-> ''"In [[TabletopGame/DungeonsAndDragons D&D]], there is no act more reckless and fraught with danger than that of outsmarting the DM."''
-->-- '''Shamus Young'''

%% One quote is sufficient. Please place additional quotes on the quotes tab.

Most {{Tabletop RPG}}s isolate one player from the rest to fill the role of the Game Master (or [=GM=]), comprising four major "hats" to wear:
* ''Author'': The [=GM=] plans out ([[SchrodingersGun in the loosest sense]]) the plot of the story of which the PlayerCharacters will become heroes (or villains, or rich, or whatever); creating (or adapting, or just choosing) the setting, populating that region with villains and other {{NPC}}s, and assigning them any necessary backgrounds, motivations, plans and resources. Beware, as overdoing this aspect can lead to {{Railroading}}.
* ''Director'': During the game, while each of the other players typically controls the actions of ''one'' of the Player Characters, the GM decides the actions of all the [=NPCs=] as they are needed. The GM may also direct a particular "NPC" that travels with the party (commonly known as a {{GMPC}}), but this may occasionally be open to abuse since the GameMaster having a [[CreatorsPet "pet" NPC]] may compromise his neutrality.
* ''Referee'': In most {{Tabletop RPG}}s, the rules are supplied to resolve conflicting situations (avoiding the "Bang! you're dead!"/"No, you missed!" quandary). The GM is expected to provide any necessary interpretation of those rules in fuzzier situations. The GM may also approve or provide HouseRules in order to cover these corner cases or provide a different gaming experience. See also RuleZero.
* ''Manager'': The least officially prescribed portion of [=GMing=], and thus the part that takes people the most by surprise. The GM is typically the one to organize the game in the first place, find players, schedule sessions, and figure out a place to play, as well as acting as a mediator and having to balance the needs and desires of all participants -- sometimes having to divine the real desires of indecisive or self-deluded players.

Often, the [=GM=] is separated from the other players at the table by a cardboard screen that hides his notes on [=NPCs=] and upcoming events in the story; many games print custom [=GM=] screens, decorated with various tables and charts from the rulebooks, to reduce the amount of book referencing needed during play. Such screens have become less common -- most [=GM=]s and players prefer to use their computer to create their ''own'' screen, if they ever use one at all.

Game Masters will often be practiced actors, and many of the better [=GM=]s are also talented vocal artists and authors -- for some, they're skills that see a ''lot'' of use, and many games have come into legend because of a memorable [=GM=]-controlled NPC.

The Game Master may encourage a variety of game styles (ranging from UsefulNotes/{{dice}}-heavy hack-and-slash to semi-freeform roleplaying) and moods (ranging from the [[KillerGameMaster sadistic and adversarial]] to [[MontyHaul loot raining from the heavens]]).

Not to be confused with General Motors. Unless you're running some sort of automobile centered RPG. Note that the [=GM=]s in MMO Games (RPG or otherwise) are more like ''moderators'' with punitive powers but no ability to change the fundamentals of the game itself. They're the cops, in other words, whereas a Tabletop [=GM=] is the ruling deity of his or her world.

Renaming the Game Master is a popular option to add a dash of custom flavor to a game:
* ''TabletopGame/DungeonsAndDragons'': "Referee" was the original term used in the very first version (published in 1974 by Creator/GaryGygax and Dave Arneson, may they Role-play In Peace), and in ''TabletopGame/{{Traveller}}'' (published in 1977). "Dungeon Master", or "DM", arrived with ''Advanced Dungeons & Dragons'', from which Game Master became the generic term.
* ''TabletopGame/ArsMagica'': "Storyguide"
* ''TabletopGame/ConspiracyX'': "Chronicler", of the classified files archives.
* ''Ghostbusters'' (West End): "Ghostmaster".
* ''TabletopGame/HeroQuest'' and ''TabletopGame/{{Descent}}'' (Creator/FantasyFlightGames): Both board games cast the Dungeon Master as the Heroes' actual antagonist, the former as the BigBad (Zargon or Morcar, depending on where you bought the game), the latter as the Monster of the Week, called the Overlord.
** However, Descent's ''Road to Legend'' supplement has the Overlord act much more like a traditional EvilOverlord, with evil minions and a plot beyond "kill the other players".
* ''TabletopGame/{{Nobilis}}'': "Hollyhock God"; yes, it's a weird game.
* ''TabletopGame/{{Paranoia}}'': "High Programmer"...sort of. The text actually usually calls him the Game Master, but the GM's section is labeled "Ultraviolet" clearance - which is the clearance of High Programmers.
** Lampshaded in the 25th Edition corebook on High Programmers: Unlike all other books, there is no GM section, since the High Programmers are the [=PCs=], here. Instead, the GM notes get sprinkled around, with the [=PCs=] being told to please not metagame, thank you.
* ''Space Opera'' (Fantasy Games Unlimited): "Star Master", or "SM".
* ''TabletopGame/TheWorldOfDarkness'', ''TabletopGame/{{Exalted}}'', and ''TabletopGame/{{Scion}}'' (White Wolf): "Storyteller".
* ''TabletopGame/{{Toon}}'': "Animator"
* ''TabletopGame/{{Spycraft}}'' (originally Alderac Entertainment Group, then Crafty Games): "Game Control" or "GC".
* The "Aedile" in ''TabletopGame/{{FATAL}}''.
* "Host" in ''TabletopGame/{{Ironclaw}}'', ''Jadeclaw'', and other games from Sanguine Productions -- a term that deliberately emphasizes the ''Managerial'' hat in addition to the others. Even if the "Host" isn't inviting the other players into his ''home'', he's inviting them into his ''world''.
* The '70s third-party supplement vendor, JudgesGuild, got its name from the assumption that the DM was the game's "Judge," but it never caught on as a generic term.
** Yet they still insist on calling the DM that even today, in a rather {{Anvilicious}} manner. They really don't ever give up, do they?
** Though Creator/{{TSR}} themselves used it as a term for the GM of their ''TabletopGame/MarvelSuperHeroes'' role-playing game.
** {{Games Workshop}} also got in on the judicial action, with "Judge Master"s laying down the law in the ''Judge Dredd'' role-playing game.
* "Director" in the RPG adaptations of ''Buffy'', ''Angel'', and ''Army Of Darkness''.
* In ''Castles and Crusades'', they use the term "Castle Keeper."
* "Marshal" in ''TabletopGame/{{Deadlands}}''.
* "Leon" in ''Film/MidnightMadness''.
* "[[ExactlyWhatItSaysOnTheTin Zombie Master]]" in ''TabletopGame/AllFleshMustBeEaten''.
* The "Nightmare Weaver" in [[http://1d4chan.org/wiki/Panic Panic]].
* "Zero Meister" in Spaceship Zero.
* The 1980's company "Pacesetter" (currently out of business) always came up with a term that would fit the initials CM. For their horror game ''Chill'', it was "Chill Master", ''Star Ace'' games were run by a "Campaign Master", and ''Timemaster'' had the "Continuum Master".
* "Dispatcher" in the TabletopGame/NinjaBurger RPG (second edition). Though, in this game, the GM takes on a more proactive role in the game and is an actual party member for all intents and purposes.
* ''TabletopGame/SeventhSea'' simply calls it the Game Master... but in the book Los Vagos (detailing a secret society run by a CaptainErsatz version of {{Franchise/Zorro}} in Castille, Spain's FantasyCounterpartCulture), it's called El Maestro de Juego...which is just Spanish for Game Master. (Said book contains a lot of GratuitousSpanish.)
* ''TabletopGame/DragonRaid'' uses the generic-sounding (but not actually very common) "Adventure Master."
* The ''Series/RedDwarf'' Roleplaying Game calls them the "AI", and encourages a bit of acting on their part beyond the norm.
* ''TabletopGame/CallOfCthulhu'' and all related games use "Keeper of Arcane Lore," usually abbreviated to just "Keeper".
* The CRPG themed "Console" and "Super Console" calls him the "CPU".
* "Game Master" in ''TabletopGame/{{Rifts}}'' and other Palladium systems.
* "Gamesmaster" in TabletopGame/{{Warhammer}} Fantasy Roleplay. Also in Warhammer Quest (the optional roleplaying rules).
* "Host" in ''TabletopGame/CastleFalkenstein'', to maintain the 19th century drawing-room atmosphere. Similarly, a PC is a "Dramatic Persona".
* "Overseeer" in Fallout Pen and Paper.
* As ''LARP/ModelUnitedNations'' has been described as {{LARP}}ing in suits, and crisis committees -- in which you have constantly-changing topics of discussion -- require direction, the equivalent position to Game Master is the "Crisis Staff" (a collective GM of 3-5 members, typically) and the players are "Delegates".
* "[=HoLmeister=]" in ''TabletopGame/{{HoL}}''.
* The Producer of ''TabletopGame/PrimeTimeAdventures''.
* "Mythguide" in ''TabletopGame/AriaCanticleOfTheMonomyth''.
* "Raconteur" in ''TabletopGame/HolyLands''.
* Since 200+ people are playing at the ''LARP/OtakonLARP'', there’s a staff of [=GMs=], usually with specialization in certain areas, and two Co-Head [=GMs=]. There is also a special player category called “Specialist”. They are players that have proven experience and knowledge that allows them to be a little more involved in creating complicated plots with other players, utilizing limited "Manager" and "Referee" roles.
* ''TabletopGame/{{Ryuutama}}'' places the [=GM=] as a "Ryuujin" ([[OurDragonsAreDifferent a dragon that gathers the stories of mortals to nourish its eggs]]) who acts as the party's unseen guardian angel. Interestingly, [[ClassAndLevelSystem Ryuujin level up alongside the players, and each colour has abilities related to different kinds of stories]], giving them aspects of a SupportPartyMember.
* ''TabletopGame/StuporPowers'' says the Game Master needs a cool title to go with his (Or her) position, and thus gives them the moniker of The Big Mac Daddy. (Even if they're female.)
* ''TabletopGame/SpiritOfSeventySeven'': The DJ, evoking the old school [[TheSeventies 1970's]] radio DJ's who spun that groovy vinyl.
** Speaking of TheSeventies, Spectrum Games's -- the same company behind "CartoonActionHour", latest game, "RetroStar", which focus on the decade's televisioned science fiction series, calls the Game Master the Showrunner.
* "Game Chief" in ''TabletopGame/PlanetMercenary''
* "Master of Ceremonies", short "MC", in ''TabletopGame/ApocalypseWorld''. The term was specifically chosen by the author to deemphasize the traditional Author hat of the GM in favor of Director and Referee roles (a.k.a. "ceremonies"), as per Website/TheForge philosophy (which maintains that the authorial control must be spread equally across all participants, not concentrated under the GM). Many games TabletopGame/PoweredByTheApocalypse continue to use the term for this reason. ''TabletopGame/MonsterOfTheWeek'', however, homages ''Cthulhu'' and uses "Keeper" (short for "Keeper of Monsters and Mysteries") instead.