Competences play a significant role in normative settings. On principle, a competence can be conceived of as a capacity to validly change existing normative relations and positions. One of the most central questions connected to the concept of competence concerns its relation to legitimacy. Does having a competence imply being permitted to exercise it? After having introduced acts of competences as normative acts, the main part of the paper will be dedicated to this question. The prevalent attitude in the literature (...) is a negative one. According to that view, a competence is to be understood as an alethic capacity and not as a deontic one. The arguments put forward to justify this negative answer will be reconstructed and rejected. A deontic concept of competence will be favoured. In the last part, the rejection of an alethic concept of competence will be supplemented by pointing out its problematic implications for other fundamental concepts. This will be done by disclosing some internal difficulties of Hohfelds famous approach. Strangely enough, these difficulties have not been discussed so far. (shrink)