This paper examines the ways in which rebel groups seek to establish social contracts with civilians under their rule. Many studies assume that the rebel social contract is primarily a material exchange between rebel rulers and citizens. We argue that beyond the material, rebel social contracts also express ideological and normative commitments of rebel groups and civilians. The social contract is not just a vertical arrangement, defining state-society relations. It also entails horizontal dimensions, structuring the way citizens engage with each other, and external dimensions, defining how a rebel government relates to the international community. We compare the Islamic State and Rojava (Western Kurdistan), two cases of rebel governance to emerge from the civil wars in Syria and Iraq. Islamic State and Rojava faced similar challenges of maintaining their political control over ethnically and politically fragmented populations. Yet their visions of the social contract, described in official propaganda and evidenced from the construction of governing institutions, differ radically. We show that the Islamic State and Rojava demonstrated marked differences in the vertical, horizontal, and external dimensions of their rule. We argue that these differences are partially attributable to the ideological commitments of the two organizations and their divergent understandings of what constituted a just and desirable social order.