Old Fadama in Accra, Ghana, is a vast informal settlement. A legalistic approach by successive governments has meant a near-absence of statutory institutions and the emergence of alternative public authorities. These endeavour to provide the area with a range of basic public services to solve the area's serious developmental challenges. Through processes of informal negotiation residents establish rights and social contracts that underpin and define what will constitute ideas of state and law. At the same time, self-governance emerges while relations with statutory institutions shift back and forth between vilification, tacit acceptance, and productive cooperation. The article contributes to studies of governance in informal urban settlements on two fronts. First, it shows how informal arrangements lead to the provision of basic public services and influence the workings of formal institutions of government. Second, it challenges facile understandings of large-scale informal settlements as generally chaotic, lawless or subversive.