Facilitated by the ascendance of massive multiplayer online games and virtual worlds, digital game culture has become a part of children's lives over the past few years. By playing these games, children can not only socialize with their regular friends face to face but also establish relationships with other players online. This chapter presents an overview of games and virtual worlds, including defining these terms and how these technologies could be employed to leverage learning. This chapter also addresses the motivational components in games, which is an area of interest for game researchers and educators. Additionally, this chapter includes research in educational and commercial virtual worlds for children as means to identify the educational and motivational outcomes of these technologies. Lastly, the chapter concludes with implications for the use of games and virtual worlds for educational purposes. [For the complete volume, "Educational Media and Technology Yearbook, Volume 39," see ED594284.]