A hilarious variation occurs in Schlock Mercenary, where the crew of the mercenary ship effectively avoid any litigation by becoming legally appointed bounty hunters, hunting members of the lawyer collective. They could still be sued if anyone apart from them used non-Collective attorneys, but Massey is the only non-Collective lawyer we've seen, and he's a member of the company.
Presumably, after this strip there's now a company policy regarding air vents, where there wasn't one previously.
Black Mage: We're going to grab the non-fabric of this anti-space time and rip it a new one.
Red Mage: Is that even possible? I'm not sure this place actually exists.
Black Mage: Then there's no rule that says we can't.
In the webcomic Brat-Halla, there ain't no rule saying that a god dueling another as a tie-breaker in the Pantheon Games can't call in his independently sentient, disembodied eyeball in a Humongous Mecha to help him. For extra amusement, after t'other god tries to cite its absence in the rules, that there ain't no rule saying you can, the eyeball in its mech comes in and cites the rule in question. Linksky.
According to The Whiteboard, there is no rule forbidding the use of cross-country skis in paintball games. Doc checked very carefully.
Emily wins her first race in Misfile. Ain't no rule against driving 25 mph once you're ahead of your opponent!
Aki Alliance: There's a rule against wearing a headset to receive outside help during a Scrabble competition. Oddly enough, there's no rule against wearing a headset to give outside help to someone else during a Scrabble competition.
Subverted in this strip of Chasing the Sunset where there is a specific rule about knocking out a minotaur and stealing its keys to defeat a magic trial. Because it has already been abused.
In Collar 6 Sixx plans to win her bet with Butterfly by surrendering her title to Laura and becoming her slave so that she can take part in the contest directly.
George: You're a robot! You're not allowed to kill humans! Protoman: That only applies if I think he's a human, which I don't.
Tristan pulls this in Angel Moxie so she can get away with a Non-Uniform Uniform in the form of striped stockings. She even recites the specific rule, noting that while there are limits on what kind of socks can be worn, stockings are allowed as an alternative and there are no such limitations for them.
Take one tabletop-gaming Rules Lawyer from our universe and drop him into an RPG Mechanics Verse with the instructions to "grant our side victory by any means possible". You now have the plot of Erfworld.
Fruit Incest double-subverts this one in "Rule". There's no rule against a duck playing on the school soccer team, but there is a rule that every player on the team must be enrolled as a student. But there's no rule against a duck being enrolled as a student, either.
Another case: Robots are hard-coded to obey and protect humans. When one Jerkass boss fakes a heart attack in order to get to a meeting on time, this response forces them to abandon Florence in freezing water in the middle of a hurricane. With a few tips from Sam, the robots retaliate by "protecting" the boss from things that are bad for him, like coffee, sugar, and stress from meetings.
Sam: "I've never heard maniacal laughter from a robot before. It feels good to have brought something new and wonderful into the world."
uu from Homestuck does this to Calliope (UU) during their chess game by making his king and queen wear hats so UU thinks they're the opposite pieces. As he points out, there's technically no rule against it, and he never had either of them move in a way they shouldn't have... Calliope is, naturally, very unimpressed, and when she plays on only to lose to him she Rage Quits rather impressively.
Immortals in El Goonish Shive are only allowed to guide and empower mortals without risking the wrath of other immortals. Those are the rules, here are the loopholes:
Two unnamed Immortals tricked consent from a younger Susan and Nanase by giving them the false impression that they were the only two who could stop a monster. This ended up causing Susan enormous emotional damage, which later deeply angered another immortal when he learned her story.
Chaos has twisted the rules into pretzels by forcibly empowering unsuspecting mortals and pumping enough power into them to make them susceptible to suggestion bordering on Mind Control.
An immortal can only attack a mortal in self-defense, but according to Jerry doing as little as making a threat (or simply raising one's voice) towards an immortal is enough excuse for them to brutally attack the offender. Jerry even points out that Grace is lucky he's a "wise and jolly" immortal ("Like Santa Claus!"), and it could have gone a lot worse.
Peonio, a power hungry fairy from Fairy Dust, wants to bribe two trolls into staying on his island, where only tiny sized peoples live. When one of them says that he would stay if he had women of the proper size, using his friend as a standard, Peonio brings him women the size of a dragon hatchling that was given the same name as his friend.