Digital cognitive games (DCGs) are games whose primary purpose is to mediate (i.e., support, develop, and enhance) cognitive activities such as problem solving, decision making, planning, and critical reasoning. As these games increase in popularity and usage, more attention should be paid to their design. Currently, there is a lack of design processes that provide both structure and room for creative development of such games. This article presents a preliminary process for design of DCGs. The design process involves the application of cognitive toys and isomorphism. Using this process, designers will use a cognitive toy to be inspired to develop DCGs, and isomorphism is intended to help them produce a diverse set of DCGs based on the same cognitive toy. The resulting DCGs will have deep similarity with the original cognitive toy but are unique in terms of their surface features. (Contains 9 figures, 4 tables and 2 notes.)