Is the rule of recognition really a duty-imposing rule?

According to a persistent assumption in legal philosophy, the social rule at the foundation of a legal system (the Rule of Recognition) serves both an epistemic and a duty-imposing function. Thus, some authors have claimed that it would be a formidable problem for legal philosophy to explain how such social rules can impose duties, and some have taken it upon themselves to show how social practices might just do that. However, I argue that this orthodox assumption about the dual function of rule of recognition is ill-founded. Contrary to the orthodox view, we have no good reasons to ascribe more than an epistemic function to the rule of recognition. Accordingly, the norms deriving immediately from the rule of recognition are no different than those entailed by other epistemic, grammatical or syntactic norms. Consequently, accounts of the normativity of law need not explain how social practices like conventions or plans might impose duties on the officials of a legal system.