PLATO's plasma panels were well suited for gaming even though the bandwidth was rather low. And using the communication features it was also possible for the games to go online. Many popular MMOs were developed during the 1970s and 80s such as Empire, Airfight, Panther, the original Freecell, and several games inspired by Dungeons and Dragons. First person shooters like Doom and Quake made their appearance on the PLATO systems. Avatar was PLATO's most popular game and was the world's first MUD and has over a million hours of use.
Although mainly designed for educational purposes the most enduring legacy of the PLATO systems was the online community created by its communication features. PLATO Notes was one of the world's first online message board and by 1976 PLATO had spawned a variety of tools for online communication, including email, chat rooms, instant messaging, remote screen sharing, and emoticons.