This research exams referee's judgment activity apart from legal formalism which reduces it to rule application. Its aim is to study experienced rugby referee's judgment act through anthropological and phenomenological approach. In this way, a new methodology has been elaborated and 7 referees, which officiate in French Rugby Federation's National 1 Championship during 2000/01 and 2001/02 seasons, have taken part in this research. Results show three kinds of judgement act: (1) "act-judgement", judicatory moment, which builds itself progressively in referee's dynamic relation to players's acts, (2) "fact judgment" in which a reality in its relation to a rule appears evident in a perception, (3) "deliberate judgement" which results to finished event's conscious reconstruction. Judgement act is neither a reaction to an environment's configuration, nor a standard way to grasp one specific passage of play. As judgement act is descriptive and performative, it is possible to conceive that referee co-constructs the course of the play bringing players in his rugby world. The rules of the game are the possibility of these co-construction: there establish the referee power on the play, and there constitute the necessary common values between referee and players to coordinate themselves.
