Multi-player

Online text-based role-playing games involve many players using some type of text-based interface and an Internet connection to play an RPG. Games played in a real-time way include MUDs, MUSHes, and other varieties of MU*. Games played in a turn-based fashion include play-by-mail games and play-by-post games.
Massively multi-player online role-playing games (MMORPGs) combine the large-scale social interaction and persistent world of MUDs with graphic interfaces. Most MMORPGs do not actively promote in-character role-playing, however players can use the games' communication functions to role-play so long as other players cooperate.^[29] The majority of players in MMORPGs do not engage in role-play in this sense.^[30]
Computer-assisted gaming can be used to add elements of computer gaming to in-person pen and paper role-playing, where computers are used for record-keeping and sometimes to resolve combat, while the participants generally make decisions concerning character interaction.

Gamemaster

One common feature of many RPGs is the role of gamemaster, a participant who has special duties to present the fictional setting, arbitrate the results of character actions, and maintain the narrative flow. In pen-and-paper and live action RPGs the GM performs these duties in person. In video RPGs many of the functions of a GM are fulfilled by the game engine, however some multi-player video RPGs also allow for a participant to take on a GM role through a visual interface called a GM toolkit, albeit with abilities limited by the available technology.