In computer gaming, a MUD (Multi-User Dungeon, Domain or Dimension) is a multi-player computer game that combines elements of role-playing games, hack and slash style computer games and social chat rooms. Typical MUDs are text-driven, where players read descriptions of rooms, objects, events, other characters, and computer-controlled creatures or non-player characters (NPCs) in a virtual world. Players interact with each other and the world by typing commands that resemble a natural language. It has been argued that modern game-like MMORPGs, such as World of Warcraft, and social virtual worlds such as Second Life can have their origins traced back to the original MUDs.
Traditional MUDs implement a fantasy world populated by fictional races and monsters, with players being able to choose from a number of classes in order to gain specific skills or powers. The object of this sort of game is to slay monsters, explore a fantasy world, complete quests, go on adventures, create a story by roleplaying, and advance the created character. Many MUDs were fashioned around the dice rolling rules of the Dungeons & Dragons series of games.
Such fantasy settings for MUDs are common, while many others are set in a science fiction–based universe or themed on popular books, movies, animations, history, and so on. Not all MUDs are games; some, more typically those referred to as MOOs, are used in distance education or for virtual conferences. MUDs have attracted the interest of academic scholars from many fields, including communications, sociology, law, and synthetic economies.
Most MUDs are run as hobbies and are free to players; some may accept donations or allow players to "purchase" in-game items, while others charge a monthly subscription fee.
Adventure, created in 1975 by Will Crowther on a DEC PDP-10 computer, was the first widely used adventure game. The game was significantly expanded in 1976 by Don Woods. Adventure contained many D&D features and references, including a computer controlled dungeon master.
Inspired by Adventure, a group of students at MIT, wrote a game called Zork in the summer of 1977 for the PDP-10 minicomputer which became quite popular on the ARPANET. Zork was ported under the name Dungeon to FORTRAN by a programmer working at DEC in 1978.
In 1978 Roy Trubshaw, a student at Essex University in the UK, started working on a multi-user adventure game in the MACRO-10 assembly language for a DEC PDP-10. He named the game MUD (Multi-User Dungeon), in tribute to the Dungeon variant of Zork, which Trubshaw had greatly enjoyed playing. Trubshaw converted MUD to BCPL (the predecessor of C), before handing over development to Richard Bartle, a fellow student at Essex University, in 1980.
MUD, also known as Essex MUD and MUD1 in later years, ran on the Essex University network until late 1987. It was reportedly closed down when Richard Bartle licenced MUD1 to CompuServe, and was getting pressure from them to close Essex MUD. This left MIST, a derivative of MUD, as the only remaining MUD running on the Essex University network, becoming one of the first of its kind to attain broad popularity. MIST ran until the machine that hosted it, a PDP-10, was superseded in early 1991.
The popularity of MUDs of the Essex University tradition escalated in the USA during the 1980s when affordable personal computers with 300 to 2400 bit/s modems enabled role-players to log into multi-line Bulletin Board Systems and online service providers such as CompuServe. During this time it was sometimes said that MUD stands for "Multi Undergraduate Destroyer" due to their popularity among college students and the amount of time devoted to them.
Another early PLATO game was Avatar, begun around 1977 and opened in 1979, written by Bruce Maggs, Andrew Shapira, and Dave Sides, all high school students using the PLATO system at the University of Illinois. This 2.5-D game was running on 512x512 plasma panels of the PLATO system, and groups of up to 15 players could enter the dungeon simultaneously and fight monsters as a team.
In 1978, Alan E. Klietz wrote a game called Milieu using Multi-Pascal on a CDC Cyber 6600 series mainframe which was operated by the Minnesota Educational Computing Consortium. High school students from around the state were given access to the machine for educational purposes. Klietz ported Milieu to an IBM XT in 1983, naming the new port Scepter of Goth. Scepter supported 10 to 16 simultaneous users, typically connecting in by modem. It was one of the first commercial MUDs; franchises were sold to a number of locations. Scepter (and an unfinished advanced MUD by Klietz called ScreenPlay) was first owned and run by GamBit (of Minneapolis, Minnesota), founded by Bob Alberti. GamBit's assets, including Scepter and ScreenPlay, were later sold to InterPlay (of Fairfax, Virginia). InterPlay eventually went bankrupt, making Scepter no longer available. In 1984, Mark Peterson wrote The Realm of Angmar, beginning as a clone of Scepter of Goth. In 1994, Mark Peterson rewrote The Realm of Angmar, adapting it to MS-DOS (the basis for many dial-in BBS systems), and renamed it Swords of Chaos. For a few years this was a very popular form of MUD, hosted on a number of BBS systems, until widespread Internet access eliminated most BBSes
In 1984, Mark Jacobs created and deployed a commercial gaming site, Gamers World. The site featured two games coded and designed by Jacobs, a MUD called Aradath (which was later renamed, upgraded and ported to GEnie as Dragon's Gate) and a 4X science-fiction game called Galaxy, which was also ported to GEnie. At its peak, the site had about 100 monthly subscribers to both Aradath and Galaxy. GEnie was shut down in the late 1980s, although Dragon's Gate was later brought to America Online before it was finally released on its own. Dragon's Gate was officially closed on February 10th, 2007 until further notice.
Another early commercial multi-player game was Islands of Kesmai designed by Kelton Flinn and John Taylor. This roguelike game featuring a Dungeons and Dragons-like turn-based play became available to consumers in 1984 for $12.00 per hour via the CompuServe online service.
These text-adventure games (both single and multi-player) drew inspiration from the paper-and-pencil based role-playing games (RPGs) that were approaching their peak popularity at this time, especially with the release of Advanced Dungeons & Dragons (AD&D) in 1977.
This strong bond between RPGs and MUDs continued through the years with the release of dozens of AD&D modules and related books and stories (e.g., Forgotten Realms and Dragonlance). Influences also came from the gamebooks such as Fighting Fantasy, Choose Your Own Adventure, and Lone Wolf.
Other MUDs that appeared around 1985 included Mirrorworld, run by Pip Cordrey and developed and written by Tim Rogers, Lorenzo Wood and Nathaniel Billington. Mirrorworld was the first MUD to feature rolling resets. SHADES by Neil Newell was a commercial MUD accessible in the UK via British Telecom's Prestel and Micronet networks. A scandal on SHADES led to the closure of Micronet, as described in Indra Sinha's net-memoir, The Cybergypsies.
1989 saw the development of Avalon, which adopted an object-oriented approach using the British Acorn Archimedes computer technology. The three largest commercial MUDs in the early 90s were Avalon, Shades and the Terris/Cosrin Engine.
In the mid 90s AOL US ran several highly successful games, including Dragons Gate and Darkness Falls (by Mythic Entertainment, which later launched Dark Age of Camelot), Federation (game) (a space trading game) and Gemstone III (Simutronics, which later launched Hero's Journey).
The first popular MUD codebase was AberMUD, written in 1987 by Alan Cox, named after the University of Wales, Aberystwyth. Alan Cox had played the original University of Essex MUD, and the gameplay was heavily influenced by it. AberMUD was initially written in B for a Honeywell L66 mainframe under GCOS3/TSS and later ported to C in late 1988, which enabled it to rapidly spread to many Unix platforms when it was released in 1989. AberMUD's popularity resulted in several inspired works, the most notable of these were TinyMUD, LPMUD, and DikuMUD.
Monster was a multi-user adventure game created by Richard Skrenta for the VAX and written in VMS Pascal. It was publicly released in November 1988. Monster was disk-based and modifications to the game were immediate. Monster pioneered the approach of allowing players to build the game world, setting new puzzles or creating dungeons for other players to explore. Monster, having about 60.000 lines of code, had a lot of features which appeared to be designed to allow Colossal Cave Adventure to work in it. Though there never were many network-accessible Monster servers, it inspired James Aspnes to create a stripped down version of Monster which he called TinyMUD.
TinyMUD written in C and released in late 1989 spawned a number of descendants, including TinyMUCK and TinyMUSH. TinyMUCK versions 2 contained a full programming language named MUF (Multi-User Forth), while MUSH greatly expanded the command interface. Some use the term MU* to refer to TinyMUD, MUCK, MUSH, MUSE, MUX, and their kin. UberMUD, UnterMUD, and MOO were inspired by TinyMUD but are not direct descendants.
In 1991, the release of DikuMUD, which was inspired by AberMUD, led to a virtual explosion of hack-n-slash MUDs based upon its code. DikuMUD inspired several derivative codebases too, including CircleMUD, Merc, SillyMUD, ROM, SMAUG, and GodWars.
Online graphics-based games (MMORPGs), such as EverQuest, Lineage II, and World of Warcraft, as well as graphics-based virtual worlds like Second Life, are arguably analogous to MUDs, and are sometimes referred to as "graphical MUDs" (see next section) or "next-generation MUDs".
Similarities include the basic goals and objectives of the games and the society of the environments. One difference is that the majority of MMORPGs and social avatar worlds are commercial ventures. The Business of Social Avatar Virtual Worlds
After the increase in computing power and Internet connectivity during the late nineties, graphical MUDs became better known as MMORPGs, Massively Multiplayer Online Role-Playing Games.
A player versus player, or player killing, MUD is one which encourages player versus player combat. Some MUDs have registered player killing, meaning a player must register as a player killer and can only fight other registered player killers.