Last updated
MUD Logo.png
Developer(s) Roy Trubshaw
Richard Bartle
Platform(s) Platform independent
Genre(s) Fantasy MUD
Mode(s) Multiplayer
A screenshot from MUD1 MUD1 screenshot.gif
A screenshot from MUD1

Multi-User Dungeon, or MUD (referred to as MUD1, to distinguish it from its successor, MUD2 , and the MUD genre in general), is the first MUD and the oldest virtual world in existence.

<i>MUD2</i> 1985 video game

MUD2 is the successor of MUD1, Richard Bartle's pioneering Multi-User Dungeon. Rather than a sequel, it is the result of over 20 years of continuous development, and is still largely based on the game's original code.

A virtual world is a computer-based simulated environment which may be populated by many users who can create a personal avatar, and simultaneously and independently explore the virtual world, participate in its activities and communicate with others. These avatars can be textual, two or three-dimensional graphical representations, or live video avatars with auditory and touch sensations. In general, virtual worlds allow for multiple users but single player computer games, such as Skyrim, can also be considered a type of virtual world.



MUD was created in 1978 by Roy Trubshaw and Richard Bartle at the University of Essex on a DEC PDP-10. [1] [2] Trubshaw named the game Multi-User Dungeon, in tribute to the Dungeon variant of Zork , which Trubshaw had greatly enjoyed playing. [3] [4] Zork in turn was inspired by an older text-adventure game known as Colossal Cave Adventure or ADVENT. [5]

Richard Bartle British writer, video game designer and computer scientist

Richard Allan Bartle FBCS FRSA is a British writer, professor and game researcher in the massively multiplayer online game industry. He co-created MUD1 in 1978, and is the author of the 2003 book Designing Virtual Worlds.

University of Essex university in Essex, England

The University of Essex is a public research university in Essex, England. It was established in 1963, welcomed its first students in 1964 and received its Royal Charter in 1965. Essex's motto, "Thought the harder, heart the keener", is adapted from the Anglo-Saxon poem The Battle of Maldon.

Digital Equipment Corporation (DEC), using the trademark Digital, was a major American company in the computer industry from the 1950s to the 1990s.

MUD1 was written in the domain-specific programming language Multi User Dungeon Definition Language (MUDDL). [6] Its first version was written by Richard Bartle and Roy Trubshaw in BCPL. It was later ported to C++ [7] and used in other MUDs such as MIST . [6]

A domain-specific language (DSL) is a computer language specialized to a particular application domain. This is in contrast to a general-purpose language (GPL), which is broadly applicable across domains. There are a wide variety of DSLs, ranging from widely used languages for common domains, such as HTML for web pages, down to languages used by only one or a few pieces of software, such as MUSH soft code. DSLs can be further subdivided by the kind of language, and include domain-specific markup languages, domain-specific modeling languages, and domain-specific programming languages. Special-purpose computer languages have always existed in the computer age, but the term "domain-specific language" has become more popular due to the rise of domain-specific modeling. Simpler DSLs, particularly ones used by a single application, are sometimes informally called mini-languages.

BCPL is a procedural, imperative, and structured computer programming language. Originally intended for writing compilers for other languages, BCPL is no longer in common use. However, its influence is still felt because a stripped down and syntactically changed version of BCPL, called B, was the language on which the C programming language was based. BCPL introduced several features of modern programming languages, including using curly braces to delimit code blocks.

C++ general purpose high-level programming language

C++ is a general-purpose programming language created by Bjarne Stroustrup as an extension of the C language, or "C with Classes". The language has expanded significantly over time, and modern C++ has object-oriented, generic, and functional features in addition to facilities for low-level memory manipulation. It is almost always implemented as a compiled language, and many vendors provide C++ compilers, including the Free Software Foundation, LLVM, Microsoft, Intel, and IBM, so it is available on many platforms.

In 1980, Roy Trubshaw created MUD version 3 in BCPL (the predecessor of C), to conserve memory and make the program easier to maintain. [8] Richard Bartle, a fellow Essex student, contributed much work on the game database, introducing many of the locations and puzzles that survive to this day. Later that year Roy Trubshaw graduated from Essex University, handing over MUD to Richard Bartle, who continued developing the game. [9] That same year, MUD1 became the first Internet multiplayer online role-playing game as Essex University connected its internal network to the ARPANET. [10]

In 1983, Essex University allowed remote access to its DEC-10 via British Telecom's Packet Switch Stream network between 2 am and 7 am each night. [11] MUD became popular with players around the world, and several magazines wrote articles on this new trend. [12]

In the United Kingdom, Packet Switch Stream (PSS) was an X.25-based packet-switched network, provided by the British Post Office Telecommunications and then British Telecommunications starting in 1980. After a period of pre-operational testing with customers the service was launched as a commercial service on 20 August 1981. The experimental predecessor network (EPSS) formally closed down on 31 July 1981 after all the existing connections had been moved to PSS.

Between 1984 and 1987, MUD was hosted on the DEC-20 of Dundee College of Technology [13] which was one of the few institutions to allow outside access.

Abertay University university

Abertay University, operating name for the University of Abertay Dundee since 2014, is one of two public universities in the city of Dundee, Scotland. In 1872, Sir David Baxter, 1st Baronet of Kilmaron, left a bequest for the establishment of a mechanics' institute in Dundee and the Dundee Institute of Technology was formed in 1888. As early as 1902 it was recognised by the Scottish Education Department as an educational hub, and was one of the first to be designated a central institution, akin to an 'industrial university'. Abertay gained University status in 1994.

In 1984, Compunet, a UK-based network primarily for Commodore 64 users, licensed MUD1 and ran it from late 1984 until 1987, when CompuNet abandoned the DEC-10 platform they were using. [14]

Trubshaw and Bartle worked together at Multi-User Entertainment to create MUD2 the second generation of MUD. [15] In 1985, Richard Bartle created MUD1 version 4, better known as MUD2. It was intended to be run as a service for British Telecom. [16]

In 1987, MUD1 was licensed by CompuServe, who pressured Richard Bartle to close down the instance of MUD1, better known as 'Essex MUD', that was still running at Essex University. This resulted in the deletion of the MUD account in October 1987. This left MIST , a derivative of MUD1 with similar gameplay, 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. [17]

MUD1 ran under the name British Legends until late 1999 and was retired along with other software during CompuServe's Y2K cleanup efforts. [18]

In 2000, Viktor Toth rewrote the BCPL source code for MUD1 to C++ and opened it alongside MUD2 on [19]

In 2014, Stanford University secured permission to redistribute the game's blueprints from the authors of MUD1. [20]


Computer Gaming World in 1993 called British Legends on CompuServe "your typical text-based multi-player role-playing game with an emphasis on magic". [21]

Related Research Articles

PDP-10 36 bit mainframe computer family built 1966-1983

Digital Equipment Corporation's PDP-10, later marketed as the DECsystem-10, was a mainframe computer family manufactured beginning in 1966; it was discontinued in 1983. 1970s models and beyond were marketed under the DECsystem-10 name, especially as the TOPS-10 operating system became widely used.

AberMUD was the first popular open source MUD. It was named after the town Aberystwyth, in which it was written. The first version was written in B by Alan Cox, Richard Acott, Jim Finnis, and Leon Thrane based at University of Wales, Aberystwyth for an old Honeywell mainframe and opened in 1987.

DikuMUD is a multiplayer text-based role-playing game, which is a type of MUD. It was written in 1990 and 1991 by Sebastian Hammer, Tom Madsen, Katja Nyboe, Michael Seifert, and Hans Henrik Stærfeldt at DIKU —the department of computer science at the University of Copenhagen in Copenhagen, Denmark.

Online creation, also referred to as OLC, online coding, online building, and online editing, is a software feature of MUDs that allows users to edit a virtual world from within the game itself. In the absence of online creation, content is created in a text editor or level editor, and the program generally requires a restart in order to implement the changes.

The MUD trees below depict hierarchies of derivation among MUD codebases. Solid lines between boxes indicate code relationships, while dotted lines indicate conceptual relationships. Dotted boxes indicate that the codebase is outside the family depicted.

LPMud, abbreviated LP, is a family of MUD server software. Its first instance, the original LPMud game driver, was developed in 1989 by Lars Pensjö. LPMud was innovative in its separation of the MUD infrastructure into a virtual machine and a development framework written in the LPC programming language.

A persistent world or persistent state world (PSW) is a virtual world which, by the definition by Richard Bartle, "continues to exist and develop internally even when there are no people interacting with it". The first virtual worlds were text-based and often called MUDs, but the term is frequently used in relation to massively multiplayer online role-playing games (MMORPGs) and pervasive games. Examples of persistent worlds that exist in video games include Battle Dawn, EVE Online, and Realms of Trinity.

TinyMUD is the name of a MUD server codebase, and the first MUD running that codebase. The MUD itself has subsequently come to be known as "TinyMUD Classic" or simply "Classic", or occasionally "DaisyMUD". To distance itself from the combat oriented traditional MUDs it was said that the "D" in TinyMUD stood for Multi-User "Domain" or "Dimension", which led to the eventual adoption of the term MU* to refer to TinyMUD and its many derivatives.

Kelton Flinn American video game designer

Kelton Flinn is an American computer game designer who is a major pioneer in online games. He is a co-founder of the seminal online game company Kesmai, which they began in 1982. His best known title is the first graphical multi-player online game offered by a major service, Air Warrior (1987).

A text game or text-based game is an electronic game that uses a text-based user interface, that is, the user interface employs a set of encodable characters such as ASCII instead of bitmap or vector graphics.

Island of Kesmai was an early commercial online game in the MUD genre, innovative in its use of roguelike pseudo-graphics. It is considered a major forerunner of modern MMORPGs.

The history of massively multiplayer online games spans over thirty years and hundreds of massively multiplayer online games (MMOG) titles. The origin and influence on MMO games stems from MUDs, Dungeons & Dragons and earlier social games.

TinyMUCK or, more broadly, a MUCK, is a type of user-extendable online text-based role-playing game, designed for role playing and social interaction. Backronyms like "Multi-User Chat/Created/Computer/Character/Carnal Kingdom" and "Multi-User Construction Kit" are sometimes cited, but are not the actual origin of the term; "muck" is simply a play on the term MUD.

Muddle may refer to:

God or Goddess, in MUDs, often refers to an administrator of a MUD server, most typically the owner. Sometimes multiple individuals with the title of God are present, or the term may even be applied to all administrative and development staff, but it is usual for the term to refer to the most senior administrator. A similar term, mostly used in DikuMUDs, is implementer, or "imp".

<i>Avalon: The Legend Lives</i>

Avalon: The Legend Lives is a text-based online multi-player role-playing game world that was first released on 28 October 1989 at the gaming convention Adventure 89. It has maintained a continuous on-line presence with consistent and intact persona files and player history since the late 1980s, rendering it the longest continuously running on-line role-playing game in history.


  1. Sloane, Sarah (2000) Digital Fictions: Storytelling in a Material World, Ablex Publishing Corporation, ISBN   978-1-56750-482-8, p. 168
  2. Slator, Brian M. et al "From Dungeons to Classrooms: The Evolution of MUDs as Learning Environments", in Jain, Lakhmi C., Tedman, Raymond A. & Tedman, Debra K. (eds.) (2007) Evolution of Teaching and Learning Paradigms in Intelligent Environment, Springer, ISBN   978-3-540-71973-1, p. 121-2
  3. Kevin Kelly, Howard Rheingold (1993). "The Dragon Ate My Homework". Wired . 1 (3). In 1980, Roy Trubshaw, a British fan of the fantasy role-playing board game Dungeons and Dragons, wrote an electronic version of that game during his final undergraduate year at Essex College. The following year, his classmate Richard Bartle took over the game, expanding the number of potential players and their options for action. He called the game MUD (for Multi-User Dungeons), and put it onto the Internet.
  4. Richard Bartle (2003). Designing Virtual Worlds. New Riders. p. 741. ISBN   0-13-101816-7. The "D" in MUD stands for "Dungeon" [...] because the version of ZORK Roy played was a Fortran port called DUNGEN.
  5. Tim Anderson; Stu Galley (1995). "The History of Zork". Archived from the original on 2009-01-16. Zork was too much of a nonsense word, not descriptive of the game, etc., etc., etc. Silly as it sounds, we eventually started calling it Dungeon. (Dave admits to suggesting the new name, but that's only a minor sin.) When Bob the lunatic released his FORTRAN version to the DEC users' group, that was the name he used.
  6. 1 2 Bartle, Richard (1999). "MUDDL". Many MUDDL databases were written by students at Essex University, the most well-known being 'Mist', 'Rock', 'Blud' and 'Uni' [...]
  7. Bartle, Richard (2002). "Incarnations of MUD". Viktor Toth had had a copy of the BCPL source code for MUD1 for some years, and decided that now was the time to do something with it. In a 9-day programming blitz over Christmas, he rewrote the BCPL MUDDL engine in C++ and opened it up alongside MUD2. The ex-CompuServe players gravitated there, where it now runs as a direct continuation of the defunct original BL incarnation.
  8. Richard Bartle (1990). "Early MUD History". The program was also becoming unmanageable, as it was written in assembler. Hence, he rewrote everything in BCPL, starting late 1979 and working up to about Easter 1980. The finished product was the heart of the system which many people came to believe was the "original" MUD. In fact, it was version 3.
  9. Eddy Carroll (1995). "MUD Timeline". Roy graduates from Essex University, and Richard takes full control of the game, fleshing out the database and adding additional commands. A proper persona communication system is introduced, along with the concepts of points and wizards.
  10. Mulligan, Jessica; Patrovsky, Bridgette (2003). Developing Online Games: An Insider's Guide. New Riders. p. 444. ISBN   1-59273-000-0. 1980 [...] Final version of MUD1 completed by Richard Bartle. Essex goes on the ARPANet, resulting in Internet MUDs!
  11. Eddy Carroll (1995). "MUD Timeline". Essex University allows outside users to access its DEC-10 via BT's Packet Switch Stream network (PSS) during the normally idle period from 2am to 8am each night.
  12. Richard Bartle (1995). "MUD Magazine Bibliography".
  13. Richard Bartle (2004). "Designing Virtual Worlds". Furthermore, it only ran on DEC-10, and although copies were sent to other institutions in the U.K., Sweden, and Norway, only two of these allowed outsiders access (Dundee Technical College and Oslo University).
  14. Richard Bartle (1999). "CompuNet MUD". The incarnation of MUD1 on the CompuNet network in the UK, the first commercial MUA in the world.
  15. "MUSE's Personnel",, retrieved 2010-12-18
  16. Richard Bartle (2002). "MUSE background". A new version of the game, which came to be known as MUD2, was written in 1985 to be run as a service for British Telecom.
  17. Michael Lawrie (2003). "Escape from the Dungeon". October of 1987 was chaos. The MUD account was deleted, but the guest account on Essex University remained open. I guess it wasn't causing any trouble so they simply left it. ROCK, UNI and MUD all ran from the MUD account so they had gone but... MIST ran from a student account and it was still playable.
  18. Richard Bartle (2007). "A Brief History". Due in part to a fortuitous coincidence (MUD was written for the same DECSystem-10 computing platform that CompuServe used for its information service) MUD was licensed by CompuServe in the mid-1980s where it ran as a popular game until late 1999. It was eventually retired along with other software during CompuServe's Y2K cleanup efforts.
  19. Richard Bartle (2002). "Incarnations of MUD". Viktor Toth had had a copy of the BCPL source code for MUD1 for some years, and decided that now was the time to do something with it. In a 9-day programming blitz over Christmas, he rewrote the BCPL MUDDL engine in C++ and opened it up alongside MUD2. The ex-CompuServe players gravitated there, where it now runs as a direct continuation of the defunct original BL incarnation.
  20. Simon Sharwood (2014). "Source code for world's first MUD, Essex Uni's MUD1, recovered". The code has landed at Stanford University, which says it has secured permission to redistribute the game's blueprints from the authors Richard Bartle and Roy Trubshaw.
  21. "A Survey of On-Line Games". Computer Gaming World. May 1993. p. 84. Retrieved 7 July 2014.