By weaving fictional narratives and problem solving into everyday life, alternate reality games (ARGs) may be able to fill gaps left by traditional studies in the behavioral and social sciences. Researchers are exploring new ways to address concerns such as ecological validity, inconsistent replication, and recruitment of large and diverse sample populations. ARG-based research design, using familiar tools and multimedia venues to engage players in meaningful interaction within complex near-real-world environments, offers methods that can make a difference. This book examines the potential strengths of ARG-based social science research, the challenges that remain to be overcome, and potential starting points for testing these possibilities.