In this chapter, we concentrate on geogames for change that enable the cocreation of cities. We introduce theoretical foundations of serious geogames for urban planning and the concepts of playfulness in civic engagement. Two case studies include the serious geogames Geodesign Card Game and GeoMinasCraft. They represent examples of how games can be implemented in a sustainable and participatory urban planning process engaging that engages children and youth. We demonstrate their main functionalities that can be used in urban planning processes, including virtual interaction, experimenting, exploring, designing, learning, communicating, negotiating and consensus building. We present the gameplay of these two selected geogames for change as implemented for the first round of tests with children and youth. We then summarise the main functions of these games and associate them with the phases of sustainable urban planning processes. The planning process was proposed by UN-HABITAT in order to stimulate sustainable planning practices in municipalities. We summarise the main findings and conclude the article with observations related to the game design and implementation of geogames for change in urban planning processes.@en