Part I of this Article examines the intersection between procedure and substance and between the rules of civil procedure and civil rights litigation, including the theoretical wisdom and propriety of creating substance-specific procedural rules. Part II examines Rule 15(c) of the Federal Rules of Civil Procedure and the current requirements for relation back, particularly the way in which courts and commentators have approached the meaning of the word "mistake" and the problems this interpretation poses for civil rights plaintiffs. Part III discusses in detail five possible mechanisms for identifying and proceeding against unknown officer defendants under § 1983, including the defects and benefits of each, concluding that the creation and use of a pre-filing discovery mechanism provides the best solution.