The concept of “protocol society” is an invitation to see social structures through the lens of the protocol—a set of voluntary rules governing communication and conduct. Examples include monastic rules, cross-border financial systems, diplomatic rituals, Internet standards, and blockchain contracts. Protocols typically coexist with other kinds of social structures, such as states and markets, and they can be an enabling substrate for those structures, but protocols are not reducible to them. Recognizing the existence of protocol-based social ordering helps reveal underappreciated aspects of historical and present societies. Protocols can also serve as the basis of imagining possible social futures—particularly in the pursuit of societies less dependent on enforcement through state violence.