Cities with a car-oriented mobility system are significant consumers of energy and require drastic transformations in their structure and function to minimize their harmful impacts on environment and people and to achieve sustainability goals. To promote such sustainable transformations, municipal administrators need to act as change-agents. Because municipal governments are often not agile organizations, they tend toward incrementalism even in the pursuit of transformational goals. Therefore, there is a need in municipal governments to build individual transformative capacity so that municipal administrators can design, test, and implement plans, projects, and policies that are capable of transforming cities toward sustainability. This research presents a game-based workshop, “Stadt-liche Ziele” (AudaCity), that uses a backcasting approach to make municipal administrators build a sustainability strategy. I conducted a pilot study to test the effects of the game on municipal administrators’ confidence in their own ability and power to implement sustainability actions, a key determinant of transformative capacity. Five municipal administrators from Lüneburg, Germany, working on mobility issues, participated in a three-hour-workshop playing the game. Interviews and questionnaires were used before and after the workshop and participants’ contributions during the event were recorded to explore collective changes in confidence. Results indicate that the game increased participant confidence by rewarding collective success, breaking down an ambitious goal into achievable tasks, and acknowledging how administrators’ current actions already contribute to the goal.