This article is conceived as a dialogue between a jurist and an ethnologist about the treatment of risk in sport. It shows how the law treats the question in the face of the evolution of sports practice and of juridical norms aiming at determining the responsibilities and taking care of the injury. By taking more into account the respect for the « rules of game » in each sport discipline, the law seems to consider risk acceptation as a non valid juridical criterion. This is partly due to the fact that the charge of risk is progressively shifted from the individuum to the group – such as the sports association. But then, what about the exercise of the free will of individuums and the resulting responsability ?