Although children enact third-party punishment, at least in response to harm and fairness violations, much remains unknown about this behavior. We investigated the tendency to make the punishment fit the crime in terms of moral domain; developmental patterns across moral domains; the effects of audience and descriptive norm violations; and enjoyment of inflicting punishment. We tested 5- to 11-year-olds in the United Kingdom (N = 152 across two experiments, 55 girls and 97 boys, predominantly White and middle-class). Children acted as referees in a computer game featuring teams of players: As these players violated fairness or loyalty norms, children were offered the opportunity to punish them. We measured the type (fining or banning) and severity of punishment children chose and their enjoyment in doing so. Children only partially made the punishment fit the crime: They showed no systematic punishment choice preference for disloyal players, but tended to fine rather than ban players allocating resources unfairly--a result best explained by equalization concerns. Children's punishment severity was not affected by audience presence or perpetrators' descriptive norm violations, but was negatively predicted by age (unless punishment could be used as an equalization tool). Most children did not enjoy punishing, and those who believed they allocated real punishment reported no enjoyment more often than children who believed they pretended to punish. Contrary to predictions, retribution was not a plausible motive for the observed punishment behavior. Children are likely to have punished for deterrence reasons or because they felt they ought to.