Sentence and construction types generally have more than one pragmatic function. Impersonal deontic declaratives such as ‘it is necessary to X’ assert the existence of an obligation or necessity without tying it to any particular individual. This family of statements can accomplish a range of functions, including getting another person to act, explaining or justifying the speaker's own behavior as he or she undertakes to do something, or even justifying the speaker's behavior while simultaneously getting another person to help. How is an impersonal deontic declarative fit for these different functions? And how do people know which function it has in a given context? We address these questions using video recordings of everyday interactions among speakers of Italian and Polish. Our analysis results in two findings. The first is that the pragmatics of impersonal deontic declaratives is systematically shaped by (i) the relative responsibility of participants for the necessary task and (ii) the speaker's nonverbal conduct at the time of the statement. These two factors influence whether the task in question will be dealt with by another person or by the speaker, often giving the statement the force of a request or, alternatively, of an account of the speaker's behavior. The second finding is that, although these factors systematically influence their function, impersonal deontic declaratives maintain the potential to generate more complex interactions that go beyond a simple opposition between requests and accounts, where participation in the necessary task may be shared, negotiated, or avoided. This versatility of impersonal deontic declaratives derives from their grammatical makeup: by being deontic and impersonal, they can both mobilize or legitimize an act by different participants in the speech event, while their declarative form does not constrain how they should be responded to. These features make impersonal deontic declaratives a special tool for the management of social agency.