->''"Any first day chemistry student could have told Ragby never to put sparks near a mystery gas. Unfortunately, Ragby had never met any first day chemistry students, so it came as a complete surprise to him when the gas passed by Mulch Diggums ignited in a chain of miniature explosions."''
-->-- ''[[Literature/ArtemisFowl Artemis Fowl: The Atlantis Complex]]''

Because most viewers have basic common sense, one would usually expect the same from characters on TV shows. [[IdiotBall Any negative deviation from such]] usually prompts a FacePalm and the comment "What an idiot!" or similar, hence the entry name.

Can cause ATragedyOfImpulsiveness, if the situation becomes more serious. It is also the usual reaction to a character demonstrating especially severe GenreBlindness. Taking this to the next level, where a character dies or very nearly dies because of their stupidity, is being TooDumbToLive.

Can also be a response to ineffectual contestants on a GameShow.

And please, as tempting as it is to defend your favorite show from forcing the IdiotBall into its characters' hands, refrain from making Administrivia/{{Justifying Edit}}s. With a CardCarryingVillain or IdiotHero, a few of these are to be expected. If the entire show has an IdiotPlot, it goes on that page instead. Also, ''do not assume that something listed here automatically makes it a bad episode''; it is usually more along the lines of "something else that is better could have been done". And, of course, some characters are ''supposed'' to be idiots, in which case we probably don't need a full and complete list of every stupid thing they do; a brief summing up would be more helpful.

Compare: IdiotBall and VillainBall.

There are also other examples which do not fit the standard idiocy.

'''Warning: Spoilers ahead!'''
* [[WhatAnIdiot/{{Anime}} Anime and Manga]]
* WhatAnIdiot/ComicBooks
* WhatAnIdiot/{{Disney}}
* WhatAnIdiot/FanFic
** WhatAnIdiot/MyBravePonyStarfleetMagic
* [[WhatAnIdiot/AnimatedFilm Film - Animated]]
* [[WhatAnIdiot/{{Film}} Film - Live-Action]]
* WhatAnIdiot/{{Literature}}
* WhatAnIdiot/LiveActionTV
* WhatAnIdiot/ProfessionalWrestling
* WhatAnIdiot/{{Theatre}}
* WhatAnIdiot/VideoGames
* WhatAnIdiot/WebOriginal
* WhatAnIdiot/WesternAnimation
* WhatAnIdiot/{{Other}}