History Main / EvilOnlyHasToWinOnce

It just doesn't seem fair. Why is it that beating the BigBad doesn't bring about a thousand years of perpetual (hopefully not literal) light? There's two potential [[JustifiedTrope justifications for this]]: Good, ''[[LightIsGood true]]'' Good, won't [[UtopiaJustifiesTheMeans stoop]] to [[TheEvilsOfFreeWill the levels]] necessary to create a permanent SugarBowl, whereas Evil won't have a problem with completely wrecking the world. The other reason is that the Good Guys are usually the only ones concerned with maintaining the BalanceBetweenGoodAndEvil. Metatextually, the Author also probably wants a world where his ChronicHeroSyndrome suffering protagonist can't sleep.

* Non-plot variant in ''UnrealTournament'': in Assault mode's rules. The match consist of two rounds, one defense and one offense; if the attackers in the first round win, they swap roles with the defenders and the new attackers must win faster. Example: your team starts with offense. If you lose the offense round, you instantly lose the match. If you win the offense round but lose the defense one, you lose the match as well. Under the same rules, if you were to start with defense you could win the match either by winning defense OR losing defense but beating the other team's time in offense... but if you play against the AI, you always start with offense and therefore you can't afford to lose even once. This can be particularly frustrating since [[ItsUpToYou the bots on your team are severely handicapped in Assault mode]].

This trope is often the unsaid [[JustifiedTrope justification]] for having {{Showy Invincible Hero}}s.

** Of course, YourMileageMayVary.

** Its not much of a subversion: Sauron may fall, but SoLongAsThereIsEvil (which there will always be, since it was woven into the fabric of creation itself by Morgoth), "the shadow will ever take another shape and grow again."

* Environmental protection. Once damage is done and the natural state of a place is gone, its gone, and if recovery is at all possible, its usually too expensive and what comes back won't be what used to be there. The bill setting an area aside must be defended from illegal tresspassers and legal alterations every day of the year for the rest of time for its backers to get their way, but bulldozers only need to go through once for their backers to win.
** Only on a human timescale. On a geologic timescale recovery happens in the wink of an eye.

->Spike: ''We just keep coming. But you can kill a hundred, a thousand, a thousand thousand and the armies of Hell besides, and all we need... is for one of us, just one, sooner or later, to have the thing we're all hoping for.''
->Buffy: ''And that would be what?''
->Spike: ''One good day.''
-->--"Fool for Love," BuffyTheVampireSlayer

* Current antagonist Tsukishima in {{Bleach}} has powers that [[spoiler: would implant false memories of himself into a person, effectively making his victims geniunely believe he was their friend/relative/lover, etc]] if he could cut them once.

* In speeches about the 9/11 attacks and the subsequent WarOnTerrorism, GeorgeWBush and various officials have said this about Al Queda and other terrorist groups.

When Evil Only Has To Win Once, heroes need to step up their game because the SortingAlgorithmOfEvil just divided by zero. Usually this shows up in stories where there is some kind of repeating challenge against the forces of good; be it [[MortalKombat a martial arts tournament for control of the planet]], a resurfacing SealedEvilInACan, or just a laundry list of [[SortingAlgorithmOfVillainThreat progressively more dangerous enemies.]] You can expect TheChosenOne to feel the pressure — there are hundreds of {{mook}}s, dozens of mid-level bad guys, a [[TheDragon Dragon]], one BigBad villain — and one [[TheHero Hero]] (or [[FiveManBand a team]], but you get the idea) to face the threat. There's no one else to face the threat... [[ItsUpToYou usually, at least.]] Hopefully [[RagTagBunchOfMisfits the replacements]] can [[WeDoTheImpossible do the impossible.]]

'''In some stories, this won't happen.''' In some stories, [[TitleDrop Evil only has to win once]] in order to [[EndOfTheWorldAsWeKnowIt permanently turn]] the [[CrapsackWorld world into a crapsack]] VillainWorld with absolutely no [[EarnYourHappyEnding hope of being deposed]]. Heck, if the villain is an OmnicidalManiac [[ApocalypseHow there won't even be]] [[EarthShatteringKaboom a world to save]].

* In ''TheFifthElement'', the personification of evil springs up every 400 years. The titular element has to be used in conjunction with the four element stones to wipe it out, but it keeps coming back. If evil gets ahold of the four stones, however, it can wipe out all life in the universe. No recovering from that.

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* In ''TheFifthElement'', evil stops on by every 5000 years and only has to win once to wipe out all life in the Universe. If you are ever the savior, try not to screw it up.
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* Roland of ''TheDarkTower'' is seeking the aforementioned Tower to save it. [[spoiler:He's also stuck in a StableTimeLoop and must repeat his adventure over and over, meaning he has to save the Tower numerous times. In comparison, [[BigBad the Crimson King]] only needs to win once to destroy reality and plunge all its denizens into the primordial chaos.]][[/folder]]