[[caption-width-right:300:[[ComicStrip/CalvinAndHobbes Sometimes]] it's a law of the internet that makes one think "ThereShouldBeALaw"...[[note]]And, yes, there are porn versions of this image. Like the rule says, NO EXCEPTIONS.[[/note]]]]

%%% When we are defining a rule, the rule definition comes first.
%%% Save the quotes for the Quotes page.
'''''If it exists, there is UsefulNotes/{{porn|ography}} of it -- no exceptions.'''''
%%% When we are defining a rule, the rule definition comes first.
%%% Save the quotes for the Quotes page.

Allegedly originating from and popularized by the {{imageboard}} Website/FourChan, this was the very first near-universally agreed-upon [[RulesOfTheInternet Rule of the Internet]]. It is so well founded and documented with ''[[TwentyPercentMoreAwesome irrefutable proof]]'' that even those with only a cursory awareness of the Internet are aware of this rule even if they don't know it has a name.

While the original architects of the Internet had grandiose goals of research and data sharing, [[TheRuleOfFirstAdopters we all know what Joe Everyman]] is going to use it for: [[TheInternetIsForPorn pornography]]! Now, it's not that everyone online is just looking for pornography; it's just that it's very ''very'' easy to [[HehHehYouSaidX come]] [[DoubleEntendre to]]. Even if you're not looking for it! Don't believe us? [[SchmuckBait Do a Bing image search (filters off)]] of, well... pretty much anything. Sometimes even with the filters ''on''. Odds are pretty good that the results will include something NotSafeForWork.

The key reason the scope of it is so wide and bizarre lies in what some have come to call '''''Rule 36''''': "If you've thought of it, then there's somebody out there with a [=fetish=] for it." (And incidentally, by "it" we mean "anything that exists in the world.") Even Wiki/TVTropes.

There's also ''Rule 35'', basically [[MortonsFork a guarantee that Rule 34 will remain true]] because "if there is no porn of it, it ''will'' be made." This basically means that if you notice you can't find porn of something, and point it out, [[SelfFulfillingProphecy somebody will be happy to draw/write/find it for you in pretty short order]], if only to maintain the Rule 34.

Finally, Rule 35 also has a quantum interpretation. "Referring to a type of previously non-existent porn will cause online porn of that type to come into being retroactively." Nobody takes this seriously, so far as we know.

You might wish to keep a bottle of BrainBleach handy while proving (or [[SchmuckBait attempting to disprove]]) Rule 34. [[ConditionedToAcceptHorror Don't say we didn't warn you]]. And if you DO go hunting to prove this rule false, [[HarmfulToMinors say good-bye to your childhood]] first...

An OlderThanDirt trope as decades before the Internet was even conceived, publications known as "Tijuana bibles" circulated widely, featuring X-rated (and copyright-infringing) cartoons showcasing a mix of popular cartoon characters and movie stars of the day doing the Rule 34 thing.

Compare SexyWhateverOutfit (a non-pornographic SisterTrope), MemeticMolester, PerverseSexualLust, [[http://[=fetishfuel=].wikia.com/wiki/Fetish_Fuel_Wiki the fetish fuel wiki]], RuleThirtyFourCreatorReactions (a list of creator reactions to this applying to their work). See also RuleSixtyThree, which is both often confused with this and [[SisterTrope constantly overlapped]].

[[JustForFun/IThoughtItMeant Not to be confused with]] these other rule 34's (though overlap with this rule is guaranteed):
* US federal courts' [[http://en.wikipedia.org/wiki/Request_for_production Rule 34]].
* Rule 34 of the EvilOverlordList (dealing with the trope ScaledUp).
* ''The 34th Rule'', a ''Series/StarTrekDeepSpaceNine'' book (the 34th Rule of Acquisition reads "[[WarForFunAndProfit War is good for business]]").
* [[http://xkcd.com/505 Wolfram]]'s Rule 34.
* Creator/CharlesStross' novel ''{{Literature/Rule34}}'' (although that title is a deliberate ShoutOut).
* [[http://lths.net Lyons Township High School]]'s rule book #34: No Pornography (which may or may not be a huge coincidence).
* [[http://deathnote.wikia.com/wiki/The_Rules_of_Death_Note Rule XXXIV]] of the Manga/DeathNote ([[OnlyICanKillHim Death Note Owners are protected from other Gods of Death]]).
* [[VideoGame/PokemonGoldAndSilver Route 34]] (Which happens to be the first place ever in any Pokémon game you could ''breed'' your 'mons, and Ditto, the ultimate Pokémon breeding machine, can be caught here.)
* [[{{Series/NCIS}} Leroy Jethro Gibbs]]'s Rule #34. While [[http://ncis.wikia.com/wiki/Gibbs%27s_Rules apparently not yet specified by the show,]] Gibbs has at least 69 rules, so a rule 34 undoubtedly exists.

See also GoneHorriblyRight. (You wanted porn? [[BrainBleach You're welcome]].)

'''No examples, please.''' Not only would such a list cover potentially every work ever, but we're also not interested in being the Net's "How To Find Rule 34 Stuff" -- you will need to look elsewhere if you want to find ''that kind of thing''. At most, you can see our pages for TheRuleOfFirstAdopters and ParallelPornTitles to witness how the rule applied even before the Web was invented.

And go to TheInternetIsForPorn for in universe examples.
[[SelfDemonstratingArticle Yes. There is porn of this article as well.]] [[GoMadFromTheRevelation No exceptions!]]

[[MadnessMantra no exceptions...no exceptions...]][[RuleOfThree no exceptions...]]