This dissertation explores acting in productions directed by Frank Castorf at the Berlin Volksbühne between 1990 and 1994. Castorf’s directorial style has transformed German theater, and continues to have notable influence on European directors today. Until now, however, scholars and critics have attended primarily to the directorial and dramaturgical innovations of these productions, and less to their “actorial” ones. This dissertation not only views acting as the mainstay of “the Castorf style.” It also argues that Castorf’s theater represents a paradigm shift in acting more broadly. Each chapter takes one stage production as the starting point for an investigation into the operations and effects of “Castorfian acting.” Chapter One takes ROBBERS [RÄUBER] (1990) to illustrate how these performances are created in rehearsal. Using archival material and interviews, I draw a picture of Castorf’s rehearsal room as a site of “agonistic” interaction between actor, director, and text that inscribes itself in the actors’ performances as a liminal ontology. Chapter Two shifts from the standpoint of production to that of reception to demonstrate how acting contributes to the Volksbühne’s institutional image as a “disruptive factor” in the public sphere. I show how actors in Clockwork Orange (1993) perform this “disruption,” and how this exposes and animates conflict between actor, audience, and city. Chapter Three demonstrates how the critical work of Castorf’s theater occurs in the performances through techniques of dissociative splitting that enable actors to (re)present multiple characters at once. In Schöller’s Boarding House/The Battle [Pension Schöller/ Die Schlacht] (1994), the actors map constellations of people, events, and attitudes from German history that implicate the country’s theater “stars” in the cultural production of totalitarian ideology. The dissertation concludes with a brief reflection on the role of video in Castorf’s theater and in my own research.