Cities are becoming the locus of climate change policy and planning, both for mitigating greenhouse gas emissions and adapting to the impacts of climate change. These actions involve a number of trade-offs, including densification of the urban structure, concerns over social equity and the proper use of green infrastructure for adaptation. Many of these impacts are difficult to quantify and their interdependencies are often challenging to comprehend. There are a number of outstanding gaps in knowledge both in research and in practice in relation to how decisions are made between adaptation and mitigation strategies and what kinds of negative and positive synergies can be identified between them. This paper explores how social games can help people to understand the trade-offs between mitigation and adaptation measures in an urban environment and examines the possibilities of using social gaming as a research method. Data was collected from Denmark, Finland and the US through organized gaming sessions. The conclusion of the study is that social games are a promising method to understand complex planning problems.