In 1913, the founding members of Actors’ Equity Association (AEA) drew a clear line between the actors of the legitimate theatre that they sought to organize and other performers, conceived of as non-actors. Since then, theatre and labor relations scholars largely have uncritically viewed AEA as a collective bargaining organization, overlooking how it has continued to determine the very artistic practices that constitute what is and isn’t acting. This presentation discusses immediate and long-term implications for acting (and its others) of AEA’s jurisdictional disputes, rulings, and arbitrations, considering a collection of both little-known cases (e.g. Jumbo, 1935) and infamous ones (e.g. Miss Saigon, 1990) that have fundamentally shaped acting as an artform and occupation.