In the past, the rule of law was largely overlooked by sociologists and other social scientists. However, recent years have seen an increasing number of empirical studies of the rule of law. I survey that diverse literature and identify three generations of empirical research, each based on a different approach: (a) the rule of law in action, (b) the rule of law index, and (c) the living rule of law. These studies give us a detailed, but often sobering, view of the rule of law in the real world. I critically review the emerging field and discuss challenges for future research. Developing a more coherent social science of the rule of law is important because it helps us to understand that the rule of law is defined not only by formal institutions and legal documents but also by the place of law in people’s everyday lives.