In the Niayes region, part of Senegal’s drylands, population growth, extractive activities, and irrigated agriculture, with a background of climate change, lead to the depletion of natural resources on which people depend for their livelihood. We assume that an approach combining prospective analysis and the development of a game will enable stakeholders to move from projecting into the future to planning concrete actions. Regarding first the territory as a Common to study prospective, we then consider water resources as the key Common (CTFD 2017) around which the main issues are articulated in order to develop a game that will be an intermediary phase to imagine freely the actions to implement. The first step consisted in exploring possible contrasted futures of the Niayes up to 2040. We conducted a foresight exercise involving fifteen local experts. They established a collective diagnosis of past and present dynamics of the Niayes, that permitted to identify 42 factors of change. They then conducted a structural analysis of these factors to select 6 related driving forces, including the groundwater resource. They imagined their alternative plausible states in 2040 and built scenarios based on coherent combinations of these states. From each of the six final scenarios, the expert established a path of actions to connect them with the present situation of the Niayes (Camara et al. 2019). The actions were numerous and covered different sectors, however, they were not precise enough to concretely design specific strategies. For instance, action concerning water resources was no more precise than “having good water management”. In order to develop concrete strategies from this general action of water management, we developed a prototypal game board with local and national experts using à ComMod Approach (Barreteau et al. 2003). Our game session objectives, was to propose a virtual arena that allows the players (4, 5 or 6 players + the public) to i) perceive the scarcity of the resource ii) the influence that each one can have on it iii) collectively they can find a way out of the tragedy of the commons. The game board integrates in an original way a representation of the water table containing real water that each player will have to draw from. The game approach allows them to explore and understand what type of local and/or global regulations they can put in place locally to influence the state of the resource (Le Page et Perrotton 2017). We imagined being able to play several boards simultaneously to collectively explore changes of scale in the rules of governance (exploring the concept of the groundwater committee).