Very early on, Niki de Saint Phalle (1930-2002) discovered the theatre as a source of inspiration. She wrote her first play when she was only a young student. Artistic work for the stage proved to be an important field of experimentation for the artist. Fascinated by the possibility of the active participation of the audience, she then wrote the stage play ICH, which was presented in Kassel on the occasion of the 1968 documenta exhibition. This publication demonstrates for the first time to what extent de Sant Phalle was fascinated by the theatre and how this affected her visual art oeuvre.