Nowadays, interactivity often serves as a way to make cultural products more attractive for the audience. Due to the growing popularity of immersive theatre and theatre makers’ interest in digital technologies, interactivity became again a relevant issue in theatre context. However, there is a need to revise the definition of it. Therefore, this article, at first, discusses the boundaries of the term relying on the previous research, later it presents a common perspective on interactivity in theatre as a feature of performance structure and, finally, suggests a new approach to interactivity as an outcome of communication process. According to the latter perspective, creators of performances become only initiators of interactivity and theatre audience are real determiners.