[[YuGiOh http://tvtropes.org/pmwiki/pub/images/bakura.jpg]]
[[caption-width:300:There's a reason you don't flirt with the DungeonmastersGirlfriend.]]

-->''If you walk into a room and the floor, walls, and ceiling are all trying to eat you, someone is trying to send you a serious message. Of course it's a serious message told via a killer ceiling, floor, and wall, so really you shouldn't take it to heart.''
-->--[[http://www.headinjurytheater.com/article73.htm Head Injury Theater]] on Lurker Above, Trapper, and Stunjelly, three actual monsters from DungeonsAndDragons.

Opposite to the MontyHaul GameMaster who heaps rewards by the truckful upon his players, the KillerGameMaster has set himself up as a hostile entity playing ''against'' them. To this guy, it hasn't been a good day until the players have been forced to roll up several new characters in a single session. In short, this GameMaster subscribes to the [[http://web.archive.org/web/20080212091754/http://atrocities.primaryerror.net/rpgcliches.html Amber Law]] of gaming; the game session is a zero-sum battle of wits between players and DM, and the DM holds all the cards.

Any world in his hands will inevitably turn into a CrapsackWorld where [[EverythingTryingToKillYou every innocent-looking item]] will turn out to be a DeathTrap which kills the player without so much as a saving throw, every magic item they pick up [[PoisonMushroom will be cursed]], and their every deed will lead to [[FailureIsTheOnlyOption miserable failure]] or end up [[XanatosSucker helping the forces of Darkness (or Light, if your band of adventurers is a bunch of evil doers)]]. They won't be crushing orcs or goblins at Level 1, they'll be getting stomped by ancient red dragons and tarrasques. And frequently, they'll have to make Dexterity checks to avoid ''randomly tripping and falling down''.

If there are Paladins or other characters who depend on a certain alignment, this may also extend to making Paladins fall for such small things that it effectively becomes impossible to actually stay a Paladin for very long. An example of this would be loss of Paladinhood for even the smallest non-combat interaction with an evil character, whose alignment is only revealed after you lose Paladin abilities, as the Paladin code forbids association with characters that you know are evil. Another common 'Killer DM' response to Paladins is to place them in a situation where the paladin [[SadisticChoice must commit an evil act or die/cause the end of the world]]. You can tell if this is the work of a 'killer' if the GameMaster actively torpedoes any attempt to TakeAThirdOption.

The simplest and most brazen of these will simply [[RocksFallEveryoneDies collapse the dungeon on the players]] the moment they enter it. The more subtle have a habit of making life for the average PlayerCharacter a living hell where he will [[YouSuck perpetually suck]]. Going OffTheRails is your only hope, and even then you should keep an eye out for [[RocksFallEveryoneDies falling rocks]]. If the players are competent enough [[{{MinMaxing}} minmaxers]] (or if the group sports a bona-fide {{Munchkin}}), this kind of DM may be necessary just to give them a challenge. Conversely, of course, these kinds of game masters can actually inspire MinMaxing in their players, as they feel they need to to survive.

Some of the oldest ''DungeonsAndDragons'' modules seemed to encourage this sort of [[TrialAndErrorGameplay trial-and-error]], NintendoHard gameplay, such as the infamous ''TombOfHorrors''. Gary Gygax, one of the two creators of D&D, has often been accused of viewing the game as a competition between players and DM, when in actuality, he counseled ''against'' the KillerGameMaster approach in the various D&D manuals. Sometimes, entire ''game settings'' lend themselves to games where a TotalPartyKill is not a question of ''if'', but ''when''.
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!!Examples:

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[[folder: Anime and Manga ]]

* The above scene from the first series of ''{{Yu-Gi-Oh}}!'' is this trope taken to its ultimate extreme: the DM (Bakura, or at least [[SplitPersonality his dark side]]) is not just intending for the players to lose, he's actually outright cheating and even goes as far as to ''invoke evil magic'' against them. Getting a natural 1 or cheating on ''their'' side traps all of the players in their figurines - and by the rules of the game, if their characters run out of HP or the figurines break, they're dead. The trouble for Bakura starts when his good side (a much fairer DM) starts screwing with him...

[[/folder]]

[[folder: Literature ]]

* At the beginning of the third book in PeterDavid's ''SirAproposOfNothing'' series, Apropos plays a roleplaying game (though not called that, since it's already in a fantastic medieval setting) with a ''literal'' killer game master named...[[HurricaneOfPuns Ronnell McDonnell]], of the Clan [=McDonnel=]. (Apropos eventually bests him...and blows a hole in the ship they were all travelling in at the time.)
* In Sharyn [=McCrumb=]'s ''Bimbos of the Death Sun'', Jay Omega plays KillerGameMaster in order to try and ferret out the killer of a famous fantasy author: [[spoiler:He kills the hero of the dead author's novels in a crushing and humiliating fashion, causing the obsessive fanboy to tip his hand and confess.]]
** [[spoiler:And by confess, they mean go AxCrazy.]]
* ''This Is Not a Game'' by Walter Jon Williams characterizes each of four friends by their habits when acting as [=DMs=]. The most antisocial one has every NPC betray the players, and often sets them up to betray each other. The main character eventually realizes that [[spoiler:he expects everyone to betray everyone else in real life as well, and hence betrays them first]].

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[[folder: Newspaper Comics ]]

* In one ''FoxTrot'' storyline, Jason convinces Paige to play a game of ''DungeonsAndDragons'' with him as the DM. After a week's worth of strips of Paige creating characters for her party, Jason [[RocksFallEveryoneDies causes the cave to collapse, killing everyone]], on her very first turn. Followed, of course, by:
-->'''Jason:''' Your bodies will remain undiscovered for...*roll roll roll*...82 centuries!
** Jason also creates equally sadistic dungeons for his friend Marcus in several strips. Only Marcus ''actually enjoys it.''
*** Jason and Marcus's D&D games tend to be a bit...extreme. There was an instance of an Elven archer taking out 10,000 orcs with one shot.

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[[folder: Tabletop Games ]]

* ''{{Amber}}''
* Palladium's ''Beyond The Supernatural'' was tough, but not overtly hard if you weren't fighting a CosmicHorror. However, the corebook included a suggested game mode where the characters played normal people, and the GM rolled up a horrific monster which they had to survive against. The idea was to simulate the sort of stuff that goes on in a slasher flick. HilarityEnsues.
* ''CallOfCthulhu'': [[MemeticMutation Cthulhu devours 1d6 investigators per round]]. Lose 1d10/1d100 Sanity.
* ''[[DontRestYourHead Don't Rest Your Head]]'' plays a strange subversion of this trope by which the GM is basically encouraged to try to kill the Protagonists, but the game rules don't allow for quick deaths, but instead slowly wears the Protagonists down until they die, collapse (a FateWorseThanDeath) or turn into a Nightmare (a Fate Even Worse than Collapsing). The result is that Protagonists are often fairly resilient, but, once the game gets going, always a little to close to the edge for comfort.
* ''{{Warhammer}} Fantasy Roleplay'' and its 40K variant ''DarkHeresy'': Rules as written, it is entirely possible for a Wizard or Psyker to cause a TPK by using a single spell or psychic power (in the latter case, even at the very start of the campaign). Combat is incredibly unforgiving as well. Fate Points alleviate this somewhat by almost acting as extra lives but this game's combat system ''wants you to die'' and a devious GM will be happy to accommodate you.
* ''{{Paranoia}}'' ''demands'' this. The sourcebook makes it crystal clear that this isn't one of those nice [=RPGs=] where the players cooperate and the GM tells them a story. In ''Paranoia'', the GM tries to kill the players and the players try to kill each other. Each player is given a six-pack of clones, with more available for purchase, so that character death is a momentary inconvenience. Which it needs to be, since in ''Paranoia'' if you don't die early and often you're doing it wrong. (And, of course, it's PlayedForLaughs.)
* NinjaBurger is similar to Paranoia, in that it's designed to be extremely easy to die. Simply being seen by an NPC could result in an invisible ninja running up and cutting your head off.
** Forget, "An NPC saw you. A ninja cuts your head off." How about "An NPC saw you. You must commit Seppuku." Yes, the game has an actual mechanic for seppuku.
* ''TheWorldOfDarkness'' (particularly ''Werewolf'' and ''Changeling'')
** In the new WorldOfDarkness, Vampire: The Requiem is the only non-comedic game [[{{Whitewings}} this troper]] knows of where it is entirely possible for the player characters to kill each other on first meeting, simply by playing the rules as written.
* ''TombOfHorrors''
* ''Cyberpunk2020''. It's meant to simulate a gritty, dirty, DarkerAndEdgier city of the future. It encourages the GM to not let the PlayerCharacters relax or rest without being just a little paranoid. Even of each other. Even ''Shadowrun'', in a similar genre, didn't quite go that far in the sourcebook.

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[[folder: Real Life ]]

* Personal anecdotes can be found in [[TroperTales/KillerGameMaster Troper Tales]].
* The Role Playing Game Association's ''Living Greyhawk'' campaign was rumored to have a 25% death rate per table as one of its goals. Even if it wasn't true, their published modules reinforced this belief. This troper has played in modules that have thrown a Lernean hydra at APL(average party level) 1 tables and made the required save versus a disease higher the lower the APL.
** This troper, in Living Greyhawk, has faced both Wraiths and Gauth Beholders at APL 1 & APL 3

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[[folder: Video Games ]]

* ''{{Left 4 Dead}}'' has truly random spawns, but early in development it was discovered that they needed a way to make it so that things are fairly balanced. They created the AI Director, who usually does a good job, making sure that you don't get a long string of good or bad rolls (via monitoring numerous variables, to know when to step in). Then you play on Expert, and find he stops caring about the bad rolls...
* ''MissionForceCyberStorm'' is rife with this, since your Bioderms have limited lifespams, you are enticed to send them out on suicide runs with some weapons mean to turn Bioderms to living suicide bombers.
* In FinalFantasyXI, the '''Chains of Promathia''' expansion was originally set up as an exercise in KillerGameMaster tactics. "Hey there level 75 heroes, who is ready for some adventure?! How would you like to go into a dungeon filled with monsters that can see through sneak and invisible and are so strong that you need 18 people get through it? Now, how about we make it so that you are limited to level 30 when you go in there, so you have to buy whole new sets of otherwise weak and useless gear to clog up your deliciously small inventory? And how about we divide the dungeon up into floors, and to progress you have to wade through a crowded sea of deadly monsters find the right portal? And how about instead of just having the portal up, you instead have to kill a monster and make the portal appear, but there will be several of those monsters and only one will open the portal, the rest will only contain despair? Oh, and those portal monsters will shoot smaller monsters at you that will keep appearing after the main monster dies so that the smaller monsters will swarm members of your party causing them to miss the portal, die, and have to homepoint and lose XP? And how about if at the end of that dungeon, you have to cobble together a workable party with the correct jobs from the people who managed to make it to the top and even then there was a chance of horrible death? Oh, and did I mention that since this dungeon was so much fun, that there are two more exactly like it that you have to beat?" And that was only the first three missions. Fortunately the missions were made much, much, '''much''' easier since then, but people who did the missions when they first came out quickly came to the understanding that the "Chains" part of the expansion's name was just symbolic for the high-grade masochism that you needed to progress in the storyline.

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[[folder: Web Comics ]]

* Matt from ''DorkTower'' and B.A. from ''KnightsOfTheDinnerTable'' are infamous for this. Their players' constant OffTheRails rebellions largely emanate from their frustration over having a control-freak Dungeon Master.
** B.A. tries to craft elaborate adventures involving roleplay, diplomacy, and intrigue but the players immediately opt for Hack and Slash at the first opportunity. BA started out as a bit of a control freak, but the killer GM tendencies came later after Brian and Bob had trashed one too many of his adventures.
* [[http://www.penny-arcade.com/comic/2009/3/4/ This]] ''PennyArcade'' strip.
** And [[http://www.penny-arcade.com/comic/2009/6/22/ this one.]]
** And ''[[http://www.penny-arcade.com/comic/2009/10/9/ this]]'' one. [[AuthorAppeal Remind me not to play with these guys...]]
* Parson Gotti from {{Erfworld}} apparently did this to his gaming group at least some of the time. And ended up stuck in one of his own killer scenarios.

[[/folder]]

[[folder: Web Original ]]

* Al Bruno III of RPG.Net fame keeps a [[http://albruno3.com/ Binder of Shame]] in which he gives fictionalized accounts of his time with a [[DysfunctionJunction truly dysfunctional gaming group]]. The RPG.Net rant "A Night at the Inn, A Day At the Racists" features KillerGameMaster "Psycho Dave," who apart from his habit of having the {{PCs}} roll for ''everything'' as mentioned in the Quotes page, considered the ''Arduin Grimoire'' critical hit tables (which are best described as something out of ''{{Hellraiser}}'') to be ''coddling'' the players. Oh, and that "racists" in the title? [[ThoseWackyNazis It's not]] [[ItGotWorse a typo]].
** Although compared to the [[HighOctaneNightmareFuel horrors]] [[{{Squick}} to]] [[BeyondTheImpossible come]], quick death is a mercy.

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[[folder: Western Animation ]]

* Dexter from ''{{Dexters Laboratory}}'' did this in one episode, but Dee Dee took over and was a more [[MontyHaul benevolent]] DM.

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