Slurs are derogatory words and they are used to derogate certain groups. Theories of slurs must explain why they are derogatory words, as well as other features like independence and descriptive ineffability. This paper proposes an illocutionary force indicator theory of slurs: they are derogatory terms because their use is to perform the illocutionary act of derogation, which is a declarative illocutionary act to enforce norms against the target. For instance, calling a Chinese person “chink” is an act of derogation to enforce racist norms that license exclusion of the Chinese, deny their rights to dignity, etc. The contribution of this paper is twofold. First, it offers a more comprehensive explanation of the features of slurs than earlier speech act approaches. Second, it provides a theory that is immune to the problems faced by existing theories, such as wrong predictions of truth-conditions, explaining unacceptability to non-bigots, and explaining slurs against the dominant groups.