International audienceFor a few years, Ouessand's island has been in the process of a social restructuration, and in the same time a transformation of the landscapes, more specifically with massive fallow lands. This text describes the construction of a model of interactions between social and environmental dynamics, conducted by a multidisciplinary team. From this prototype, a roles game has been developed in order to assist the consciousness raising and the involvment of all, elected representatives or not. This text also contributes to a reflection on the place of such tools in the context of a dialogue, whose main issue remains the question : "HOW?"L'île d'Ouessant connaît depuis plusieurs années une recomposition sociale et parallèleme...