Book excerpt: Fifty Key Improv Performers highlights the history, development, and impact of improvisational theatre by highlighting not just key performers, but institutions, training centers, and movements to demonstrate the ways improv has shaped contemporary performance both onstage and onscreen. The book features the luminaries of improv, like Viola Spolin, Keith Johnstone, and Mick Napier, while also featuring many of the less well‐known figures in improvisation who have fundamentally changed the way we make and view comedy – people like Susan Messing, Jonathan Pitts, Robert Gravel, and Yvon Leduc. Due to improv’s highly collaborative nature, the book features many of the art form’s most important theatres and groups, such as The Second City, TJ & Dave, and Oui Be Negroes. While the book focuses on the development of improvisation in the United States, it features several entries about the development of improv around the globe. Students of Improvisational Theatre, History of Comedy, and Performance Studies, as well as practitioners of comedy, will benefit from the wide expanse of performers, groups, and institutions throughout the book.