Although fairness rules provide a basis for conflict resolution, social and psychological processes can lead people to use these rules flexibly to allow their own groups to compare favorably relative to other groups. In two studies, we examined the expression of such ethnocentric fairness in the context of the Olympic Games. Participants rated the fairness of different methods of determining relative rankings of countries’ performances. Results showed that participants used fairness rules flexibly in ways likely to enhance the relative standing of their own country. Thus, even in this context of normative intergroup harmony, fairness rules can be a basis for intergroup conflict. We conclude that fairness rules are best understood as dynamic constructions reflecting the realities of social life and identity-related processes involved in negotiating that social life.