Abstract: The misdemeanor system is a powerful governance tool. Comprising the vast bulk of the U.S. criminal process, it exerts enormous influence over the disadvantaged populations that are its primary clientele, and profoundly shapes the general character of American criminal justice. Characterized largely by speed, informality, and law enforcement discretion, the petty offense process generates millions of criminal convictions and burdensome punishments in ways that depart significantly from the standard due process model of adversarial adjudication, with special implications for the poor and people of color. This article provides a theoretical overview of the petty offense process and its legal and institutional structures, and explains its sociolegal significance for the criminal system as a whole.