A massively multiplayer online game (also called MMOG or simply MMO) is a video game which is capable of supporting hundreds or thousands of players simultaneously. By necessity, they are played on the Internet, and feature at least one persistent world. They are, however, not necessarily games played on personal computers. Most of the newer game consoles, including the PlayStation Portable, PlayStation 3, Xbox 360, Nintendo DS and Wii can access the Internet and may therefore run MMO games.

MMOGs can enable players to cooperate and compete with each other on a large scale, and sometimes to interact meaningfully with people around the world. They include a variety of gameplay types, representing many video game genres.

History

main: History of MMORPGs The most popular type of MMO, and the sub-genre that pioneered the category, is the massively multiplayer online role playing game (MMORPG), which descended from university mainframe computer MUD and adventure games such as Rogue, Dungeon on the PDP-10; and Devious MUD, which later turned into the successful game RuneScape. These games predate the commercial gaming industry and the Internet, but still featured persistent worlds and other elements of MMOGs still used today.

The first graphical MMOG, and a major milestone in the creation of the genre, was the multi-player flight combat simulation game Air Warrior by Kesmai on the GEnie online service, which first appeared in 1986.

Commercial MMORPGs gained early acceptance in the late 1980s and early 1990s. The genre was pioneered by the GemStone series on GEnie, also created by Kesmai, and Neverwinter Nights, the first such game to include graphics, which debuted on AOL in 1991.

As computer game developers applied MMO ideas to other computer and video game genres, new acronyms started to develop, such as MMORTS. MMOG emerged as a generic term to cover this growing class of games. These games became so popular that a magazine, called Massive Online Gaming, released an issue in October 2002 hoping to cover MMOG topics exclusively, but it never released its second issue.

The debuts of The Realm Online, Meridian 59 (the first 3D MMOG), Ultima Online, Underlight and EverQuest in the late 1990s popularized the MMORPG genre. The growth in technology meant that where Neverwinter Nights in 1991 had been limited to 50 simultaneous players (a number that grew to 500 by 1995), by the year 2000 a multitude of MMORPGs were each serving thousands of simultaneous players and in December 2007 Eve Online achieved a new record with concurrent accounts logged on to the same server. The current record stands at achieved on 2009-02-09.

Despite the genre's focus on multiplayer gaming, AI-controlled characters are still common. NPCs and mobs who give out quests or serve as opponents are typical mostly in MMORPGs. AI-controlled characters are not as common in action-based MMOGs.