A MUSH, commonly known as a "'''[[MultiUserSharedHallucination M]]'''[[MultiUserSharedHallucination ulti-]]'''[[MultiUserSharedHallucination U]]'''[[MultiUserSharedHallucination ser]]''' [[SharedMassHallucination S]]'''[[SharedMassHallucination hared ]]'''[[SharedMassHallucination H]]'''[[SharedMassHallucination allucination]]", is a text-based online environment with its roots in InteractiveFiction. However, the title {{MUSH}}, like {{MUCK}}, is a pun on {{MUD}} (MultiUserDungeon), and rather good [[FunWithAcronyms backronyms]] suggested by TheOtherWiki also include '''M'''ulti-'''U'''ser '''S'''hared '''H'''ack, '''H'''abitat or '''H'''olodeck.

Progressing down the text-based online game 'system reliance' scale from {{MUCK}}s, MUSH games are usually perceived as having the least systems support for roleplay. Whereas a {{MUD}} will usually provide players with an entire game's worth of systems to play with, roleplay or otherwise, and [=MUCKs=] offer their players systems comparable to those of Pen&Paper {{RPG}}s, a MUSH will often merely be a series of rooms, and only enough systems to allow players to communicate with one another in various ways, along with the occasional currency system. In other words, MUSH games generally encourage and trust their players to create and manage their own roleplay.
Not to be confused with the video game [[VideoGame Mush]] or [[VideoGame/MushTheDawn the other game]] [[NamesTheSame of the same name.]]

!!Tropes common to [=MUSHes=]:
* AlternativeCharacterInterpretation: Quite often, where non-original/feature characters are concerned.
* Just about everything on the CreatorStandpointIndex applies to a [=MUSH=] at one point or another, whether you're talking about players and characters, or the staff and the [=MUSH=] itself.
* {{Crossover}}: Sometimes happens.
** MassiveMultiplayerCrossover: Often the result.
*** UltimateShowdownOfUltimateDestiny: The logical conclusion.
** MegaCrossover: When people really get creative.
* FanFiction: Essentially, in the case of [=MUSHes=] without their own, original setting or that allow for elements from other settings.
* OriginalCharacter: [=MUSHes=] are usually divided between original settings (often requiring original characters) and settings based on pre-existing franchises (which often allow original characters, too).
* TheWikiRule: In more modern times, this has increasingly become the norm for existing and startup [=MUSHes=].

!!!Notable [=MUSHes=], past and present:
* [[http://www.akashat.com/ Akashat]]: An original setting, adult-roleplay MUSH. Noteworthy due to its firm focus on continuity, in-depth roleplay and complex storylines. Does not allow non-original characters.
* [[http://www.castledimage.net/ Castle D'Image]]: Quite an old MUSH set in an original fantasy setting. Defunct.
* [[http://champions.briancentral.com/ Champions MUSH]]: Uses the {{Champions}} system of developing and playing your own superhero.
* [[http://http://www.cityofhopemush.com/wiki/index.php/Main_Page City of Hope MUSH]]: Largest Old World of Darkness MUSH. Running Revised. Open Chargen. [[http://youtu.be/tIEe5A2MLA8 Check out our trailer]]
* [[http://elendor.net/index.php/Main_Page Elendor]]: The oldest, biggest, and longest-running Tolkien-themed MUSH, founded in 1991, set shortly before ''Literature/TheLordOfTheRings''. Had a huge membership when the movies came out, but has since dwindled.
* [[http://eqdawn.hoofington.com/Main_Page Equestrian Dawn]]: A relatively new MUSH based on the popular ''[[WesternAnimation/MyLittlePonyFriendshipIsMagic My Little Pony: Friendship is Magic]]'' television series. Quite active, although some bugs due to significant amounts of custom code work and ongoing development.
* [[http://www.endlesscitymush.com/doku.php Endless City MUSH]]: A cross-genre superhero MUSH (which permits almost everything), set in The City, a location that exists outside of time and space, that's connected to every universe, and every time ever. It's easy to get in, and easy to leave, the hard part is finding Home again.
* [[http://heroesmush.wikidot.com/ Heroes MUSH]]: Based on the ''{{Series/Heroes}}'' TV series, with a similar approach to game-wide [[StoryArc story arcs]] (Volumes), [[{{Flashback}} flashbacks]] and [[BadFuture potential dystopian futures]]. Defunct.
* [[http://www.mudconnect.com/mud-bin/adv_search.cgi?Mode=MUD&mud=Mega+Man+Mush Mega Man MUSH]]: A rather long-standing MUSH based on the ''VideoGame/MegaMan'' games. Combines elements from almost all of the various series into one coherent setting, albeit by taking quite a few liberties with the canon time line. Has a [[http://www.megamanmush.com/ website and wiki]].
* [[TheMultiverse Multiverse]] [[CrisisCrossover Crisis]] [=MUSH=]: [[http://multiversemush.com/mw/index.php?title=Main_Page Huge crossover MUSH]]. Has all sorts of characters and themes crammed together more or less indiscriminately.
* {{Otherspace}}: One of the longest-running [=MUSHes=] (online since 1998), [[http://www.jointhesaga.com/ OtherSpace]] is self-described as a space opera/science fantasy interactive saga. Notable for having had 17 game-wide story arcs (plus hundreds of more localized ones) and for being willing to completely alter the structure of the game in order to keep the story going. Has a [[http://www.jointhesaga.com/oswiki/ wiki]].
* [[http://www.pokemorph.com/ Pokemorph MUSH]]: A place in the {{Pokemon}} world where Team Rocket experimented on fusing human genes to Pokemon. Most, if not all, of the results live on the island within the game. Notable for being the longest running and one of the largest Pokemon-based MUSH still active.
* [[Franchise/ShinMegamiTensei Persona]] MUSH: This MUSH focuses on fusing the four main Persona games together in a coherent fashion, with occasional shout outs and injokes to other games in the Shin Megami Tensei series. Also has a [[http://www.mysterymeep.net/mw/index.php?title=Main_Page wiki]].
* Shangri La: An intensely pornographic multiverse fetish game and consistent chief contender for the largest MUSH still around, as of 2014. If you're not into extreme internet/BDSM kink culture and/or are under 18, you ''really'' should avoid this one. They don't mess around here. Due to the aforementioned pornographic content, we're not linking to it here. If you want to play it, Google it yourself.
* [[VideoGame/SuperRobotWars Super Robot Taisen]] MUSH: Based on the ''VideoGame/SuperRobotWarsOriginalGeneration'' games with basically every mecha series they could think of integrated, from the typical fare of [[MobileSuitGundam Gundam]] and {{Macross}} to TabletopGame/{{BattleTech}} and {{Xabungle}}. Has a [[http://wiki.srtmush.com/ wiki]].
* [[WesternAnimation/CaptainNTheGameMaster Videoland]] MUSH: Defunct. In its prime was a (slightly) more-serious take on its [[WesternAnimation/CaptainNTheGameMaster source material]], expanding the cast to eight (and eventually ten) Gamemasters instead of just one.
* [[http://transformers2005.wikia.com/wiki/Main_Page Transformers 2005 MUSH]]: Longest-running and most successful Transformers-based game. Based on the original WesternAnimation/TransformersTheMovie. Running since Apr. 8, 1995.
* [[http://tfumux.wikia.com/wiki/Transformers_Universe_MUX_Wiki Transformers Universe]]: A slightly different Transformers game, based on Season Two of WesternAnimation/TheTransformers as well as GIJoe. Running since May of 1997.