The architecture competition is a high point of interaction between very diverse actors, architecture specialists or not. However, is it really an opportunity for exchange and shared learning ? Based on surveys conducted in France and in several European countries on behalf of the French Ministry of Culture, this contribution aims to identify the conditions that foster the interactions inherent to competitions, the possible scope of these exchanges and the rationale behind them. When the competition is a chosen procedure, it is most often perceived as a moment of generating ideas that opens a professional debate and also addresses the general public. When it is mandatory, the competition is guided by another logic : that of ensuring the fairness and transparency of the joint choice of a project and a service provider as well as the legality of the contract concluded with the latter. Depending on the place given by decision-makers to this legal and contractual dimension, the nature and scope of the debates around the competition vary widely. If the legalistic approach dominates, it tends to limit interactions. However if the contracting authority adopts a more open approach to the competition, from programming to the dissemination and capitalisation of its results, it can make a real process of collective deliberation and favour the growth of shared competence.