century around the globe.