The 21st annual Foundations of Digital Games (FDG) conference invites researchers, educators, and practitioners to submit original research contributions. We welcome submissions in the form of full and short papers, posters, demos, doctoral consortium applications, and proposals for panels, competitions, and workshops. FDG invites contributions from within and across any discipline committed to advancing knowledge on the foundations of games, including computer science, engineering, mathematics, natural sciences, humanities, social sciences, arts, and design.