This paper aims to investigate the applicability of Grice's theory of conversational implicatures to legal statutes and other general heteronomous legal acts (while acts of private autonomy are excluded from the scope of the present investigation). After a brief presentation of Grice's theory Sect. 1 and an attempt to adapt conversational maxims to normative discourse -which is assumed to be neither true nor false Sect. 2 -I will survey one of the most convincing arguments against the applicability of conversational maxims to the legal domain, the one based on the (absence of a precise, real) legislative intention Sect. 3 . I will argue that this argument is not decisive, but that, however, conversational maxims do not apply to legislation: as a matter of fact, legal practice does not include Grice's conversational maxims among its conventions Sect. 4 . This inapplicability, which derives from the very nature of the cooperative principles and the maxims, fi ts other peculiarities of legal practice: perhaps the most relevant is what we may call the contextual indeterminacy of legal discourse, a characteristic that is rigidly coupled to its confl icting nature. I will claim that all these features explain why legislation and other general heteronomous legal acts are not special cases of ordinary conversations Sect. 5 .