This paper highlights one of the main characteristics of French social field experiments: a triangular game involving the State, local partners and experts. Firstly, it focuses on the consequences of the State’s ambiguous relationship with local authorities as regards social field experiments. This difficulty constitutes a recurring impediment for partners to setting the goals of field experiments. Then, the paper points out a dual tendency of the FEJ (the national experimental fund for youth). The first one is a thematic shift from youth to issues that only concern educational problems: even though the FEJ originally emphasized the importance of promoting bottom-up innovative actions that try to cope with numerous social issues connected with youth, it ended up dealing with educational issues. The second tendency concerns the FEJ’s evolution, which became part of the State apparatus dedicated to top down policies. Finally, this article examines the core of the triangular game, namely the replication on a larger scale of the field experiments. It shows that this nodal point remains a blind spot for most of all these embedded partners.