How does making law through private lawsuits differ from making law by other means? That question is especially important where legislators deputize “private attorneys general” as statutory enforcers, from antitrust and securities to civil rights and consumer protection. Yet legal scholars have not offered sustained theoretical or empirical analysis of how private enforcement efforts evolve over the life of a regulatory regime and, in turn, shape the elaboration of legal mandates. This Article begins filling that gap by sketching a pair of competing accounts of “private enforcement’s pathways.” The Article then tests these accounts using original data drawn from a growing and increasingly controversial litigation regime that is fueling intense debate about the quantity, quality, and public control of private enforcement efforts: qui tam litigation under the False Claims Act (FCA). Examining some 6,000 qui tam lawsuits since 1986, the analysis rejects the claim, common among private enforcement’s critics, that the regime’s recent growth constitutes an inefficient “gold rush” of private enforcement activity. Yet the data also support the concern that entrepreneurial private enforcers will relentlessly press law’s boundaries, exploiting regulatory ambiguities in industry-wide lawsuits that public-minded prosecutors would reject, thus driving law down interpretive pathways it would not travel if enforcement were in purely public hands. Mapping private enforcement’s pathways in this way offers fresh perspective on longstanding debate about the merits and demerits of private enforcement of public law and the complex relationship between litigation and democracy, in the FCA context and beyond.