Shared Universe

A shared universe or shared world is a series of fictions written by multiple authors in the same "universe" -- or using shared elements such as particular characterization, plot assumptions, etc. It can be argued that this concept is really as old as Arthurian legend or even mythology.
== In professional fiction ==
Prominent examples of professionally-published shared universes include the Wild Cards series edited by George R. R. Martin and Melinda M. Snodgrass, the 1632 series created by Eric Flint, the Thieves' World series created by Robert Asprin, the Liavek anthologies edited by Emma Bull and Will Shetterly, and the Merovingen Nights books set in C. J. Cherryh's Alliance-Union universe.
== In original online fiction ==
The SCP Foundation is the best-known example of this happening in an online context outside of fanfiction.
== In fanfic == 
Shared universes generally start off as a single story that inspires other fans to use the elements that set that original story apart from canon. Sometimes these shared universes are open for anyone to play in, and sometimes it's just a handful of fans, creating a universe together. 
Sometimes fans utilize a shared universe without permission. See Unauthorized Sequels.
Shared universes started very early in media fandom: the Kraith stories are a set of inter-connected works of Star Trek fan fiction. The earliest were written by Jacqueline Lichtenberg (also creator of the Sime-Gen Universe) beginning in 1969, in the T Negative fanzine, and continued through the first few years after the cancellation of the original TV series. As such, Kraith represents some of the earliest Star Trek fan fiction. By the time interest in Kraith had waned, over 50 writers had written stories in the universe.
In some fandoms, the shared universe can become as popular as the canonical universe, such as The Magnificent Seven fandom's widespread ATF universe, where the seven main characters are taken out of the Old West of canon and pulled forward in time to become modern-day ATF (U.S. Bureau of Alcohol, Tobacco, and Firearms) agents.
In other fandoms, shared universes occupy a niche, such as the Pegasus-B universe in Stargate Atlantis fandom, or the Less Than Legendary Journeys universe in Hercules: The Legendary Journeys fandom. In Pros fandom, an early elf story called The Hunting, by Jane of Australia, grew into a huge multivolume creation that nevertheless was only a small part of the larger Professionals fandom.
Some shared universes are multi-fandom, such as the stories set in Poisontaster's What We Keep universe or Helen's Take Clothes Off As Directed universe, which itself is a riff on Xanthe's Coming Home universe, which is a shared universe of its own. 
Friendfiction is the term used by Original Slash fans for a similar concept.
==Some Examples of Fan Authors' Invites==
From the editor of the 1970's Star Trek zine, Echoes of the Empire: "In most ways, the universe is 'wide open.' So long as an action is effective and does not disrupt the Empire it is fine. It is strictly a 'whatever the traffic will bear' situation'."
From Lady Ra in 2010: "I know I have a tendency to create universes and then take FOREVER to get back to them. So here is an invitation to play in my universes. If you have a yen to create a timestamp for one of my sandboxes, just drop me a quick e-mail and let me know what your idea is. The rules are simple: keep my pairings, don't kill anyone off, and keep things happy! LOL. You know how to get a hold of me... I would love to read whatever you're thinking, and then we can link it to your live-journal, or wherever you want to post it." Visions of Pretty People Doing Naughty (Loving) Things* 
==Some Examples of Fan Author's Invites, But with Many Stipulations==
Some fanfic writers gave their official go-ahead for other fans to write in their universe or use their characters, but imposed many rules.
After she became too overcommitted to do so herself, Jacqueline Lichtenberg allowed others to write in Kraith. The rules and hoops for doing so, however, were staggering. The Kraith Round Robin was the platform. The round robin was intended to maintain the quality of writing and to monitor the continuity of the series. The round robin consisted of fans, mostly Kraith creators in their own right, who have touched upon some aspect of the story in question, or who have simply proven themselves to be capable writers and editors. The early round robins were small, but sometimes a story would go through a cycle of fourteen people, a process that could take many, many months, particularly if the story took on a radical or new concept. This meant the work would get tied down in letter arguments. There were many stories that were never finished due to the amount of time it took for approval. Sometimes the author was asked to make so many changes that she or he simply gave up on the story. The members of the round robin commented on everything from Kraith values and concepts, to plot line and story development, to paragraph organization and grammar. If a similar point of criticism occurred repeatedly in the letters, the story had to be rewritten and sent back to the robin a second time. Any changes in the final draft could only be made by Carol Lynn and Debbie Goldstein (the editors of Kraith Collected) and by Jacqueline Lichtenberg herself.
Another example of a sort of shared universe was with Marion Zimmer Bradley who said that she didn't so much create Darkover as she discovered it, and she encouraged fan fiction writers to write in, what she called, her "back yard." Marion, however, had ultimate control over what got written and where it was published, and was known for being very strict about other authors adhering to certain "realities" in her Darkover universe.
Ruth Kurz was the creator of the Harry & Johnny fandom using the characters Harry Callahan from Dirty Harry and Magnum Force and John Davis from Magnum Force. Ruth recruited many other authors to help write fiction in this very tightly-controlled universe. The lives of Harry and Johnny were thought out in every detail, and aside from a few planned instances, there was no overlap or contradiction in the fiction.
Jean Lorrah requested that fans not create further works in her Epilogue, but said fans are "heartily invited to write" in the universes of The Night of the Twin Moons and Full Moon Rising, though with some hoops to jump through: 
==Some Examples of Fan Author Bans==
Not all fanfic writers were willing to share, even going so far as to threaten other fans with "copyright infringement." 
===Nu Ormenel (1978)===
In 1978, Fern Marder and Carol Walske wrote a personal statement complaining about copyright infringement on the characters/universe they had created: 
Guinn Berger responded: 
Jeff Johnston commented on the idea of shared universes and copyright: 
Fern Marder, co-creator of Nu Ormenel, commented on copyright: 
===Sahaj Universe (1978)===
In 1978, Leslye Lilker addressed the unauthorized use by another fan of a word that Lilker had created: 
===Epilogue (1989)===
In 1989, Jean Lorrah explained why she didn't want other fans to write in the Epilogue universe: 
== Potential Controversy ==
Sometimes writers using shared universes can result in problems or even wank, because there are different assumptions and expectations about how much an author can control a fanfic universe. Not every fan writer enjoys sharing their universes or having remixes made of their work. Some fans feel that any fan story is fair game to be used; others feel it should require specific permission until a shared universe is a certain (indeterminate) size, or has been declared open by the original author. An example for a controversy about different interpretations of a shared universe is the Clan Mitchell wank 2010.WebCite for Clan Mitchell on Journalfen.
In 1989, one fan, Winston Howlett, explained: 
Some fans feel a sequel shouldn't criticize the original, seeing it as other fans "fixing" or rewriting their work, while others think that it is hypocritical for fans to have more rights in their universes than they give the original copyright holders or creators of canon. Problems can arise when someone writing in a specific fan genre (slash, gen, het) finds their universe expanded to include a genre they may not approve of. Similar issues come up with the idea of fannish remixes. 
There's also a fairly subtle differences between writing in someone else's universe, responsefics, and unauthorized sequels.
==List of Named Shared Universes==
*Alex Rider
**The Devil and the Deep Blue Sea
* Dracula
** Blood of My Blood
* Forgotten Realms
* Good Omens
**Slow Show Metaverse
* Gravity Falls
**Transcendence AU
**Reverse Falls
**Mystery Kids
**Monster Falls
**many more (see link)
* Harry & Johnny
*Hercules
**Less Than Legendary Journeys
*Homestuck
**Ke$hastuck
**Petstuck
**Replay Value AU
**Stabdads
**Many more, see Homestuck#Alternate Universe
*House, M.D.
**Contractverse
*The Magnificent Seven
**ATF Universe
**Little Britches
** Old West
*Mary Renault
**ITOWverse
*Multifandom
**Subreality Café
**directedverse
*RPF
**Keptverse
**The 28th Amendment
*SCP Foundation
**Various "canons" or groups of stories that take place in one or more universes but usually within the same realm of existence as a whole
* Sailor Moon
** Sailor Moon Expanded
* Space:1999
** Alphan Biographies
*Star Trek
**Alternate Universe 4
**Kraith
**NTM-universe
**TrekSmut University
*Star Trek: Deep Space Nine
**Deep Dish Nine 
*Star Wars: The Phantom Menace
**Anne Higgins' 'Bonding Universe'
**The Sith Academy
**The JAOA Series
**Riding the Wheel of If
*Stargate (SGA/SG-1 crossovers)
**Pegasus-B
**Langford University
**Fireman!verse
**Denver Legal
**Spygate
**Shermer High
**SG-15
**The House That Jack Built (LJ comm), (collection on AO3) fusion universe (Stargate characters, TBBT setting) with The Big Bang Theory
*Stargate Atlantis
**John!Farr 'verse
**Jaffa For Hire
**Wild West Atlantis
**GPFG Studios
*Stargate SG-1
**Clan Mitchell
*Torchwood
**Askverse
*Total Drama
**Island of the Slaughtered
*Transformers
**MirrorVerse
**Transformers: Alliance
*Undertale
**Underfell
**many more (see link)
*X-Men
**Shadowlands
== References ==
Category:Fiction Writing
*Shared Universe