The growth of state interventionism, especially in the post-war era, has been associated with the proliferation of legal innovations. This paper examines the development of novel hybridizations of civil and criminal forms, developed largely to facilitate state regulation. Such hybrids, referred to here as civil offenses, combine civil proceedings, often referred to as prosecutions, with notions of convictions for which penalties are imposed. The advantages accruing to the state from such “ambiguous” forms include favorable standards of proof, rules of interpretation, extending responsibility, retroactivity, suspension of mens rea, and a wide array of novel sanctions.