Policymaking processes for sustainable development are often complex and require stakeholders to think in systems. Since games can be considered as playful systems, this chapter aims at providing a systematised review of games design as a policymaking method and approach to help stakeholders think in complex situations. We first provide a comprehensive literature review in the field, by merging both games design models and psychological factors crucial for policymakers. We utilise this conceptual model to undertake a content analysis of six (n = 6) existing games designed for policymaking and sustainable development. Our findings show that in general, these games provide a common space for diverse players to learn from each other via co-production. We have also found that the games provide an opportunity for players to empathise with different characters and that player choice has a more substantial role in gameplay. The contributions of this chapter are twofold. First, we have conducted a literature review that informed a conceptual framework that combined game design principles with psychological factors in co-production and policymaking. Second, we have applied this model via the analysis of existing games to illustrate specific strategies behind games design. We expect that this chapter can become a starting point for researchers, designers and practitioners interested in utilising games in policymaking for sustainable futures.