[[quoteright:300:[[VideoGame/EpicMickey http://static.tvtropes.org/pmwiki/pub/images/nicejobmickey_3129.jpg]]]]
[[caption-width-right:300:[[SarcasmMode Congratulations]], you just created an EldritchAbomination. [[FromBadToWorse Now just wait until you try to fix your mistake.]]]]
->"''How kind of you to open that lock for me. Every time I wonder if it was wise to let you live, you do something like this and show me you're worth keeping around.''"
-->-- [[CardCarryingVillain Thot Trel]], ''VideoGame/StarTrekOnline''

The hero has accomplished their goal; they've killed the BigBad, or defeated them forever, or at least scored a major blow against the antagonist. They've done what they set out to do...

...but [[YourPrincessIsInAnotherCastle not so fast]]! It turns out that by the very act of success, they've unwittingly [[FromBadToWorse made things worse]]. Maybe the now-dead antagonist was actually holding back an [[SealedEvilInACan even greater evil]]. Maybe the villain, having been defeated or damaged, is now [[OneWingedAngel transformed into a new, ultimate, unstoppable, invincible, angry form]], generally [[TorturedMonster against the villain's will]] (or against their expectations, anyway). Maybe the villain, despite their villainy, was serving some other greater good -- keeping the world/universe/nature/whatever politically or literally {{balance|BetweenGoodAndEvil}}d -- and their demise throws things into chaos. Maybe that princess you saved is a cold-hearted tyrant at the head of an oppressive regime. Perhaps taking down the villain has resulted in an EvilPowerVacuum, and now even worse guys are fighting to fill the void that the previous villain left, without a single regard for who else gets hurt. Or perhaps the only means of foiling the villain involves [[GodzillaThreshold questionably massive "collateral damage"]]. For whatever reason, the hero's victory over death and destruction directly or indirectly leads to an even greater wave of death and destruction, or at least an even greater threat of such. Oh dear.

Maybe the villain themselves [[VillainHasAPoint will warn the hero about the possible consequences]], as a last-ditch attempt to save their own skin, or as a bitter "parting shot" to ruin the hero's victory ("You fools... do you even know what you've done?"). Villains being villains, this may just be a bluff. Or maybe the villain will just lament over how the hero defeated them despite all their efforts - it wasn't some sort of {{plan}} of ''theirs'' for the hero to "win" and thus make things worse (if it was, that'd be MyDeathIsJustTheBeginning). Then again, PoorCommunicationKills often comes into play as the villain will usually be uselessly vague and give no concrete reason for why foiling him would be bad. On the other other hand, a clear warning might be taken as CassandraTruth anyway. You can't win.

If the mission was a rescue, it was an UnwantedRescue, and the former captive may bitterly inform them of the true facts.

In most cases, of course, the hero's new mission is to stop the new danger they've unleashed, preferably in a way that doesn't spawn ever greater menaces. Darker plotlines may [[DownerEnding end the story right there]] instead, and it's always possible the villain's demise inadvertently resulted in the [[EarthShatteringKaboom irreversible destruction]] or [[TheEndOfTheWorldAsWeKnowIt horrifying mutation]] of the world. If used excessively, this trope often leaves an audience with a sense that [[NeverBeAHero the hero shouldn't have tried to change things for the better and indeed shouldn't have even left home]], which can be a FamilyUnfriendlyAesop, but also a more literal moral about getting seriously involved in things without learning much about them.

This trope can be annoying in video games as often-times StupidityIsTheOnlyOption, particularly in the case of a MacGuffinDeliveryService... It is not particularly fair to try to make the player feel guilty about a course of action they had no control over, and indeed, might've gotten a "Game Over" if they attempted to ''not'' fulfill the objectives in question.

The term "PyrrhicVictory" has the same connotation and originated from the Pyrrhic War fought by King Pyrrhus in 279 BC, which makes "Nice Job Breaking It, Hero" OlderThanFeudalism. The tropes overlap, but Pyrrhic Victory is when someone succeeds at their goal with a very high price, while Nice Job Breaking It, Hero includes actions that might not be necessary or even intentional. In addition, this trope sometimes results in no victory at all, not even a Pyrrhic one.

Sometimes a badly thought-out plot for the sake of action has exactly the same effect when FridgeLogic catches its tail. That's one of the reasons why a good GameMaster habit is writing the plot starting from the "what happens if {{Player Character}}s aren't here at all or do nothing" point.

This trope is a common problem with the SmallStepsHero. Compare CreateYourOwnVillain, WhatTheHellHero, UnwittingPawn, MustMakeAmends, YouAlreadyChangedThePast, TwoRightsMakeAWrong and NiceJobFixingItVillain (but note that villains are also subject to ''this'' trope -- they can do something careless that screws them over or helps out a ''worse'' villain). Compare WeWantOurJerkBack when the hero/villain makes the villain/hero powerless, only to have it backfire and give them a worse villain/hero/[[ArsonMurderAndJaywalking fate]] than expected, resulting in them wanting things to go back the way they were. BetterTheDevilYouKnow is a similar situation, where the utter defeat of one villain can lead to a completely different and ''greater'' evil taking over. This trope may lead to a RedemptionQuest in an attempt to make up for the mistake. Has very little to do with NiceJobBreakingItHerod (in fact, that one usually leads to the biggest cases of [[NiceJobFixingItVillain the complete opposite Trope]].)

HitlersTimeTravelExemptionAct, in certain cases, is a SubTrope of this. See also HadToComeToPrisonToBeACrook, which is this as applied to a legal system. (Or at least a well-intentioned one.) May overlap with SelfFulfillingProphecy. NoEndorHolocaust is what happens when this is ineptly averted. And if the hero dies following the reveal and is unable to stop the new menace, you've just read a ShootTheShaggyDog story. Despite obvious parallels, most LoadBearingBoss in video games do not fall under this category. When this happens with fandoms, it's WhyFandomCantHaveNiceThings. PacifismBackfire is "Nice Job Sparing Him, Hero".

[[Administrivia/NoRealLifeExamplesPlease No real-life examples are allowed]], and for that, [[SelfDemonstratingArticle you have no one to blame but yourselves]].

'''Spoilers ahead''', of course.

* NiceJobBreakingItHero/AnimeAndManga
** NiceJobBreakingItHero/{{Dragonball}}
* NiceJobBreakingItHero/ComicBooks
* NiceJobBreakingItHero/FanFic
* {{NiceJobBreakingItHero/Film}}
** NiceJobBreakingItHero/MarvelCinematicUniverse
* {{NiceJobBreakingItHero/Literature}}
* NiceJobBreakingItHero/LiveActionTV
* {{NiceJobBreakingItHero/Music}}
* {{NiceJobBreakingItHero/Mythology}}
* NiceJobBreakingItHero/NewMedia
* NiceJobBreakingItHero/{{Other}}
* NiceJobBreakingItHero/ProfessionalWrestling
* {{NiceJobBreakingItHero/Radio}}
* NiceJobBreakingItHero/TabletopRPG
* {{NiceJobBreakingItHero/Theater}}
* NiceJobBreakingItHero/VideoGames
* NiceJobBreakingItHero/WebComics
* NiceJobBreakingItHero/WesternAnimation