The movie of has Yoriko do this to her skirt during a hostage situation so she can move better.
Natsumi also did it once in the TV series, when she needed to find a hidden bomb... placed in a huge clock.
In the Ghost in the Shell: Stand Alone Complex episode "Meme", Major Kusanagi is in her skirted (and rather tightly) military uniform when a situation arises. She tears it herself so she can run in it.
Project A-Ko: This happens to A-Ko's skirt by the end. Not by her choice, though. It was cut by a sword during her fight with D.
Happens to Euphemia in Code Geasswhen she begins her Geass-induced massacre.
In episode 5 of Kiddy Grade, "Day / Off", Eclair's Super Strength suddenly activates while at a fancy restaurant with a friend. She accidentally starts a fight, in which her dress is torn immediately. "Aw, and this was a new one!"
In the first season of Slayers, Lina and co. has to disguise themselves to sneak onto a ship to where the Big Bad was waiting. Along the way, they bump into a dragon. So, she does this just before fighting. Since this was episode 17, Gourry has to do this as well.
Azaka does this in the 6th Kara no Kyoukai movie, since her school uniform is essentially a nun's habit and pretty restrictive.
Done by Galatea in Claymore in the fight against Clarice and Miata (chapter 74).
One Piece: In the Alabasta Arc, Nami tears the skirt of her Dancing Girl Outfit in order to fight better against the assassin Ms. Doublefinger.
In the last few episodes of Pumpkin Scissors, Alice goes to a fancy ball with her fiancé, Lionel. She dresses up very nicely for the event, but when a mob shows up, intending to kill a certain philandering Lord and the other guests too, she challenges that Lord to a duel to keep the bloodshed to a minimum. He calls forth two assassins as proxies instead of fighting her himself. After fighting for a while in her fancy dress and heels, the hem of her skirt is cut/torn by her opponent, and she pauses long enough to tear it shorter and more even, so as not to trip on the ragged end.
Charlotte does this during the Griffith Rescue Mission arc in Berserk.
Uncanny X-Men #98: Jean Grey is in an elaborate ankle-length evening dress, not designed for running from Sentinels as they are doing. When Jean tries and fails to tear the dress, Logan volunteers and rips a substantial chunk off, leaving Jean to do battle in a raggedmicro-miniskirt.◊
Jean:Hey! Not so blasted short!
Another X-Men story subverted this: When the Fury starts to attack the X-Men, Logan points out that Storm's dress isn't really suitable for fighting in, and makes the appropriate adjustments with his claws with just as much glee as before. Storm looked rather annoyed, and then switched off the holographic image inducer she was wearing, revealing that she was actually wearing trousers, which are now shorts.
Lady S once has to climb on the roof, and she wears an impractical dress. So she could have used this trope. But she subverts it by removing the dress instead, proving she's a Shameless Fanservice Girl.
Being Genre Savvy, Modesty Blaise has invested in a skirt with Velcro instead of stitches on one side so it can be removed quickly. If she happens to be wearing something else when the mooks of the day surround her and ask her to step into their car, she'll do an Action Dress Rip and (sometimes) complain that she just bought it later. Modesty Blaise ditches both her skirt and her high heels before the fight in several episodes. She could have named this trope... except that, as noted, she typically removes the skirt entirely rather than just rip it open.
A variation/aversion/deconstruction: In the notorious Ranma ˝Fan FicGirl Days, the characters find a store which specializes in Fighting Skirts: skirts which, thanks to conveniently placed fabric fasteners and snaps, can open on the sides and give the wearer more freedom of movement without having to rip the clothing. The discovery leads to the following exchange:
Ranma: What the heck gave anyone an idea like that? Clerk: Miss — this is Nerima. Ranma: Good point.
In the Mobile Suit Gundam Wing doujin OZ, the cast enters a virtual reality game which, due to a programming bug, is putting every newcomer in Relena's body briefly before giving them a new role. When Wu Fei shows up, he rips Relena's school uniform skirt for mobility. Heero chews him out, saying that Relena wouldn't do that even in a fantasy world and that he won't allow it. This strong reaction is what clues Wu Fei into Heero's feelings for Relena.
According to this artist, Peach got tired of waiting for Mario to rescue her and decided to finish things once and for all.
A variation occurs in Licence to Kill, where Pam's evening gown zips off at the knee.
The same variation occurs in the first Charlie's Angels film, where Dylan strips off the bottom half of her ballgown to reveal more action-friendly leather pants.
Occurs in Sky Captain and the World of Tomorrow before Polly starts running away from the robots attacking New York City. She carefully rips the side hems of her longish, straight skirt — but leaves on the heels.
Teenage Mutant Ninja Turtles III: After switching places during time travel, April O' Neil wears Kenshin's samurai outfit in feudal Japan. Later, after escaping from the dungeon with the Turtles, we see her ripping part of the samurai clothing off by the lake while Leo and Donatello are looking.
In The Lone Ranger, Rebecca tears the bottom off her dress before crawling along the outside of the train.
Jane in Austenland has been riding sidesaddle, but needs to ride astride to outrun a rainstorm. In this case the dress is ripped vertically. (She still has some kind of long underwear to conceal her legs.)
In Machete Kills, Miss San Antonio slices a long line down her skirt so she can move freely.
There's a scene in By the Sword by Mercedes Lackey where Kero tells her brother's betrothed (whom she had just rescued from a wizard and a large creature she was going to be fed to) to slit her skirts so she need not ride sidesaddle. The latter was horrified about the prospect of being so "unwomanly" until Kero made an observation:
"That leech-thing might not be dead, you know."
Defied in the Arrows trilogy, where Queen's Own Companion Talia (who might have to conduct a ceremony one minute and defend the Queen at knifepoint the next), has a formal gown which is specifically made to be practical to fight in — no train, for example, and detachable sleeves.
In Andre Norton's ''Ice Crown', the kidnapped Princess Ludorica borrows the heroine's knife, and calmly and pragmatically slash-tailors her long nightgown into a serviceable coverall (she not only slits it, she cuts strips to bind the fabric to her legs) so she can move more easily while they escape from the Mooks guarding her.
In Phillip Reeve's Larklight, Ulla doesn't stop at ripping off the hem — she rips the entire skirt off. However, the book being a Steam Punk fantasy, she's still wearing knee-length underwear.
Averted in a Tortall short story where Kylaia has to challenge a man to win back her sister's honor. Rather than rip the dress, she just takes it off and fights in her underwear.
Creel of Dragon Slippers is forced to rip her heavily embroidered dress (a showcase of her talent in order to get a sponsor) in order to ride dragon back, and thus save the kingdom. she is able to save most of it, though, by simply slitting the sides.
However, in Dragon Spear, Creel is forced to utterly destroy her wedding dress in order to save Veilkca's eggs from falling into the sea this time it doesn't get better.
In Breaking Dawn, newborn vampire Bella goes out for her first hunt in a tight evening dress that Alice put her in. As she gets ready to jump the river, the dress rips. Bella then rips both sides in order to get the mobility needed to run, much to Alice's chagrin. Prior to this moment, she had ditched the high heels.
In the first book of Mistborn: The Original Trilogy, Vin rips away the entire dress when in a hurry. Later she gets a dress designed for Mistborn who wish to avoid doing this and loves it.
In an episode which has Xena and Gabrielle reincarnated in the modern day, the reincarnated Xena does this, signaling the moment that she's stepping into her previous incarnation's shoes and is about to kick serious ass.
She also did this in Season 1 episode "Chariots of War".
She does this any time she has to dress nice, like the time she and her princess lookalike have to "Freaky Friday" Flip because princess lookalike is being hunted by assassins.
Naomi in Metal Gear Solid 4: Guns of the Patriots. In order to run from incoming Gekko, she rips her stockings and gets rid of her shoes in other to move faster. Other than being somewhat sexier (she wasn't wearing a bra, in the first place, and left her lab coat unbuttoned. Plus if you got a stocking foot fetish well...), it doesn't have anything to do with the plot.
This happened in Tomb Raider Legend when Lara Croft visited Japan in a very fetchingLittle Black Dress. The Yakuza showed up, and Lara dove for cover behind the bar and strategically ripped her skirt before coming up with guns in both fists to return the favor.
Unfortunately averted in the "Dreamcatcher" module for Neverwinter Nights, in which your Love Interest (be she Anera or Teira) will trot ahead back to your bedroom to change before going into action.
Joanna Dark in Perfect Dark, when a reception at the Carrington Institute has some unwelcome visitors.
Calista does so in The Last Story when the Gurak attack Lazulis Castle during her engagement announcement. Though five minutes later, you pass by her room and she can duck in to change into something more appropriate.
You also get to keep the torn dress as a piece of armor exclusive to Calista. It had apalling stats and can't be upgraded, but keeps is fanservice appeal and can even be dyed different colors!
Officer Hipbone in Girly doesn't destroy her dress, but when a below-the-knee hem rises way above the knee, she thanks the attacker and does a ludicrously high kick to destroy him.
Done by Irene Adler in Mayonaka Densha when the lights go out in the museum, while chasing a criminal. Subverted by Jessica Queen who manages to kick some ass and keep her dress intact.
Averted in Sluggy Freelance when Torg and Gwynn, out on a pseudo-date, have to run when the cops show up. Gwynn responds, "Like I'm going to run in this dress." She then proceeds to slowly shuffle away.
In the first and only canonical episode of the third season of Gargoyles, Elisa is dressing up for Goliath when the Quarrymen jumps in and ruins their date, forcing them to flee across rooftops. When Goliath takes a wing injury, Elisa tears part of the hem of her dress to use as a bandage, making the skirt of the dress visibly shorter. She also kicks off her high heels, since from this point on their escape isn't going to involve gliding.
Samurai Jack Episode XXIX "The Good, the Bad, and the Beautiful": Josephine tears off the hem of her Gorgeous Period Dress to not only better attack Jack, but also to access the two six shooters she had holstered to her bloomers.
Adventure Time: The Gender Flip episode "Adventure Time with Fionna and Cake" features Action Girl Fionna attending the ball in a Pimped-Out Dress, only to need to rescue Prince Gumball. Fortunately Ice Queen's attack tears the hem of her dress so that she can jump to the retractable sword in her purse.