Popper’s suggestion of taking methodological norms as conventions is examined from the point of view of game theory. The game of research is interpreted as a game of persuasion, in the sense that every scientists tries to advance claims, and that her winning the game consists in her colleagues accepting some of those claims as the conclusions of some arguments. Methodological norms are seen as elements in a contract established amongst researchers, that says what inferential moves are legitimate or compulsory (...) in that game. Norms are classified in three groups: rules of internal inference , entry norms , and exit norms . It is argued that the value of a set of norms depends on how efficient they are in leading a scientific community to accept claims ranking high in a consensuated scale of epistemic value, and in giving each member of the community a reasonable expectation of winning some games. (shrink)