Communicating complex urban problems in an understandable way is not an easy task. This problem is particular true for young adults living in urban areas; it isn’t easy to keep them engaged. However, play!UC is a project with the solution to this problem. It understands that young adults, unlike the older generation, are immersed in the world of games and game playing. It comes very naturally to them. Play!UC understands this and seeks to combine participatory processes with serious games in a co-located setting. Specifically, the project explores how game mechanics can be used to motivate young adults into making informed decisions which have an impact on their urban carbon footprint. The project will achieve this by investigating both existing games and novel game based approaches. play!UC strives to create a well-tested game mechanics toolbox, which can serve as a resource for participatory game-based urban development scenarios. The project will be conducted in the cities of Genk, Belgium; Groningen, the Netherlands; and Vienna, Austria.