Is virtual reality real? The very term invites an ontological investigation and classification. This book addresses the question of the reality of virtual reality from three different perspectives. The starting point of the discussion is David J. Chalmers' virtual realism, which portrays virtual reality as a serious form of reality. Building on Chalmers, the aspect of agency and the feeling of presence in virtual environments is examined separately. Using J. J. Gibson's theory of affordances, it is argued that virtual reality constitutes a real environment because it contains affordances. In a final step, an attempt is made to justify the reality of virtual reality based on its placement within selected, established ontological concepts.