Leet Speek, or "1337 sp33k" was this to bypass server filters on curse words.
Ain't No Rule against "Ghosting" or "Stream-sniping". Professional people often stream their games. Their opponents are well aware of this, and will join in their stream as an anonymous watcher or as a dummy-account and spy on their opponents when the game doesn't let them do it. Against the rules? Nope - Ain't No Rule saying you can't do it, since it's not part of the game itself.
Which is why some professional streams, if they don't quit streaming outright, purposely put in a delay (usually of about 30 seconds or so) to prevent this kind of thing from happening.
Referenced in Baldur's Gate II with a magic ring that fires a blast of fire. The text indicates it was used in a duel between two drow, where each was allowed the use of one magical item. It was used by a friend of one of them, who shot their opponent in the back from the stands. Being drow, everyone agreed it was a brilliant interpretation of the rules.
The World Ends with You has the entry fee, in which the Conductor takes from the player whatever is most valuable to him or her. The loophole is that the Conductor gets to choose what that entry fee is. In Week 2, he takes Shiki Misaki as the fee to hide the fact that he can't return her to life. In week 3, Kitaniji takes every other player from the game as Neku's entry fee because a player is helpless without a partner. This creates a situation so Unwinnable that even Uzuki and Kariya are doubtful of its morality. Thankfully, there was Beat, a Reaper who was willing to Heel-Face Turn.
Sim City 4 Deluxe can ultimately allow a player (through some basic building making and basic modding) to have apartments on light density zones and who knows what else. Sure, it says no apartments develop on light density, but who said anything about pencil towers or duplexes for that matter if you truly cared? In fact, half of modding the game is about ballooning zone densities to unbelievable sizes with building types.
In the Half-Life expansion Opposing Forces protagonist Adrian Shephard can avoid the order to kill Black Mesa personnel to cover up the incident because he never officially got that part of his orders. He should be able to reasonably deduce that part of his orders by asking (or just watching) the others, but remains purposefully ignorant.
Explicitly invoked by Aigis in Persona 3: "Nowhere in the school regulations does it state that canines are prohibited from attending school." It doesn't happen.
My World, My Way is built around "Ain't no rule" as a gameplay aspect. Why struggle when whining can change your situation?
Sissel invokes this in Ghost Trick. He can only go back to four minutes before someone dies. But Yomiel's body technically died ten years ago and stayed suspended at the moment of death until the meteorite was removed to make him truly dead. Sissel uses Yomiel's body to go back ten years into the past and avert the events that made Yomiel into a ghost in the first place, thus changing the entire timeline to save everyone.
Given that it was a widely-played MMORPG, World of Warcraft has had a few instances, some controversial, some not:
Given that this achievement is typically extremely difficult (or, depending on your class, nearly impossible), it's generally considered that the intended way of achieving it is through abusing the rather literal wording of the achievementnote All that's required is turning in the quest within 90 seconds of striking the crystal, namely the first objective that triggers the upcoming battle. You can turn in the quest to the NPC that spawns very closely. There is nothing actually stopping you striking the crystal a second time before turning in the quest.
One particular perk was available to warriors for a very short time after burning crusade was introduced: The new Commanding Shout skill increased the max life to everyone within its radius by 1680-ish HP, but also increased the current life by 1680 if the buff hadn't been applied yet. No big deal... except that it also buffed the current life back to 1680+1 if it fell below that amount, giving warriors on low HP basically a free heal every GCD for 10 rage. It got remedied rather quickly.
Another Loophole Abuse in the game was involving Warlocks. Demonology warlocks used to have a talent point where their active pet would give them a buff, and if they sacrificed it, they would be given a different buff to replace the one granted by the pet. However, one curious player who had invested in engineering attempted to use the goblin jumper cables on his pet, and to his surprise, the pet then came back to life and granted them the buff...while they still had the buff from sacrificing the demon on top of it. Other warlocks begun to try this too, although it was still a pretty low chance of success, it worked. It wasn't even removed in an Obvious Rule Patch, believe it or not - Blizzard even encouraged people to try it. It was removed before expansions, though.
Before it was removed, someone described a pretty creative use of Hello, Insert Name Here as a hunter. Ain't No Rule saying you can't give your pet the same name as you to screw up targeting macros.
Ain't No Rule against making a couple toons for PvP and then giving them really long names that're hard to type (and start with the same letter) or really similar names for the same purpose.
Griefing has had many loopholes....
"Rooftop camping". Before there was no rule against people with ranged attacks (especially hunters) standing on the roof of a building in contested territory and firing. Normally, guards should have been able to come in and hurt them, but since the guards could not get up to the roof, couldn't do anything to stop players from picking off others on the ground. Duskwood was the best place to do this because there was a ledge where you could jump onto a roof and the guards woudln't spawn. However, they would normally die from you and not suffer durability loss - in Gadgetzan, it was far more annoying, because people would just shoot one person and then feign death as the guards run over and pummel the poor player to death. Snipers were added on the roofs to prevent this.
In neutral Goblin cities (Booty Bay, Ratchet, Gadgetzan, Everlook), Rogues would often grief players by sneaking up to them, sticking a knife in their side, and then vanishing while the guards beat up the player who was busy wondering what was going on.
Ain't No Rule against kiting ridiculously strong monsters into capital cities.
Before it was given to Mages as a talent, a boss in Molten Core named Baron Geddon would make a certain raid member a "living bomb" which would cause them to eventually explode and damage all people nearby. He could also do this to pets, too - and people realized that you could get past this by simply dismissing the pet. However, one time a hunter did this and then called it out in the middle of a heavily populated city...and he still had the living bomb debuff. A few seconds later, there was a mountain of corpses in the middle of the auction House. Cue people replicating this until it was fixed in a patch.
The famous Corrupted Blood Incident resulted from a hunter taking an infected pet into Ironforge & Orgrimmar and spreading the plague across the cities.
Which was studied by the World Health Organization as an actual epidemic outbreak due to people purposely spreading the plague and many trying to stave the outbreak by quarantining themselves, killing players trying to spread the plague, or healers trying to save lower level players.
Ain't No Rule against putting a single item for sale at a huge price so people buying stuff for crafting professions accidentally buy one item instead of a full stack.
In one instance, a programming oversight resulted in a Worgen mob being able to be tamed. So a bunch of hunters eventually caught and tamed this pet. Unfortunate Implications resulted as Worgen became playable characters around this time..
Especially since "What's Worgen backwards?" was a LONG standing joke by that point.
Ain't No Rule against bringing friend(s) into the Raid Finder and have them roll on gear they don't need to increase the chances that you'll win it.
A rare positive example that could honestly have been done in any game (and has been rumoured to have been done in Majora's Mask before), a player in a guild had a buddy who was rendered blind by an accident while stationed in Iraq. He regularly performs very well in-game, so how does he do it? The blind player and his friend acting as a "Seeing eye dog" used mods, macros, and private-sound channels so that he could play the game blind.
Humans in Mass Effect under the Treaty of Farixen are only allowed to build one dreadnought per every five the Turians have. Instead they began building carriers which were not subject to any restrictions. This was mostly because Humans were the ones to introduce the concept of Carriers to the Galaxy in the first place.
In Mass Effect 3, there are several ways the quarians try to get around this rule: they were arming every single ship they had so even the huge ships would be armed (and as such weren't purpose-built dreadnoughts), they were salvaging destroyed dreadnoughts thus making what the quarians were doing technically rebuilding them, the Council is too busy prosecuting the war with the Reapers to pay attention to them, and if the council wasn't, the quarians signatures were effectively removed from the treaty when they lost their embassy and they largely operate outside the Council's jurisdiction anyway.
Doctor Chakwas was the only member of the Normandy crew in the second game to not face any formal charges for working with Cerberus because she had gotten a proper leave of absence from her previous post and refused to accept payment for working as the Normandy's doctor. Though she does acknowledge that if Shepard had actually been judged a war criminal she likely would have been tried as an accessory, so she got lucky there.
Metal Gear Solid has an interesting one. There are laws limiting the use of nuclear missiles. Metal Gear Rex uses a rail-gun to fire nuclear warheads.
In Disgaea 2 you will repeatedly be subpoenaed by the Dark Court for various "crimes" committed by your party members. This being the Netherworld, you want to have extensive crime records, since it gives benefits. While the rules stipulate that a person has to find and enter the gate to the Dark Court, it doesn't actually have to be the person who did the crime. It also doesn't say only one person has to go in - you can form a ladder and throw up to nine people before the judge, who will write up everyone for this underhanded behavior.
Played with in Inazuma Eleven 3, when Coach Kudou forbids the entire team from going outside to practice or play soccer. To Endou, no soccer is probably as bad as having no food to eat, so he grows restless and starts kicking a soccer ball around indoors. Several of his teammates notice and realize that Kudou only forbade practicing outside, so they start doing Improvised Trainingindoors, as silly as that may sound. But then it turns out this was exactly what Coach Kudou wanted them to do, as being able to control and keep possession of the ball within tight boundaries would turn out to be extremely useful against their next opponents' tactics.
In RuneScape, the "Falador Massacre" was a result of a player abusing a glitch. The first player to reach level 99 of Construction held a party in his house. Eventually, so many players flooded the house that it crashed and booted them all to Falador. However, players inside the arena in the player's house were still flagged for PvP (which the other players weren't, and was disabled in that zone at the time) and proceeded to go on a killing spree.
The Cavern of Transcendence trial in City of Heroes required a team to get through the enemy-filled caves beneath the Hollows and then enter the Cavern, a massive room filled with monsters, and then activate 8 triggers (one for each team member) simultaneously that were spread throughout the room, in 90 minutes after receiving the mission. The obvious intended challenge was obviously for the team to fight through the caves, then clear out the monsters before activating the triggers. However, activating the triggers is all that's required to actually successfully complete the trial. A standard tactic quickly became having one team member with superspeed (which has a stealth benefit) and/or flight plus invisibility or some kind of stealth power, and recall (teleporting one teammate to your position) race through the caves, past all the enemy mobs, to the Cavern door and teleport in teammates. Upon entering the Cavern, the stealth teleporter would go to each trigger in turn and bring in a teammate, again without alerting any of the monsters. End result? A 90 minute trial that could be finished in a few minutes without having to engage a single enemy.
A shortcoming in the engine that supported Defense of the Ancients: All-Stars allowed players to kill their own mobs. So what this encouraged was someone to stay behind and kill every single one of "Their" mobs so the enemies couldn't get experience at all, and thus the "Deny" mechanic was born.
The sequel by Valve added a pause feature so people don't have to have a Bladder of Steel (or in case something happens that makes their game client crash.) don't cost their team the game. In order to prevent people from using this as an excuse to pause the game and plan ganks or other elaborate plans, any person can force-unpause the game. However, this appears to have encouraged the perverse Double Standard that whenever the afk player is on their team, the other team will wait for them...and whenever they're on your team, you can practically hear the other team saying, "Ain't No Rule saying we can't constantly force-unpause the game and get further ahead while they're gone." This has been somewhat addressed by not allowing the other side to unpause for a certain amount of time, if they do it enough which brings back the original problem.
In-game example in The Elder Scrolls V: Skyrim: If you use Thu'um shouts within the view of a hold's guards, they'll get on your case and tell you to stop that "... shouting thing". If you take the "Make me" route in the dialog, they say there isn't any rule really, and then cut off with "I'm watching you..."
League of Legends often gives deals to get champion skins for free. However, if you do not have the champion in question, you can still get the champion and the skin for free.
Related, PC gamer magazine often runs a code to receive a freebie for a game in its magazine, such as a free pet in Guild Wars or a free champion (and a skin) in League of Legends. There's always at least one person who goes onto their forums and asks them for a new code because theirs didn't work - Ain't No Rule saying people can't just go into a magazine store, take a copy of the magazine, snap a picture with their phone or write it down, and then enter it into the game without having to pay a cent for the magazine.
Newer issues of PC Gamer (The UK Version anyway) now comes in a sealed plastic or cardboard sleeve to stop that sort of thing.
A Master is given the power to summon one Servant, and if he loses it he can form a contract with a Servant whose Master was killed. Ain't No Rule that he can't form contracts with multiple Servants at once.
There does seem to be a rule that one Servant can't summon another, but the Grail's punishment is simply to make it a fake Servant who can still fill the role nicely enough.
Ain't No Rule that the supervisor of the war can't compete in the war.
The Berserker class has probably never been used for its original purpose (powering up a weak Servant to usable levels), with every known Master opting to make a powerful Servant even more powerful.
Ain't No Rule that you have to wait until the war begins to summon your Servant.
Broken Phantasm is a technique that releases all the power in a Servant's legendary weapon at once, destroying it in the process. Ain't No Rule that you can't use it with temporary copies of weapons.
From the 3rd Holy Grail war in the backstory and Fate/hollow ataraxia: Ain't No Rule that you can't apply your family's "cast spells twice" ability to the ritual that summons Saber. Meanwhile, the summoning of Angra Mainyu as Avenger was an attempt at Ain't No Rule that suffered from Epic FailandGone Horribly Right (They tried to summon the god of evil and got a random guy whom early humans used as a scapegoat, who has no powers and only qualifies as a Servant by being the embodiment of humanity's wish for evil to exist in a form they can see. When he dies his spirit enters the Grail... which grants wishes.).
One example not related to the Grail War rules: in Fate/Zero, Kiritsugu puts himself under a geas that he will not harm Kayneth, provided that Kayneth gives up on the Grail and kills his Servant. Kayneth agrees and does so... and is immediately shot dead by Kiritsugu's ally. After all, Kiritsugu himself did not harm Kayneth.
The Grail War is full of loopholes because many of the rules were made by the Mages' Association and Holy Church, but the Grail only follows it's own rules. As far as the Grail is concerned, there ain't no rule Masters have to be chosen from members of either of those organizations, or that their Servants have to recognize their rules.
Similar to Germany before World War II (see Real Life example below), USSR in Red Alert 2 manages to build up a large military partly through this trope. One of the restrictions is the limitation on military aircraft. So, the Soviets build thousands of armored zeppeling to act as bombers. Ain't No Rule about mind-controlling giant squids to sink Allied ships, right? Having powerful psychics under your command means you can have every Allied inspector come back saying exactly what you want him to say, even if he just saw a column of Apocalypse tanks roll by.
Tin Star has an example, with the sheriff Tin Star trying to figure out how to deal with an invasion of bandits dressed up as women without breaking the code "never shoot women and children".
Mo: Now what do we do, Tin Star? Why are you looking at that Good Guy Code of the West?
Tin Star: Looking for loopholes. Aha!
Tin Star: It says here "never shoot women and children."
Mo: Yeah, so?
Tin Star: So these are just women on their own! Get my guns, Mo!
Used to thwart the fal'Cie's plan in Final Fantasy XIII. The l'Cie's focus was to destroy Cocoon by killing Orphan, the fal'Cie responsible for providing the rest of the Cocoon fal'Cie with the power needed for maintaining Cocoon's vital functions. The Focus didn't say anything about what they could do after they accomplished this task, which is the loophole Fang and Vanille abuse to save Cocoon from crashing into Gran Pulse and killing its entire populace as the fal'Cie wanted.
The fal'Cie themselves are notable loophole abusers: while possessing immense power, they are inescapably bound to the purpose for which they were created, and cannot act outside said purpose. Humans, however, have no such limitations, so what do the fal'Cie do? They empower humans and manipulate them into fulfilling their goals.
The Professor Layton series absolutely adores this trope. With each game's puzzle collection, you can expect at least 20% of it to be comprised of puzzles that can only be solved by exploiting loopholes in the rules.
In Return To Zork, when you're about to finish the game, you can simply go on a killing spree. No wait, The Guardian will not allow this. However, you can simply stab them, drop all your items (That he'll take) so the Guardian will confiscate your nothing. Then you can pick all your items up, and go on a rampage.
In Monster Girl Quest, there's a commandment handed down by the Goddess Ilias, one commandment out of many of course. The commandment is that humans must never give their semen to monsters by sexual intercourse, since monsters are "evil" and such an act is taboo. Alice abuses a loophole when she wants to give Luka a good time before his fight with the Monster Lord, who is Alice herself: Alice has a "human form" she can transform into, and because she has intercourse with Luka in her human form and not her monster form, Luka isn't breaking the commandment when they have sex. Meia the mermaid and Sara the human also engage in sexual relations with Luka the protagonist, but more loophole abuse comes into play: Meia gives Luka a blowjob; she doesn't actually have intercourse with him, so the commandment isn't broken. And Sara also just gives Luka a blowjob, but even if they had sex it wouldn't matter since Sara is human. So the only actual intercourse that canonically happens without losing a fight is the one with Alice, who is in her human form when they do it.
Touhou's Marisa Kirisame has promised that all the youkai she's "borrowed" spellbooks from can have them back when her short human life ends, either by death or by becoming a youkai herself. One of her works-in-progress, occasionally seen in background material? An Elixer of Life.
Some online games have cracked down on mods because a lot of players would say "Ain't No Rule I can't just mod the game so that it plays for me or gives me an advantage."
On a similar note, games with glitches, exploits, or just plain overpowered moves/characters that are impossible to counter are heavily abused in online games while the people who use said exploits shrug their shoulders and wonder why people are making a fuss over something everyone can easily do.
Random Number Generator, or RNG abuse, in Pokémon games. As long as you have the right computer software, you can catch or hatch a mon with perfect stats, even a shiny one, quite easily.
Many builds of the Shifter class from Neverwinter Nights involve taking a few residuals levels of Monk, in order to catch feats, armor class based on the wisdom modifier and competency with the unarmed shapes. Because only a few levels are needed, this would incur in a nasty XP multiclass penalty if you are not human or half-elf. Some crafty players pick elves nevertheless (whose favored class is Wizard) and essentially forget about multiclass XP penalty at druid level 5. Shapeshifting overrides the current race by the race of the creature, and thus the preferred class of the creature (which is the same as humans usually, that is, the class with the highest level).
The Witch's House: There is a note on the third floor warning Viola not to be distracted in the following corridor, and walk in a straight line to the exit. If the player doesn't ever read the sign, they can go off the straight line as much as they want: ignorance of the rule excuses you!
Grim Grimoire uses this at the very end as the capper to Lillet Blan's rise to Magnificent Bitchhood. You see, whenever a major demon like Grimlet is summoned, you are allowed one wish from that demon in exchange for your soul - the demon, of course, is imprisoned in hell if it ever fails, or refuses, to fulfill this wish. Nothing is ever said as to the context of the wish... and Lillet exploits this loophole to eliminate him by asking him to embrace God. Advocat exclaims afterwards that he never felt such joy in a hundred years.
In Bioshock Infinite Father Comstock loves to abuse loop holes, particularly ones in the Bible, to justify his violence and racism. Comstock also only describes the United States as the Sodom Bellow when referring to it in terms of Columbia's secession, because he justifies the secession by arguing that the U.S. had become so corrupt from its founding principles that it was no longer really America any more. In this light, technically Columbia did not secede, it became the United States and cast out everything on the ground from the Union.
The Lord Forgives all, but I'm just a prophet. So I don't have to. Amen.
In Fallout: New Vegas, one of the sidequests you can undertake from the NCR's Mojave Outpost is to clear out giant ants at an intersection. Do that and inquire about a reward, the Ranger who gave you the quest will state that he said nothing about a reward and that NCR can't legally sanction mercenaries - right before he hands you some supplies anyway, stating that he's "misplaced" all of that.
Danganronpa is full of these: Monobear is happy to admit that he deliberately introduces rules including exploitable loopholes, partly because he is strictly bound by them too. Some of these include:
To get into Hope's Peak Academy, you need to be a high school student with an exceptional talent. Ain't no rule that the talent in question has to be academic or even productive, meaning that the class includes a talented "gamer", "yakuza" and "hall monitor".
In the first game, Monobear introduces a ban on students lending their ID cards to each other. Ain't no rule that you can't borrow or steal an ID card; and, in fact, Monobear leaves the dead students' ID cards in a publicly accessible box in the school lobby where anyone can pick them up.
Another of Monobear's rules: you can't break down locked doors. Later in the game, though, :the students break down a door into a sealed changing room, because it was barred, not locked.
Any student who kills another and then is discovered at the trial faces execution, but ain't no rule that they actually have to die. Towards the end of the game, Alter Ego and Kirigiri manage to disrupt Naegi's execution and bring him back into the school, causing Monobear, who can't break the rules to execute Naegi again, to fly into a rage and allow himself to be tried, which sets up the ending of the game.
Until the 1990s, South Korea banned all Japanese products from entering the country. Nintendo got around the ban by abusing a loophole whereby products sold by Korean companies were considered Korean. Nintendo commissioned Hyundai Electronics and later Daewon to distribute its products in Korea. Since Hyundai and Daewon were Korean companies, that effectively made Nintendo products distributed by them Korean products, thus avoiding the ban.
Valkyrie Crusade gives you bonuses for posting achievements to Twitter. The idea is to spread the word about the game and get rewarded in exchange. However, the game only checks that you've sent a tweet, not whether you've preserved the contents of the original tweet, such as the link to or the name of the game; you can make a spoof of the tweet, change it completely, or send it as a direct message to yourselfnote Direct Messages on Twitter can be sent in the form of "D <recipient> <message>", and can be done on anything that lets you write a tweet and send it.. Another option is to make an alternate Twitter account exclusively for game-related spam and send your tweets there. Of course, there's a catch; whether you use the tweet function properly or not, each type of achievement will only yield bonuses once per day, to prevent abuse.