Exposed to increasing levels of uncertainty, the planning model is facing a crisis that affects its theories as well as its methods and tools. In relation with varying structures of governance, some unidentified forms of territories appear, which support new methods of action. By working four years at a French General council, I could approach the planning projects that he managed from within and develop a perspective in which interactions and process of sharing appear to play a central role. Patterns and themes designed by these interactions can be associated to an improvisational action model. Generally considered in a pejorative way, I propose to see improvisation as an efficient way of building common identities and goals and coordinate action between actors. Observing the project managers practices drives to underline a capacity to listen, to build trust, and to foster a special commitment within a logic of giving and belief, which guarantee mutual exchange and active contribution to the project.