Contrary to assumptions about the aversive effects of competition on achievement motivation, in this study young people saw academic contests as fair. When 136 children and adolescents (ages 6-14) completed structured interviews on fair ways to organize science contests and on the differentiation of skill and luck, age-related trends in their conceptions of procedural justice were parallel to their ability to differentiate skill and luck tasks. Differences in the use of contest-specific attributions such as credit allocation, odds of winning, and incentives were central to developing conceptions of procedural justice. Everyone made similar intrapersonal attributions to effort, mood, talent, and interest. Individual competition was judged to be more fair than team competition. Effectiveness was seen as necessary but not sufficient for establishing fairness. Personal harm was not central to developing conceptions of fair contests.