In this vision paper, we posit ‘game system building’ as a paradigm for game design. Inspired by earlier perspectives on cybernetic art and generative art we consider the creation of dynamic game systems as an artistic practice where the consideration of complex and often unpredictable behavior and effects are as foundational as the individual elements (rules, graphics, characters, UI etc.). The perspective of ‘game system building’ has important implications for the education of designers and games scholars. In this paper, we introduce the paradigm and its lineage and propose an educational approach that reflects ‘game system building’.