Although rules are codified in explicit language, the goals and normative force underlying them remain ambiguous. We argue that people interpret rules in the broader social context where the rule is set. We hypothesize that an authority’s perceived legitimacy—impartiality, competence, and benevolence—affects rule endorsement and compliance through influencing interpretation of the rule’s intent. In an online vignette study with 50 realistic rules that range from very positive to very negative, we found that participants were more likely to endorse and comply with the same rule if it is set by a legitimate compared to an illegitimate authority, independent of the a priori rule’s valence (obtained from independent participants in a norming study). In ongoing work, we are testing the robustness of this effect, probing the potentially distinctive representation of legitimacy from other positive leadership dimensions, and investigating the cognitive mechanisms of how legitimacy shapes norm internalization and voluntary compliance.