Introduction

What is a MUD?

A MUD (Multi-User Dungeon) is a text-based multiplayer world accessed over the internet. Players connect to a MUD server and interact entirely through written text: you read descriptions of rooms, type commands to move and act, and see the results as text output. There are no graphics – everything is conveyed through words, sometimes with color, and sometimes ASCII or ANSI art.

MUDs are the direct ancestors of modern graphical MMORPGs like World of Warcraft and EverQuest. The first MUD was created in 1978 by Roy Trubshaw and Richard Bartle at the University of Essex. Hundreds of MUDs remain active today, many maintained by volunteer communities large and small that have kept them running for decades.

What is Telnet?

Telnet is one of the earliest network protocols still in use today. Developed for ARPANET in 1969 and described in RFC 97, it allowed systems to establish a two-way text-only connection over the internet. Despite its age, Telnet remains widely deployed and used all over the world.

Although later Telnet Protocol standards introduced IAC (“Interpret as Command”) bytes and Option negotiation (WILL/WONT/DO/DONT, RFC 854) to negotiate more advanced features like window size, terminal type, echo and others, a majority of the MUD servers surveyed do not perform any Telnet option negotiation at all. They simply send and receive raw ASCII text, which is fully compliant with the original standard.

See Also: BBSes

Bulletin Board Servers are closely related to MUDs: both primarily use telnet, and are used to play games and chat, BBSs chiefly operate in character-at-a-time mode, while MUDs use line mode. Their preferred clients and servers are sometimes incompatible with each other.

Popular BBS door games, like Legend of the Red Dragon, Usurper, Trade Wars, Barren Realms Elite have similar gameplay, but game design differs due to time limitations to free the telephone line free for other “Callers”.

Playing MUDs today

You may “just telnet” to many MUD servers to try them out. However, for serious playing you will likely want a better client that provides line editing, history control, and command completion not typically ofered by MUD servers. There are also MUD extensions for all kinds of purposes like character stats or even audio.

Two popular open source actively developed clients,

The author of this site has also authored a MUD Client, Telix.

Types of Servers

The term “MUD” is used loosely to describe many kinds of text-based multiplayer servers. They vary widely in purpose:

  • MUD (Multi-User Dungeon)

    The original type. Focused on combat, exploration, quests, and character advancement, usually in a fantasy or science fiction setting. Common codebase families include DikuMUD, LPMud, and ROM.

  • MUSH (Multi-User Shared Hallucination)

    Focused on collaborative storytelling and roleplay rather than combat mechanics. Players can build rooms and objects using an in-game scripting language. Common codebases include PennMUSH, TinyMUSH, and RhostMUSH.

  • MUX (Multi-User eXperience)

    Similar to MUSHes, based on the TinyMUX codebase. Often used for freeform roleplay games set in licensed universes (books, TV shows, etc.).

  • MOO (MUD, Object-Oriented)

    A programmable virtual environment where the world is built from objects with attached code. LambdaMOO is the most well-known example.

  • MUCK (Multi-User Created Kingdom)

    Social and creative environments where players build areas and write programs in MUF (Multi-User Forth). Fuzzball MUCK is the dominant codebase. MUCKs are popular in the furry community.

    Warning

    Adult Content – Some of the most popular servers in this census by player count are not traditional games at all but sophisticated adult chat rooms. All servers of this kind clearly state whether adult content is allowed or strictly forbidden.

Secure Connections (TLS)

A small amount of MUDs support TLS (Transport Layer Security), sometimes also called TELNETS. Servers that support TLS are marked with a lock icon on this site.

Most modern MUD clients support TLS, or stunnel can be used with your system-supplied telnet client. The Python telnetlib3 CLI telnetlib3-client supports TLS using argument, --ssl.

About This Site

This site is a census of Telnet-accessible MUDs.

It provides a fast web interface to

  • Browse MUDs,

  • Preview login banners,

  • and examine their Telnet protocol details

This site is created by the author of Telix, A modern telnet client for BBSs and MUDs. This data is used to supply Telix with a default directory of available servers.

The data is gathered by the telnetlib3-fingerprint CLI to gather the results shown here.

This list of MUDs was primarily sourced from lociterm.com.

It is hosted on Github, and all documentation is auto-generated by code. Suggest a change to mudlist.txt to add or remove or fix an encoding as a pull request. Feel free to suggest any other changes or fixes.

Telnet banners are rendered using IBM VGA 8x16 font and Hack as fallback for other codepoints, especially east-asian (CJK). Banner data is sent to WezTerm for a screenshot, and artificial scanlines and bloom effect are applied.

Better Sites

If you are looking for the most popular MUDs to play with other people, detailed historical and live data, user reviews and descriptions, these other sites are probably a lot more helpful!

Questions

Exercises for the reader!

  • How do MUDs differ from text adventure games and BBSs?

  • Why is ASCII so common? Why are colors optional?

  • What kind of systems do MUDs run on and why is linemode preferred?

  • Why are MUDs popular with the visually impaired?

  • MUD clients offer scripting, what kind of tasks could you automate?

  • What popular games started with MUD codebases? Any famous game developers?

  • Sometimes games require customized clients, why?

  • Why are so few MUDs on the IANA_designated port 23?

  • How do MUD clients differ from BBS clients?