The MUD has a cross-genre setting; the eponymous three kingdoms are Fantasy, Science Fiction, and Chaos, the latter following an anything-goes satirical theme. These settings connect through the MUD's central city of Pinnacle.
A main point of player character differentiation is in the choice of "guild", which is an option resembling a character class, but which, on 3K, can only be chosen once the character has advanced through its first few levels. The exception is the Adventurer guild, which new characters belong to by default. The selection of guilds reflects the cross-genre setting, ranging from fantasy commonplaces such as knights, priests (formerly called clerics), mages, and necromancers to Jedi, cyborgs, Fremen and changelings (formerly called the animal guild).
3K's Web site features ongoing news about the MUD; at one time this news feed was called the 3K New York Times.
- "3-Kingdoms". The Mud Connector. Retrieved 2010-09-14.
- Maloni, Kelly; Baker, Derek; Wice, Nathaniel (1994). Net Games. Random House / Michael Wolff & Company, Inc. p. 90. ISBN 0-679-75592-6. "3 Kingdoms The town of Pinnacle in the center of 3K (as the MUD is commonly called) connects three separate realms: Fantasy, Science Fiction, and Chaos. Fantasy features Dungeons & Dragons; in the Science Fiction realm you can travel by MegaTech train to parts of the United States or through outer space; and in Chaos you'll find anything but the ordinary. On a trip to the grocery store, you'll meet old commercial favorites like Toocan Sam, the Lucky Charm Rabbit, Mr. Clean, and Mr. Whipple. [...] Newbies are quite welcome here — there is even a special newbie land at the south end of the city to build a character's experience. [...] When an adventurer has passed the fifth level, he may choose to join a guild — clerics, witches, animals, necromancers, etc. [...] Server: LPMUD"
- Greenman, Ben; Maloni, Kelly; Cohn, Deborah; Spivey, Donna (1996). Net Games 2. Michael Wolff & Company, Inc. p. 90. ISBN 0-679-77034-8. "[...] head to the Website and read the 3K New York Times — all the news that's fit to cyberprint."
- Olivetti, Justin (2011-04-19). "The Game Archaeologist plays with MUDs: The games". Massively. Archived from the original on 7 May 2011. Retrieved 2011-04-25.
- Hahn, Harley (1996). The Internet Complete Reference (2nd ed.). Osborne McGraw-Hill. p. 727. ISBN 0-07-882138-X. "Three Kingdoms Mud Three Kingdoms has a hierarchy based on a human monarchy, so it achieves variety through guild selection instead of races. This mud is well-loved and full of life as evidenced by not only the traffic, but the high-spirited shouting that seems to be routine. Newbie documents are available at this site via anonymous FTP."
- "The Guilds". 3Kingdoms. Retrieved 2010-11-29.
- "Welcome to the Worlds of Marble!". 3Kingdoms. Retrieved 2010-11-29.