History Main / SuddenlySignificantRule

* In 1987, the UsefulNotes/{{NCAA}} passed a rule change that allowed any conference with at least 12 [[UsefulNotes/CollegiateAmericanFootball football]] members to split into divisions and hold a championship game between the divisional winners, with said game not counting against either team's limit on regular-season contests. The rule was proposed by two Division II conferences but applied throughout the NCAA. The two D-II conferences that proposed the change ended up not implementing it immediately due to changes in that division's playoff format. However, Roy Kramer, then commissioner of the Southeastern Conference, one of the leagues that would eventually become part of the so-called [[UsefulNotes/CollegiateAmericanFootballPower5Conferences Power Five]], noticed that the SEC had 10 members. If it added two more... you get the picture. Cue the SEC adding Arkansas and South Carolina in 1991 and launching its championship game the next year. The game was enough of a [[MoneyDearBoy cash cow]] that every other [[UsefulNotes/CollegiateAmericanFootballConferences conference]] in what is now Division I FBS eventually [[FollowTheLeader followed suit]].

* In the last years of the UsefulNotes/WeimarRepublic none of the governments had a positive parliamentary majority behind them. However, the chancellor was appointed by the President and the President was allowed to make "Emergency Orders" (Notverordnungen) under Article 48 of the Weimar constitution. While they could be thrown out by a majority of the parliament voting against them, the President also had the power to dissolve the parliament at any point he pleased and call new elections. When parliament was not in session, the Emergency Orders could not be voided by it, and hence Brüning, von Papen, and Schleicher (the last three chancellors before Hitler) could in essence govern without parliament so long as the President supported their agenda. This backfired ''hard'' and the Nazis got more and more votes until eventually (after the Nazis got 45% of the vote and could get a majority with a coalition with another far-right party) President Hindenburg appointed Hitler chancellor. Hitler proceeded to introduce and pass a law giving him the power to make any laws he wished, including those going against letter and spirit of the constitution. The question of whether the "AintNoRule" justification the Nazis used was legit has never been conclusively answered, but suffice to say the constitution of UsefulNotes/TheBonnRepublic and UsefulNotes/TheBerlinRepublic (which is the same document in essence) is anally retentive about none of that ever happening ever again.

** In ''Literature/UnseenAcademicals'', one of the more absurd-seeming of the foot-the-ball rules is "The ball is the ball that shall be known as the ball". This comes in handy in the big match, when Trev Likely, who has never practiced with a spherical ball but is a master of kicking a tin can, uses it to say that, as long as the team ''treats'' the can as the ball, it's the ball.

* A bit spoileriffic example from ''Manga/TheLawOfUeki'': The characters get special powers to participate in a tournament to decide who's gonna be the next God (since the current one wants to quit). There are two rules: If a participant attacks a normal person with his powers, the attacker loses one sai (talents, unique qualities of every person), and losing all your sais means you stop existing; but after a tournament fight, the winner gets a new sai. This becomes irrelevant after the first stage since the rest of the tournament is held up in Heaven, there's not normal humans outside of contestants, and everyone who got that far already won a lot of sais. [softreturn] Cue to the climax, the BigBad gets cornered and [[spoiler:gets out of the tournament, meaning that every time the Hero attacks he loses one sai.]] Meanwhile, the Hero [[spoiler:ends up down to one sai, with another hit he will win the fight but also his existence will end. He attacks anyway but doesn't disappear because in the middle of the fight, he accidentally blasted away a poor ComicRelief, which gave him an additional sai.]]
* In the {{TabletopGame/Mahjong}} manga ''"Tetsunaki no Kirinji"'' the main protagonist is almost certain to win an important match with a great starting hand, however he is so distracted by his great fortune that he didn't notice the other 3 players discarding the same wind tile and he discards the fourth, meaning the match is aborted. This is due to the "consecutive four wind discard" rule, that every mahjong player knows but it simply never appears in normal gameplay and thus the protagonist was careless in a crucial moment, wasting his almost guaranteed victory.

* In an ''ComicBook/ArchieComics'' scene at Veronica's backyard pool, Veronica is scheming to get rid of Betty so she can have Archie all to herself. When Betty pushes a fully dressed Archie into the pool, Veronica promptly has her banned from the pool area for the day, citing a "No horseplay" rule. Betty agrees, but slyly points out that Archie has to leave ''with'' her since he violated a rule against being in the pool with his clothes on!

* ''Fanfic/ADiplomaticVisit'': In chapter 5 of the sequel ''Diplomat at Large'', Twilight invokes a law dating back to the first Noble Council -- "In the time where our allies are under attack, all those who deliberately deny or delay Equestria's support on their own volition and actively act against the principles of friendship that our nation was founded on, shall have their wealth and citizenship revoked, and be held prisoner until such time that the conflict is over as to not pose as a potential enemy within our own nation." In short, it lets her ''legally'' remove a majority of the nobles from power so the Princesses can declare war on the Storm King and his armies without interference. This rule is ''literally'' over a thousand years old and is still on the books, but she found it and made use of it. It later turns out that it wasn't actually ratified, though by that point Blueblood's gathered enough evidence of wrongdoing to have them all legally removed soon enough ''anyway''.
* In ''Fanfic/HisHonorTheMayorDrewLipsky'' Shego's attempt to write Drakken in as a joke candidate in the Middleton mayoral election results in [[GoneHorriblyRight him getting elected.]] Kim tries to use Drakken's criminal record to have him disqualified, but due to a rule dating back to the city founding regarding what crimes do and don't disqualify an official from the position nothing in Drakken's record counts.
* The Golden Fist Fighting-type Tournament in ''Fanfic/BoldoresAndBoomsticks'' has a long-forgotten rule allowing [[Franchise/{{Pokemon}} Black Belts and Battle Girls]] to compete against the Pokémon in the tournament, as a means of testing their strength. This is used to allow [[WebAnimation/{{RWBY}} Yang Xiao-Long]] to compete, while a provision allowing martial artists to use weapons was used to let her use Ember Celica in the finals.

* In ''Literature/DragonBones'', Ward is told that a slave has fled to his land, Hurog, and is hiding somewhere under the castle. The nobles who lost the slave would like to get her back, but Ward tells them that there is no slave, invoking an ancient law that says that a slave who sets foot on Hurog land is automatically free. Ward's father and grandfather were jerks who would have happily assisted the nobles in their search for the escaped slaves, but Ward decides to revive the tradition. The nobles are quite annoyed.
* From ''Literature/TheElenium'', Berit is a Novice, so he's not entitled to wear armour yet. When Sparhawk and company head off to Zemoch, they dust off the seldom-used rank of ''Apprentice'' Knight for Berit, which means he's not a full Knight, but ''is'' allowed to wear armour.

* In ''By the Sword'', a [[Literature/HeraldsOfValdemar Valdemar]] novel by Creator/MercedesLackey, there's an old rule that says that a mercenary company that has lost enough members can call the Captaincy to vote. The Captain of the Skybolts, Ardana, gets the boot after a disastrous campaign.
* In ''Literature/TheBelgariad'', there is a clause in the Accords of Val Alorn with Tolnedra that says "Aloria shall maintain Riva and keep it whole." Thing is, at the time the treaty was signed, Aloria (the ancestral kingdom of the Alorns) hadn't existed in centuries: what was once that nation was split into the kingdoms of Riva, Drasnia, Cherekh, and Algaria. The last three each have peace treaties with Tolnedra. This clause comes into effect much later, when the Emperor, angered by a disastrous expedition to Riva, prepares for a full-scale invasion. The [[{{Ambadassador}} Cherekh ambassador]] (fully aware of the accords) sends a letter to the Emperor saying that if this invasion happens, Aloria will fulfill that clause and end Tolnedra. The Emperor realizes that while Drasnia, Cherekh, and Algaria have signed individual treaties with Tolnedra, ''collectively they are Aloria'', with whom Tolnedra has no treaties at all. The fear that the Alorns might band together to make war haunts the Tolnedran government for ''centuries''--and then Nyissan assassins murder the Rivan King, and Tolnedra's nightmares come true.
** One of the clauses in the Treaty of Vo Mimbre is that a Tolnedran Princess must come to Riva and await for the King to return. Ce'Nedra is ready to go through this formality that pays homage to a long-extinct dynasty [[spoiler:and discovers that Garion is the rightful Rivan King.]]

* In ''Literature/TheKnightsOfTheCross'', when all other ways to extricate [[DistressedDude Zbyszko]] from his pending execution fail, princess Anna remembers a little-known law that a young man cannot be executed if a pure maiden claims him as her betrothed. Resulting in an iconic scene of [[LoveInterest Danusia]] doing just that.
* ''Literature/HaloFirstStrike'': The Cole Protocol is a series of rules drafted for human fleets listing numerous steps they must follow to prevent [[ScaryDogmaticAliens the Covenant]] from finding Earth, such as never hyper-space jumping directly to Earth, destroying navigation intel, etc. One of the rules, Subsection 7, said to never bring back a captured Covenant vessel without thoroughly checking it for tracking devices first. However, it was mostly ignored because not until the 27th year of the war did anyone ever capture a Covenant vessel without [[TakingYouWithMe its crew hitting the self-destruct]].

* In the''Literature/WorldOfFiveGods'', trying and failing to perform death magic on someone is legally attempted murder and punishable by execution. ''Successfully'' performing death magic, on the other hand, is legally a miracle of divine justice and not punishable. Since a succesful death miracle ''also'' inevitably kills the caster, this is mostly just a priestly technicality... until Cazaril petitions for a death miracle, gets one, and then survives due to the effects of a second miracle.

* In ''VisualNovel/TheGreatAceAttorney'', any jurist on the jury can declare their verdict at any time, if they feel the truth of the case is clear. If, at any point, all six jurors are unanimous in their verdict, the trial immediately ends. However, the first time this happens (with all six jurors voting guilty against the protagonist Ryonosuke's client), his assistant points out that, according to an ancient law, the defence has the right to a "summation examination", where they can interview the jurists and attempt to persuade them to change their verdict. All present are stunned, since, while the law has been on the books for ages, no one has ever bothered to use it in recent memory; the prosecutor even argues that the law is clearly defunct as a result, having fallen into obvious disuse. However, the judge rules that the law is still valid and, as a result, the defence makes heavy use of it for every subsequent trial that includes a jury.

* ''VisualNovel/TheGreatAceAttorney'': The right to a closing argument is a mostly forgotten rule that was only discovered thanks to the use of an out-of-date law book.

* In Creator/LoisMcMasterBujold's ''Literature/VorkosiganSaga'' novel ''A Civil Campaign'' the nobleman Count Vormuir from the somewhat socially and legally backward and decidedly SchizoTech planet Barrayar hits upon the "brilliant" scheme of providing for more subjects for himself by harvesting unwanted eggs from the reproduction clinic in his district capital and personally providing the sperm, with all resulting children born in {{Uterine Replicator}}s. All of them are girls (to take further advantage of the fact that the introduction of advanced genetic technology to Barrayar has resulted in a noticeable imbalance in the number of boys to girls in that traditionally patriarchal society). Under existing Barrayarn law, every single one of these children are Vormuir's acknowledged bastards, and he claims legal custody. The planetary emperor is forced to allow Vormuir's custody claim--but dusts off the old laws regarding the duty of a high-born father to provide dowries for his acknowledged female bastards--in Vormuir's case, ''one hundred and eighteen'' dowries.

* An episode of ''WesternAnimation/TheSimpsons'' hinges on this. When several vocal townspeople protest alcohol consumption and demand prohibition, the city officials are ready to dismiss them out of hand until a clerk in the room happens to find a 200-year-old prohibition law that was passed but had never been enforced. Funnily enough, this is [[InvertedTrope inverted]] at the end of the episode when the same clerk finds on the same parchment that the law was repealed a year after being put in place, invalidating Homer's crimes.

* The Golden Fist Fighting-type Tournament in ''Fanfic/BoldoresAndBoomsticks'' has a long-forgotten rule allowing [[Franchise/{{Pokemon}} Black Belts and Battle Girls]] to compete against the Pokémon in the tournament, as a means of testing their strength. This is used to allow [[WebAnimation {{RWBY}} Yang Xiao-Long]] to compete, while a provision allowing martial artists to use weapons was used to let her use Ember Celica in the finals.

* ''VisualNovel/PhoenixWrightAceAttorney'': The issue of evidence law comes up in the fifth episode. Previously nobody have had to worry about how evidence was presented to the trial.

* The old "tuck rule" used by the UsefulNotes/NationalFootballLeague from 1999 until 2013, where if a passer's arm is going forward when he is being hit and loses control of the football it counts as an incomplete pass rather than a fumble, even if his arm is going towards his body to tuck the ball away for ball security. It had been on the books for a couple years, but most football fans will remember it for affecting the outcome of the "Tuck Rule Game", the AFC Divisional Round game in the 2001-02 playoffs between the Oakland Raiders and New England Patriots. Raiders are up 13-10, but the Patriots are able to get to Oakland's 42-yard line with 1:50 left in the 4th quarter. Patriots quarterback Tom Brady then gets hit while bringing his arm forward and loses the ball, which the Raiders recovered. It was initially ruled a fumble, which would have meant the Raiders would win because they could run out the clock as the Patriots had no timeouts, but the referees pulled in the tuck rule to rule it an incomplete pass, letting the Patriots keep the ball. With the second life, the Patriots got into field goal range and tied the game, before winning in overtime and going on to win the rest of the way to the Super Bowl, starting the Patriots dynasty. Patriots coach Bill Belichick remembered that rule in particular as the Patriots had been on the other end of that ruling earlier in the season back in September against the New York Jets where Jets quarterback Vinny Testeverde had lost the ball on a similar play as the Jets were driving down but the tuck rule meant the Jets were able to continue their drive, kick a game-tying field goal, and later win the game.

* ''Literature/HaloFirstStrike'': The Cole Protocol is a series of rules drafted for human fleets listing numerous steps they must follow to prevent [[ScaryDogmaticAliens the Covenant]] from finding Earth, such as never hyper-space jumping directly to Earth, destroying navigation intel, etc. One of the rules, Subsection 7, said to never bring back a captured Covenant vessel without thoroughly checking it for tracking devices first. However, it was mostly ignored because not until the 27th year of the war did anyone ever capture a Covenant vessel without [[TakingYouWithMe its crew hitting the self-destruct]].