This conclusion presents some closing thoughts on the key concepts discussed in the preceding chapters of this book. The book comprehensively reviews the origins, players, and social dynamics of multiplayer online games (MOG), as well as six major empirical research methods used in previous research to study MOGs. The research methods are observation/ethnography, surveys/interviews, content and discourse analysis, experiments, network analysis, and case studies. It explains that MOGs represent a highly sophisticated, networked, multimedia, and multimodal Internet technology, which can construct entertaining, simultaneous, persistent social virtual worlds for gamers. This comprehensive review of MOG studies has many implications for future directions and sheds light on various opportunities such as cultural studies, education, human–computer interaction, and information science. MOGs not only provide new research opportunities to study emerging game cultures in the virtual world, but also shed light on changes in existing cultures in the physical world.