This calls for a Secret-Identity Change Trick, and fast. Usually, the superhero will try any excuse and/or use any situation to his advantage in order to change, such as ducking into a telephone booth to swap outfits. On film, such an act allows for an easy way to have the audience understand where and how the hero changes without needing to explicitly show it (Scene X: Civilian enters phone booth. Camera stops rolling, actor leaves booth, changes clothes offstage, re-enters booth, camera re-starts. Scene X.1: Hero leaves phone booth).
- Done oh-so-often in Sailor Moon, but most notoriously in the unusually humorous and self-aware episode 184, where the entire team, as well as the villains, happened to gather in Usagi's house, and she had to run through the rooms looking for a place to transform without revealing her secret identity to the Three Lights. (Who, in turn, had to find a way to transform without revealing theirs.)
- One episode of HeartCatch Pretty Cure! had Tsubomi and Erika unable to sneak off to change when a Desertarian attacks their school. This is made even worse because Itsuki can't join in because she's evacuating the school. It gets to the point where it seems like Tsubomi's ready to forget protocol and either bail there or just transform before Yuri arrives as Cure Moonlight.
- In an issue of Damage Control where Speedball (not Penance) tries to find some satisfactory way to go change into costume when supervillains attack... then tells everyone he's going to go get a frozen yogurt.
- This happens all but constantly when Peter Parker has a secret ID. His running off every time there's trouble generally makes him look like a coward and causes him to miss all kinds of engagements.
- Probably his best excuse came in The Spectacular Spider-Man: "A green guy is holding my boss hostage, and he wants me to come take pictures. Otherwise I might get fired."
- Spectacular also subverted the trope by exposing the lie once (though not the reasons for making it); After Doc Connors becomes the Lizard, Peter makes the lame excuse as usual and everyone assumes he's just freaked out - but the next morning everyone sees Spidey and the Lizard in the paper with the byline "Photos by Peter Parker", making him look uncompassionate and selfish.
- A classic subversion of this came in the issue where a D-list villain attacked Peter in his apartment while Mary Jane was there and he had to shove her into another room while he dealt with said villain. After he runs the guy off and is scrambling for another lame excuse to give MJ about what happened, she admits to Peter that she figured it out a long time ago.
- The two undisputed kings of this trope, Spider-Man and Superman, had an opportunity in the late 1990s to perform this on each other. During the massive Marvel/DC crossover, where characters from either universe get cosmically transported to the opposite universe. IE: Spidey winds up in DC, Robin winds up in Marvel, etc., freelance photographer Peter Parker gets assigned to work with reporter Clark Kent. Naturally, while they're out covering a story, something goes down. Spider-sense goes off, super-hearing picks up trouble. Despite their practice at keeping secrets, they both start an excuse and don't even finish it.
Peter: Oh, I, uh, just remembered...
Clark: Yeah, there's this thing I have to, um...
- In Superman vs. the Amazing Spider-Man, Peter and MJ are taking a stroll on the way to the theater when Peter notices Doctor Octopus' blimp flying overhead. He mumbles "'Scuse me, MJ feeling sick gotta get some water !" before dashing off.
- After his identity as The Flash became secret again, Wally West had to start doing this sort of thing. In one instance, when there's a problem at a social gathering of some sort that he and Linda were attending, he does his standard take-off-so-fast-no-one-sees-it routine, leaving a note in Linda's hand along the lines of "make my usual excuses," thus indicating that (unlike some character's off-the-cuff and often strange excuses for running off) they'd quite possibly discussed and planned for such situations.
- Subverted in the unreleased 1940 Superman story "The K-Metal From Krypton". Circumstances (temporary power loss) trapped Clark Kent, Lois Lane and two thugs in a mine with a dwindling oxygen supply. Unable to easily sneak off to change, Clark simply opened his shirt in front of everyone. The two thugs were said to be too "dazed" to notice what was happening, but Lois was lucid enough to notice and Superman even confirmed to her that she was not hallucinating due to lack of air. Apparently, the plan was to have Lois brought in on Clark's secret permanently, but the idea was vetoed by National Comics (and thus the story was never published).
- One Superman comic indicated that, for his time as Superboy, Clark's father used a long-expired bottle of medicine as an excuse for Clark to go running off.
- Another Superman comic of that vintage (1970s) had Superman having a nightmare about a huge disaster and no way to go and change, with his entire supporting cast bitching at him for his stupid excuses. Especially Lois complaining about his "three hundredth 'Queasy Stomach' routine."
- In Krypton No More, Clark pretends he is sick to push Lois out of his apartment and go to help Supergirl.
Lois: Clark...? Clark, are you all right?
Clark: Oh... as a matter of fact. Lois... I'm not! I've got a splitting headache, a bad stomach, trick knee... Pick any of the above! In a word, I can't have dinner with you So please, go home! I'll explain tomorrow!
- Kryptonite Nevermore provides several examples:
- Clark needs to change clothes during a broadcast, so he sneaks out during a commercial break.
- Shortly after, a rocket takes off, and Superman takes advantage of the noise and the smoke cloud to change clothes.
Superman: The smoke and dust raised by the rocket will hide me from the onlookers... so I can switch clothes without ducking into a phone booth or something!
- In issue #235, Clark leaves Lois' side during a concert, pretending that he's going to get orange juice.
- In DC Comics Presents #9, an ice monster knocks Clark backward through a door that opens to a flight of downward stairs. For him, it is an obvious and perfect opportunity to get out of sight by simply continuing falling and change as soon as he tumbles out of sight down the stairs.
- This happens constantly to the eponymous heroine. After several decades of super-heroing, she has used all kind of tricks and excuses.
- In her first solo book, Kara uses excuses such like "I'm thirsty! I'm going to buy a bottle of water!" or sneaks out of the dormitory when everyone else is watching the TV.
- In her second solo book, Kara takes the train to travel from New York to Chicago◊. Suddenly she decides to head back to the dining car◊.
- In Young Love Linda remembers that she used to come up with all kind of excuses.
Supergirl: Instead, I invented wild ruses to sneak away for work. Richard was so patient with me. But I once left him stranded in an amusement park maze, after having sealed most of the exits. It took an hour before he finally found a way out.
- In Supergirl: Cosmic Adventures in the 8th Grade, Linda takes advantage of an argument between Lena and Belinda to slink away. Later in that issue, Linda pretends she is being dragged away by an invisible/telekinetic super-human.
- Since Bruce Banner is usually not in control of his transformations into the Incredible Hulk, he can't really orchestrate one of these tricks. It's thus pretty convenient for the writers that his secret identity was outed very early in his career.
- In the French Zorro parody Z Comme Don Diego, Don Diego uses the excuse that he's an abject coward who runs away from any trouble even when it doesn't concern him. This backfires on one occasion when he's beaten the problem as Zorro and emerges from his hiding place as Don Diego, but forgot to remove the mask (fortunately, the strip uses Negative Continuity).
- In Robin Tim slips away do deal with some drug dealers with an excuse about grabbing something to eat when he's at a Shakespeare in the park festival for extra credit with some friends. When he takes too long to return and forgets to bring any food back with him his friend Ives covers for him by saying the play is so boring and poorly acted that Tim probably slunk off and took a nap.
- The Secret Return of Alex Mack: Alex's quicksilver form makes costume changes much easier; she can leave her clothes behind when she turns into a puddle, then pull herself into her Terawatt outfit (typically in her gym bag), including a polymer facial coating with makeup already in place. Total time, 15 seconds including wig-straightening.
- The first Christopher Reeve Superman film Superman: The Movie — Clark has to change into Superman, but there seems to be no place to hide to do it. However, Clark finds and runs through a revolving door at superspeed, fast enough to be invisible as he changes clothes and comes out as Superman. This sequence includes a Mythology Gag where Clark first stops and stares at a modern "bubble on a pole" public telephone, in obvious evocation of the older comics and cartoons where he would change in an old-fashioned wooden phone booth.
- This trope gets a Deconstructive Parody in Deadpool: No Good Deed, a short film that plays before the start of Logan. Wade Wilson is walking along the street when he witnesses a mugging; by the time he has finished changing into his costume in a phone booth, the mugger has escaped and the victim is long dead.
- A Downplayed Trope in All Men of Genius, when Violet changes from being "Ashton" to being herself under cover of her Powered Armor-like machine. Her objective isn't actually to conceal her identity, as she wants it to be obvious that its the same person before and after. It's just that making the change dramatic and (from the perspective of observers) sudden works better as a big reveal than just blurting it out.
- In Animorphs, the Animorphs often need to find a hidden spot to morph into animals, or to demorph before the 2-hour time limit is up. They often end up using bathrooms or dressing rooms, but one scene in the first book has all the other kids standing in front of Cassie while she demorphs from horse, to keep a Controller cop from seeing her.
- In The Adventures of Superman episode "The Human Bomb", Clark pretends that he believes the Hostage Situation is a publicity stunt so he can go change.
- In the live-action version of Wonder Woman with Linda Carter, Diana Prince was always running off as if she was scared, only to return as Wonder Woman. Examples include:
- In one episode, terrorists are holding everyone hostage. Everyone is standing there with their hands in the air. Diana Prince (a supposedly highly-trained secret agent of the IADC at this point) takes off running through the crowd. Her actions don't cause panic or get anyone else to flee and the terrorists don't bother shooting her, although they had the ability to do so.
- In another episode, aliens have landed in a field. Steve Trevor, Diana Prince, and a bunch of soldiers are sent out to meet with them. When Diana realizes she could do more as Wonder Woman, she casually walks away only to return to the exact same spot dressed as Wonder Woman. No one realizes that this tall, attractive brunette walked away, changed clothes and returned.
- Despite Diana's cowardice, she never gets in trouble for running away from danger, essentially abandoning her job and endangering civilians at the same time.
- Lois & Clark had fun with this one, and Clark's inability to come up with a good excuse for why he had to leave. The epitome of this being "I have to go pick up my cheese of the month package." Sometimes his parents — and later Lois — would have to cover for him with equally lame excuses.
- This was why David Banner constantly had to walk away from the love interest of the week down a long dirt road to the sounds of sad, sad piano music in The Incredible Hulk (1977). If he'd stayed in one town for more than a few days, eventually he'd transform multiple times and people would realize that David Banner was there every time the Hulk appeared. Also, although David Banner didn't do this part on purpose, he would usually get conveniently shoved out of sight somewhere, leaving everyone to wonder where he went and where the big, green monster came from.
- In the Monty Python's Flying Circus sketch "Bicycle Repairman", the title character uses a ridiculously transparent version of Look Behind You to get everyone to look away so he can change without revealing his secret identity.
- Batwoman (2019). When Catherine Hamilton-Kane reveals that she's known all along her ditzy socialite daughter Mary is secretly running an illegal medical clinic for the underprivileged, Mary gripes over all the outfit changes she did in the elevator to fool her mother. Catherine just adds the elevator had cameras, indicating she found it Actually Pretty Funny.
- In Act I of Dr. Horrible's Sing-Along Blog, this is Played for Laughs by having Dr. Horrible change from street clothes to his supervillain outfit by ducking beneath a concrete wall for about half a second, mid-verse. There's even a tiny sound effect to sell it. The commentary points out that it took Neil Patrick Harris so long to change during filming that they had to play tricks with the lighting to make the scene come out right, and this is just barely visible if you look closely.
- The superhero guide How to Hero has an entry on this.
- In Superman: The Animated Series, Bizarro shows up and begins menacing the Daily Planet offices. Clark kills two birds with one stone by first confronting Bizarro and goading him into throwing him out a window, and then reappearing as Superman, justifying his sudden appearance by explaining that he'd just "rescued" Kent.
- In the superhero episode of Futurama, Bender and Leela quickly find reasons to leave the room when their hero personas are needed. Leela states that she "left [her] apartment on fire," and Bender mentions having to study for the LSAT's. Fry, unable to come up with a good excuse, declares "And I can't take life anymore!" and leaps out the window before promptly leaping back in dressed in his costume.
- In The Adventures of the American Rabbit, Rob Rabbit tells his Jackal captors that he's the tap dancer of the band. They scoff and the senior Jackal demands he dance (over the objections of his partner) and Rob complies. In doing so, he manages to dance out of sight before the Jackals realized he's escape. By the time they turn the corner in pursuit, Rob's already changed into the American Rabbit and tackles them.
- In the He-Man and the Masters of the Universe (1983) episode "The Shadow of Skeletor", Prince Adam changes into He-Man right in front of Teela while she was losing consciousness.
- Jem could project a hologram of either her or Secret Identity of Jerrica, using her earrings, if they both needed to be in the same place, but the hologram wasn't solid. At one point she ran towards the hologram of Jerrica and as they passed close to each other they switched and Jem became the hologram while Jerrica returned to normal. When she needed an off screen switch, usually because somebody asked for the other person, she'd run off with a "Oh there she is, I'll go get her" or have her bandmates run interference.
- In the Batman: The Animated Series episode "The Clock King", Bruce Wayne manages to put on his Batman costume while running up a flight of stairs in a public building... Only the chaos in the street from the villain's sabotage can excuse no-one seeing him.
- In the Batman: The Brave and the Bold episode "Night of the Huntress", Professor Helena Bertinelli is giving Jaime and Paco an orientation tour of the university when they see a news story about a prison break. Helena and Jaime simultaneously declare "I have to go to the bathroom", and head for the restrooms to change.
- In an episode of Underdog, Riff Raff threatens to expose his alter ego Shoeshine Boy if he continues to interfere with his gang's plans. He decides to dart in and out of doors Scooby-Dooby Doors-style to flummox him before defeating the gang.