Designing Audience Interactive Performance: The Theatre Engine Approach to Meaningful Interaction aims to amplify and encourage collaborative interplay in performance by unpacking the research methods, concepts, and adventures of Theatre Engine productions.A framework for meaningful interaction in performance is provided through an examination of the research inquiry, successes, and challenges of five longitudinal Theatre Engine projects. Integrating theatre, music, dance, media arts, and technology, this book offers behind-the-scenes analyses of audience interactive performance. It identifies the need for human connection amid current societal shifts towards isolation and artificiality. This exposition introduces performing arts traditions, innovations, and trajectories that impact the field. Tools for iterative design are presented, including the key concepts of intention, invitation, play, and scaffolding. The approaches and content are customizable for various individual artistic practices and endeavors.This text is written for college students and practitioners who have an interest in interactive, interdisciplinary, and experimental arts production. Artists, designers, and scholars will find useful perspectives and anecdotes from our laboratory-style investigation of participatory design. Readers are invited to implement and adapt the methods and tools for their own creative pursuits.