Can human rights impose positive duties to act, as well as negative duties constraining action? At first glance there seem to be strong reasons for wishing human rights could impose positive duties - such reasons include the promotion of welfare rights and the positive protection of liberty rights (e.g. police protection against assault). However, any attempt to construct rights-based positive duties threatens to dissolve hallmark features of rights. In this article the duty-properties possessed by uncontroversial rights-based negative duties are comprehensively alysed. Drawing on this alysis, a range of key properties is developed, including 'regime-level right-holder universality' and 'many-to-one directedness', as well as a 'centres of pressure' vision of rights, by which it is argued that positive duties can accord with the keystone commitments of rights-based moral theories. In so doing, a conceptual space for rights-based positive duties is defended.