->''"This is highly improbable."''
-->--'''[[TheSpock Data]]''', ''Series/StarTrekTheNextGeneration''

Tropes that defy possibility (or [[ProbabilityTropes probability]]) in some glaringly [[FridgeLogic unexplained]] ways that may at least momentarily disrupt some viewers WillingSuspensionOfDisbelief ([[RuleOfFunny if]] [[RuleOfCool you]] [[RuleOfCute were]] [[RuleOfGlamorous even]] [[RuleOfScary trying]]), but may also be an AcceptableBreaksFromReality. Sometimes PlayedForLaughs with some LampshadeHanging.

This is a subindex of ProbabilityTropes, which deal with probability issues in general. This index specifically deals with the ''im''probable.

Note that this index is not for tropes that are intentionally magical, supernatural, rooted in common superstition, or have some other form of directly {{Hand Wave}}d AppliedPhlebotinum that would make them perfectly explainable in-universe in such a way that would preserve WillingSuspensionOfDisbelief intact. In fact, these tropes are often funnier or more effective when they're ''[[DontExplainTheJoke not]]'' [[DontExplainTheJoke explained]].

This index is also not for occurrences that are merely ''rare'', but only due to wildly complex human factors that involve the net results of the unpredictable actions of multiple people (economics, elections, popularity, sports, strategy, etc.). In such circumstances, a certain minimum amount of unforeseeable uncertainty is a given, and [[LogicBomb unexpected results are not unexpected]][[note]]And if we're talking human behavior, then there are those who would claim that it's really not ''that'' unpredictable[[/note]]. Odds should have to be [[MillionToOneChance truly astronomical]] to be in this index.

Some entries in this index are also examples of bad writing if played straight. But not all Bad Writing is necessarily unrealistic. Some devices of Bad Writing can derail a story in that they are boring, annoying or frustrating, but that doesn't make them inherently unlikely.

The index namer is from an episode of ''Series/StarTrekTheNextGeneration'', "Cause and Effect", where Data deals cards at a poker game and everyone at the table correctly predicts which cards they'll receive. In-universe, the characters observed how impossibly unlikely their predictions were turning out. Ultimately, it had [[AppliedPhlebotinum a cause]], but they did not realize that for [[StableTimeLoop most of the times]] they ended up getting blown up.
+ AbsurdityAscendant
+ AcceptableBreaksFromReality
+ ContrivedStupidityTropes
+ ImprobableAppearanceTropes
+ ImprobableBehaviorTropes
+ ImprovisedIndex
+ InDexMachina
+ MarySueTropes
+ MundanityTropes
+ ThereAreNoIndexes

* AbsurdCuttingPower
** AbsurdlySharpBlade
** AbsurdlySharpClaws
* AbsurdlyPowerfulStudentCouncil
* AbsurdlySpaciousSewer
* ApocalypticLogistics
* AssPull
* BambooTechnology
* BatDeduction
* BizarreAndImprobableBallistics
* BizarreAndImprobableGolfGame
* CantGetAwayWithNuthin
* CharacterDerailment
* ContainerCling
* ContrivedCoincidence
* CriticalResearchFailure
* CutTheFuse
* DeusAngstMachina
* ElevatorGag
* EveryoneIsGay
* FridgeLogic
* GenerationXerox
* GunFu
* HamsterWheelPower
* ImpossibleShadowPuppets
* ImprobableAccessoryEffect
* ImprobableAimingSkills
* ImprobableChopsticksSkill
* ImprobableParkingSkills
* ImprobableUseOfAWeapon
* ImprobablyCoolCar
* ImprobablyFemaleCast
* ImprobablyHighIQ
* ImprobablyLowIQ
* LampshadeHanging
* MagicPokerEquation
* MillionToOneChance
* OneDoseFitsAll
* OutOfContextEavesdropping
* PlotHole
* PrecisionCrash
* SeeTheWhitesOfTheirEyes
* SeriesContinuityError
* STDImmunity
* StuckOnBandAidBrand
* SuddenlySexuality
* TinyHeadedBehemoth
* UnlikelyHero
* VacuumMouth
* ViciousVac
* VoodooShark