It's Been Done

""I have this great idea for a new novel. It's about a little girl from the midwest who gets swept away by a tornado into a Magical Land of whimsy and wonder. There, she makes friends with a wild beast, an automaton, and an animated doll. Together, they travel to a city of jewels and fight an evil witch to get her home. Wait, what do you mean it's been done before?""

A lengthy joke in which a character describes some new idea, invention, story or script—but is informed that somebody already got there before him, and that all the tropes he thinks are new are Older Than They Think. The punchline is usually a ridiculously mundane or roundabout name for the proposed "new" work, and for added humour value, the story that the character has unknowingly plagiarized is usually something mind-bogglingly well known.

It's based on the well-known phenomenon that there are so many things out there it's incredibly hard to come up with something new, especially since Seinfeld Is Unfunny and oftentimes, people get the idea inspired by something. (Even the great JRR Tolkien's stories were inspired by pulp fantasy writers in the 1930s and borrow heavily from Germanic myths about a ring of massive power to who wears it... sound familiar?)

There are many other ways of phrasing this, including:
 * From a 19th Century BCE Egyptian poem: "What has been said has been said."
 * From The Bible (Ecclesiasties 1:9): "It has all been done before; there is nothing new under the sun."

The surest way to avert this trope is to put enough old things together that the ensuing Combinatorial Explosion results in something new or unexpected.

Compare It Will Never Catch On and We Have Those, Too. The Zeroth Law of Trope Examples explains how Shakespeare did it before. For how the hearts of budding artists may be quickly crushed, see Tropes Will Ruin Your Life.

Not to be confused with the Barenaked Ladies' song about serial reincarnation.

Anime & Manga

 * In Yakitate!! Japan, several types of "Ja-pan" that Kazuma developed on his own turn out to be just variants on well-known types of bread. For example, Ja-pan Number 34 is basically a croissant, and Ja-pan Number 16 is a naan (an unleavened Indian bread often served with curry) bread bowl in the shape of Mount Fuji.
 * In Bleach, Soifon reveals while fighting Yoruichi that she has been developing a new kido that combines kido with unarmed combat, saying that she hasn't even named it yet. When she demonstrates the attack against Yoruichi, Yoruichi reveals that it already has a name and counters with the completed version of the attack. Yoruichi then goes on to explain how the attack affected the uniform design for Soifon's position, which Yoruichi previously had. Because it destroys clothing over the back of the user, the uniform is backless and shoulderless.

Comics
"Snapper: There's nothing new under the sun. The only recent new idea was casting Danny DeVito and Arnold Schwarzenegger as identical twins. Before that you've got to go back to the Magna Carta."
 * A Bloom County strip parodied this in which a teacher claims there no new ideas in the universe. A student argues the point, but is told that "Failure is hardly original."
 * Gyro Gearloose from the Donald Duck comics has a tendency to invent things which already exist. In one comic he is asked to repair a suitcase with 4 wheels, of which one is broken. He keeps adding improvements, such as a seat, a steering wheel, bigger wheels and so on, and proudly delivers it back to the owner, only to be told "We already own a trailer!" In another comic, he goes picnicking, but is bothered by various elements like ants, the wind and rain, causing him to create a floor, walls and a roof. In the end, he's re-invented the house, and wonders why he didn't just stay home. In another comic, Gyro is found in the woods studying woodpeckers so he can make a "machine that can make holes like them." In other words, a drill.
 * In Don Rosa's story "Mythical Menagerie", Donald Duck tries to pull a prank on Huey, Dewey, and Louie, who are going animal-spotting for a Junior Woodchucks merit badge, by gluing props onto farm animals to make made-up creatures... unfortunately, all the creatures Donald makes up are unwittingly based on creatures from mythology: A yellow rabbit with a horn? A mi'raj from India. A polka-dot cat? A gulon from Scandinavia, and so on.
 * UK newspaper strip The Perishers had Marlon, the keen but not-very-bright kid, who on one occasion took up inventing for a hobby. When his friends pointed out that his inventions (fire, the wheel and the horse and cart) had all been invented by other people, he wasn't worried because he invented them quicker and was therefore catching up.
 * Used in a French comic parodying the superheroes genre, Man! The title character, wishing to become a superhero, tries to convince his parents of this career choice. When it comes to select a name and costume, he first chooses a bat-themed one and the name "Bat-Man"! But his parents tell him "It's been done already." Frustrated, the hero then chooses to be "Super-Man"!... and a bunch of lawyers appears out of nowhere, explaining how much trouble he's in. Fed up with American-style heroes, the protagonist then decides to aim for something more specifically French... "Superdupont-Man"! Only to have Marcel Gotlieb's avatar showing up and tsk-tsking.
 * Snapper Carr in Young Justice put it nicely.


 * In a Dilbert strip, Dilbert was presenting his idea for a way to use electricity to cook your food "Without the need for charcoal or lighter fluid" to Dogbert, and announced he would name it the X-39 Energy Transfer Module. Dogbert simply replies "Did the name 'Electric Stove' ever occur to you?", pointing out Dilbert's invention fell back on this trope.

Fan Works
"Gauntlet: Okay, we build a monorail so our city's citizens can get around quicker! Robin: Simpsons already did it. Gauntlet: DRAT! Okay, we take advantage of certain strange government wounded egos to get one of our own sent into space! Beast Boy: ... dude, we go into space all the time. Terra: We went into space last week because you wanted legit Vietnamese food and wanted it yesterday. Robin: And Simpsons already did it. Gauntlet: ... drat. Okay... aha, we assume a superheroic identity and battle evil doers by throwing pies in their faces! Terra: ... Rob we already have superheroic identities. Starfire: And how would throwing pies in the faces of our foes do anything? It strikes me as ineffective. Beast Boy: Our methods work just fine! Terra: We don't need to change them! Cyborg: It's in our union contract! And I'm no good at making pastries! Robin: And Simpsons already did it. Gauntlet: Fine. We take over the world and rule it via a complex conspiracy! Robin: Illuminati already did it. They don't like competition."
 * Titan Legends, a Fanfic that is a universe unto itself, actually uses the line "The Simpsons did it" in the following exchange where Gauntlet tries to find something to do:


 * One spinoff short story to You Got Haruhi Rolled has Kyouko telling Fujiwara about the plot of a fanfic she is writing, about a Living Toy who learns, to his horror, that he is just a CHILD'S PLAYTHING! Fujiwara then says that this is the exact plot of Toy Story.

Films -- Animation

 * The Italian film Allegro Non Troppo begins with the director explaining his concept to the audience: a collection of animated shorts set to pieces of classical music, "a Fantasia, if you will." Then he gets a call saying that it had already been done by someone named "Prizni".
 * At the end of the film, he goes on explaining his idea for a new film, a romance of some sort between a beautiful woman and not one or two, but SEVEN little men.

Films -- Live-Action
"Dr. Evil: Right, people you have to tell me these things, okay? I've been frozen for thirty years, okay? Throw me a frickin' bone here!"
 * Austin Powers has Dr. Evil suggesting schemes that include events that happened while he was in a Human Popsicle, such as creating a hole in the ozone layer over Antarctica and blackmailing the British Royal Family with false evidence that the Prince of Wales had had an affair.

"Dr. Evil: Let's just do what we always do, hijack some nuclear weapons and hold the world hostage, yeah?"
 * Luckily, he has a backup plan:

"Reuben: This guy actually tasted fresh oxygen before they grabbed him. Of course, he was breathing out of a hose for the next three weeks. Goddamn hippy."
 * Done again in the second film, where Dr. Evil travels back in time, formulating plans based on the same media he was ignorant of while still frozen. These include ideas like his "Death Star" laser on the moon, and even using footage from Independence Day to threaten the President.
 * Donald's script in Adaptation is this in about fifteen different ways.
 * A variant in Ocean's Eleven, as Danny and Rusty pitch the central heist: "It's never been tried." Reuben gets a wonderful recap of the top three attempts, each illustrated with a period-piece flashback and his own sarcastic commentary.


 * The plot of Secret Window revolves around a man threatening Mort for stealing his story, only to find out that Mort published his story a full two years before he claimed to have written it.

Literature
"Sifting through all my words For what has been said is just repetition What has been said has been said."
 * Possibly the Trope Namer,in the Book of Ecclesiastes (1:9), its heavily cynical author complains: "What has been will be again, what has been done will be done again; there is nothing new under the sun."
 * Older Than Dirt: Quoted from a 19th Century BCE Egyptian poem. (Translation credit to Guy Deutscher):

"Genius: Isn't there a clerk who can examine patents? Boy: Quite unnecessary, Sir. Everything that can be invented has been invented."
 * From an 1899 issue of Punch, projecting into the next century (20th century):

"If with the literate I am Impelled to try an epigram, I never seek to take the credit; We all assume that Oscar said it."
 * Terry Pratchett's The Dark Side of the Sun has a dream sequence in which a character explains the course of various potential plots for the story, all of them are the plots of classic SF/fantasy novels (Dune and The Lord of the Rings are included). The main character dismisses them all as implausible, telling the other "Try the reality next door", suggesting that these events are taking place in one of the many parallel universes hinted at in the novel.
 * In the Discworld novel Wyrd Sisters, there is a dwarf playwright who swears his ideas come from literal bolts of inspiration from other universes, resulting in his plays showing influences from The Importance of Being Earnest, Duck Soup, Laurel and Hardy, The Three Stooges, and Charlie Chaplin's "Little Tramp" character. They frustrate him because he knows they should be funny, but can't understand why or how to make the audience get it.
 * Pratchett reused the joke with movies in Moving Pictures and with Opera and musical theater in Maskerade.
 * And then there is the in-universe version in Monstrous Regiment, with Lt. Blouse devising a vast number of foodstuffs in the hope of getting one named after himself... only to learn that each and every one of them already existed.
 * And in Soul Music there is a thief who attempts to steal the secret of fire from the Gods, only to be informed by everyone that they've already got it.
 * One SJ Perelman story has a character describe his idea for a detective in Victorian London whose adventures are documented by his former Army doctor friend.
 * Dorothy Parker had this to say about Oscar Wilde:

""And is it not possible that, by obtaining genetic material from fossils, scientists could clone NEW dinosaurs?" "OBJECTION!" thundered the district attorney. "He's introducing the plot from the blockbuster science thriller and motion picture Jurassic Park!""
 * In John Hodgman's More Information Than You Require, J.D. Salinger comes out of retirement with a new manuscript for a Catcher in the Rye sequel, in which Holden Caulfield "discovers he has magical powers. He goes to a special school for magicians, which he finds (predictably) unbearable. Ditching school once again, he finally discovers his true destiny: to do battle with an ancient evil wizard named 'Phony'." Salinger is then sent a copy of the first Harry Potter book in the mail, and burns his manuscript.
 * In the Dave Barry column "Courtroom Confessions", this occurs as a Courtroom Antic:


 * Sherlock Holmes, in his early novels, claimed that part of his investigative talent lies in his comprehensive study of the records of earlier crimes.

Live-Action TV
"Gilligan: Why don't you call it the Frisbee? Professor: Why? Gilligan: Because that's what it's called."
 * In 3rd Rock from the Sun, a professor being forced into retirement takes solace in the fact that he'll have time to finish his screenplay. "It's like Die Hard, only set in an office building."
 * Played with in another episode, when Tommy needs to write a paper on his family history. He has forgotten to create this little detail, and his on-the-spot attempt is taken directly from The Sound of Music. When his girlfriend points this out, he responds, "Yeah, and don't think we're not suing!"
 * In Frasier, Roz sells an idea for a children's book based on a bedstory that her mother used to tell her—which turns out to be Heidi. Furthermore, not only had she not heard of it, but the publisher to whom she sold the idea hadn't heard of it either.
 * Played with in episode "200" of Stargate SG-1: Vala tries to pitch her "adventures" to a visiting Martin Lloyd, except she's deliberately ripping off well-known plots like The Wizard of Oz or Gilligan's Island.
 * This culminates in a ripoff of Farscape, Claudia Black's previous show, which Martin admits he doesn't recognize.
 * In Rescue from Gilligan's Island, the castaways try to reclaim their lives away from the island, and all of them have trouble doing so. The Professor's problem is that all the things he invents (such as the electric toothbrush) have been invented during the years he was gone.

"Alien: Oh! What if I were to hollow out the Earth's core, and replace it with a giant motor, so that I could pilot it anywhere in-- Doctor: It's been done. Alien: Are you sure? Doctor: Yep. Alien: Oh. Well, you're the expert..."
 * There was an episode of Saved by the Bell where a character describes his new invention in detail only to be told he's just invented the pencil.
 * Kelso from That '70s Show once came up with the brilliant ideas for adult strollers (wheelchairs), bicycles with engines (motorcycles) and bicycles without engines (take a guess...).
 * Similarly, in one episode of Becker, Jake and Bob (while drunk) come up with various inventions which, of course, have already been thought of, such as an iron and a VCR. Interestingly, all of their ideas involve getting "a flat piece of metal".
 * Lampshaded on Mystery Science Theater 3000 during an invention exchange, in which Joel presents the Steve-O-Meter, a device which detects whether a given idea or object has already been thought up by Steve Allen. It turns out that everything Joel and the 'Bots present has been already imagined by Steve, including the Steve-O-Meter itself.
 * In another one Frank invents the staircase and the rowboat as exercise devices.
 * An episode of Blossom featured the title character trying desperately to write a song, only to be repeatedly informed by other characters that they were unconsciously plagiarizing various existing songs.
 * An interesting example occurred in Will and Grace. Karen would go into a story about her life, which would be a famous story (some that she mentioned were Norma Rae, Heidi and Speed). Although, Karen was always heavily medicated, so she might have actually thought they were her life stories.
 * Particularly during the Tom Baker era, the Doctor often seems unimpressed by predictable attempts to rule the Earth and/or the universe. A Doctor Who parody by Mark Gatiss and David Walliams involved the villains wanting to be thwarted by the Doctor, but having the bemused Doctor inform him that his plans had been done already.

"Executive: He brought me a script about a white kid who could do martial arts. I said I liked it better the first time, when it was called The Karate Kid! Grandson: It was The Matrix. We passed on The Matrix."
 * Aliens really did try to steal Earth that way, in The Dalek Invasion of Earth. The Doctor briefly mentions this in "The Stolen Earth" when he says that, "Someone tried to move the Earth once before."
 * In an episode of Seinfeld, Elaine despises a cartoon in The New Yorker so much that she submits her own idea. When her boss sees her published cartoon, he soon identifies the punchline as "a Ziggy", stolen from the newspaper comic of the same name.
 * Malcolm in the Middle: Malcolm tries to prove his hand at music by writing a song. Dewey points out that he just added emo words to the "Meow Mix" jingle.
 * Homer's done that as well. Which means... ya know...
 * Reese once proudly announced, "Guys, I've made a discovery! I mixed blue and yellow, and got a whole new color! I'm going to call it... 'Blellow'!"
 * Tenacious D: Jack Black comes up with a killer tune for his song 'Rocket Sauce' ("Rocket... Rocket, all of my Rocket Sauce") then hears a familiar ice cream van jingle through the window...
 * One episode of Good Eats had Alton Brown announcing he'd be testing food urban legends, and he was going to call the episodes "Food Myth Busters"... whereupon his lawyers burst in and inform him that it's taken. He amends it to "Food Myth Smashers".
 * Played with as a Running Gag on The Mitchell and Webb Situation, in which a pair of contemporary writers would swap ideas about a project which would be obviously recognizable as an already existent product, from Fairy Tales, to The Bible, and even the Great Wonders of the World. Once the recognizable element appeared ("the story's not about the wolf -- it's about the pigs..."), they wouldn't be corrected as to the nature of their idea but would eagerly start typing, implying that they were actually the originators of the idea in the first place.
 * Inverted in a recurring sketch on Saturday Night Live, where a film studio executive would berate his grandson for wanting to buy scripts that had obviously "been done before." The catch was that the scripts he ended up passing on were, in fact, highly original future blockbusters.
 * One example:

"Executive: He wanted to back a film about a bunch of little people living in a magical land. I said I liked it better the first time, when it was called The Smurfs! Grandson: It was Lord of the Rings. We turned down Lord of the Rings."
 * And another:

""Tell me this, does the North win, or does the South?" "Why, the North." "There, how do you like that, he took my ending!""
 * Also played straight in a sketch where Satan tries to convince a young musician to sell his soul for a tune... but can't, because he can't think of anything good or original to trade for it. He even forgets, for a moment, that Smash Mouth has already done one of the tunes he tries to fob off on the guy.
 * Monty Python's Flying Circus featured Mr L F Dibley who moaned about the critics who said his films (including If, Midnight Cowboy, 2001: A Space Odyssey and Rear Window) were just cheap rip offs of better directors' films. He insisted that he came up with the ideas first, but the more high-profile and high-budget versions were "rushed out" whilst he was at the chemist getting his developed.
 * In an episode of Northern Exposure, Chris intends to catapult a cow as some sort of performance art until Ed tells him that it was already done in Monty Python and the Holy Grail.
 * Jon Stewart decided he was going to sign off The Daily Show with his own brand new catch phrase "Keep f*cking [sic] that chicken" before revealing It's Been Done... live... on the news... unironically.
 * Keep Fucking That Chicken
 * In the 30 Rock episode "Into the Crevasse", Jack and a bunch of the TGS writers attempt to create a revolutionary design for a microwave, but end up re-inventing the Pontiac Aztek.
 * Sid Caesar once played a famous German director, who gave his brilliant idea for a film, which turned out to be Gone with the Wind. Right down to having the same title.

"Angelus: Doing your Mom... and trying to kill your Dad. There should be a play."
 * On The Late Show, Amy Sedaris talked about an idea for a movie involving a fat, grumpy ginger cat who would solve crimes. David Letterman commented that the character sounded similar to Garfield. Sedaris was disappointed and said that always happens to her, and recounted a story of the time she was watching Godzilla and suggested to her friend that it would be scarier to have tiny creatures terrorizing humans for a change instead of huge monsters. Friend: "Oh, like Gremlins." "Oh, well then forget it."
 * In an episode of Full House, Jesse tries to write a song for his band, only to come up with such songs as "This Land is Your Land" and the theme to The Brady Bunch.
 * In another episode, Jesse "invents" a face guard for spraying hairspray without getting it in your eyes. He then gets sued by the original creator.
 * The B Plot of the Cheers episode "Young Dr. Weinstein" has Woody fall victim to this, then try to subvert it. His goal is to create a unique drink to get into the Bartending Hall Of Fame. He eventually succeeds, but can't remember what he put into it.
 * Done in one episode of Angel.

"Reid: First of all, it's a police box, not a phone booth. Second of all, Doctor Who started a quarter of a century before Bill and Ted even went on their bodacious adventure, so really they should have called it Bill & Ted's Excellent Ripoff."
 * In one episode of Clarissa Explains It All, Clarissa attempts to create a new musical composition only to be told each attempt that if she slowed/sped up the melody she'd have an already written song.
 * In Criminal Minds, Reid asserts that Bill and Ted's Excellent Adventure is a ripoff of Doctor Who.

Puppet Shows
"Stormy night, not even a star in sight, On my way to where the sky is dark, Can you tell me how to get, how to get to Yellowstone Park?"
 * The Sesame Street skits in which Don Music slowly and painstakingly tries to compose songs that already exist. He usually gets one word wrong, and then has to change the rest to fit, as in:


 * Sesame Street has a scientist character named Dr. Nobel Price, who keeps inventing things that had already been invented. Some of his most notable creations include foot-snuggies (socks) and the speaking stick (a microphone), and he discovers an animal that he calls the Great Poonga-Poonga (which turns out to be a rabbit).
 * Unfortunately, Dr. Price didn't invent body-snuggies so we wouldn't have to deal with those direct response ads.
 * Between the Lions has a scientist character named Dr. Nitwhit who announces that he's discovered "the only word in the English Language that X" (has the same consonant at the beginning and the end, is spelled with a given sound). When his assistant responds, it's always with words that just happen to prove that the rule is more general than poor Nitwhit thought.

Radio

 * During one Big Finish Doctor Who audio drama, The Wormery, the Sixth Doctor (post "Trial of a Time Lord"), runs into Time Lady Iris Wildthyme. The plot culminates with the revelation that the villain is basically her version of, and throughout the entire ending the Doctor complains to both of them just how amazingly unoriginal they're both being, outraged by the plagiarized dialogue and recycled scenario.
 * This is something of a habit for Iris, as many of her adventures bear a striking resemblance to the Doctor's (or possibly vice versa).

Theater

 * In Rent, Roger's attempts at writing the perfect song all end up sounding like Puccini's "Musetta's Waltz" (which is to say, "Quando m'en vo" from La Bohème, on which Rent is based.)
 * In Norm Foster's play Office Hours, one character unintentionally pitches an idea identical to Tarzan.

Video Games
""So, I have this idea for a great movie. It's about two gnomes who find a bracelet of power, and they have to take it to the Burning Steppes and cast it into the Cauldron. They form the Brotherhood of the Bracelet. Along the way they're trailed by a murloc named Gottom, who's obsessed with the bracelet, and nine bracelet bogeymen. It could be a three-parter, called Ruler of the Bracelet. The first part would be called The Brotherhood of the Bracelet, followed by A Couple of Towers, with the climactic ending called Hey, the King's Back!""
 * One of the human male/silly options in World of Warcraft is one of these for The Lord of the Rings:

Web Animation

 * The web cartoon Kerri's Big Invention: At one point Kerrigan comes up with an idea for an invention called "Stick'ems" that turns out to be identical to Post-It notes. One other character points out that she even put notes about this new idea on Post-It notes.
 * Retarded Animal Babies has apparently been accused of ripping off Happy Tree Friends, simply because they both feature cute animals and sometimes gory violence. The creator responded to these claims with a Take That in the second episode.

Web Comics

 * Although the example isn't "lengthy", Freefall ran afoul of this, inadvertently repeating a joke from another webcomic.
 * Greg Dean, the author of Real Life Comics, issued an apology after learning that his previous joke had already been done by Dilbert.
 * Another strip has the lead ask his Mad Scientist friend to make him a web-shooter after seeing Spider-Man, only for said friend to demur because FoxTrot had already done it.
 * The second page of How to Make a Sprite Comic in 8 Easy Bits has its protagonist think up a few different ideas for his magnum opus—first a Final Fantasy parody, then a Mega Man comic...
 * The author of The Dragon Doctors once explained that he originally had another comic in mind, but it turned out El Goonish Shive had done the whole concept first.
 * Irregular Webcomic. Here, Ishmael considers using time travel to kill Hitler and prevent WWII. Loren replies, "Do you realise that question or variants thereof has been asked so many times that there are no original or funny answers left?"
 * This Bob and George strip is, in the words of the author, "a joke about reusing jokes about reusing jokes. Very postmodern."
 * According to Scott Kurtz, Penny Arcade is a major cause of this trope.
 * In this Questionable Content, Faye snarks on one of Raven's costume ideas by comparing it at great length to Hooters. At no point does Raven notice what she's doing.
 * In this Men in Hats strip, Aram decides to keep Beriah from talking to him by demanding he fill out an application first. Beriah says that he saw this done in a cartoon, which makes Aram reconsider—but he still won't let Beriah talk to him, just because.

Web Original

 * One Zero Punctuation review of a Zelda game has Yahtzee suggesting, "for variety", an adventure game where you play as a dog in feudal Japan.
 * A YouTube Poop video titled "The FCC Shuts Down Rock TV" contains a parody of the Super Mario World cartoon featuring an episode with a Flash Back that cut to a flashback of another episode. The author then apologized, saying he realized another video called "Youtube Poop: the true power of Rock TV" used the exact same joke.
 * Doug Walker said in commentary he was disappointed to find out that subverting the It's a Wonderful Plot trope had been done numerous times before (such as The Fairly OddParents and Johnny Bravo).
 * Ask That Guy subverted this trope by suggesting an original movie: 2½ hours of exploding babies.
 * Though he also says that as far as he can tell, it's still the only take on It's a Wonderful Plot in which the guardian angel takes a look at what his own life would be like without the protagonist.
 * The year the television shows The Singing Bee and Don't Forget The Lyrics came out, Rhett and Link did a sketch where they played two producers pitching the shows at the same time.
 * In her Month of Miyazaki review of Nausicaa of the Valley of the Wind, JesuOtaku wishes that Miyazaki would the movie and redo it really well, "give the heroes more human traits and motives, give the villains more human traits and motives, portray nature - even a fantasy vision of nature - in a more honest light, and then wrap it all up in more conversational dialogue." While thinking of how awesome this hypothetical movie would be, she remembers Princess Mononoke exists.

Western Animation
"Cartman: Dude, The Simpsons have done everything already. Who cares? Stan: Yeah, and they've been on the air for like, thirteen years. Of course they've done everything. Mr. Garrison: Every idea's been done, Butters, even before The Simpsons. Chef: Yeah. In fact, that episode was a rip-off of a Twilight Zone episode."
 * The South Park episode "Simpsons Already Did It", in which Butters—or, rather, Professor Chaos—attempts to come up with an idea to get revenge on the citizens of the town. However, he's informed that The Simpsons had already used every one of his ideas in an episode, and his desperation to come up with an original scheme briefly drives him over the edge.
 * According to the DVD commentary, this is pretty much how creators Trey Parker and Matt Stone (themselves fans of The Simpsons, despite having only ever seen a few episodes due to their busy schedules) feel on coming up with a great idea or joke only to find out that it was done by The Simpsons. ("There are days when I curse The Simpsons out the door.")
 * The DVD commentary for that episode also revealed that Parker and Stone realized too late that the episode's other plot, involving a microscopic society of sea monkeys, had also already been done by The Simpsons. They went on to have Butters Lampshade Hanging the fact (since he beforehand had seen all one hundred and thirty-two episodes of the show. Twice). Everybody's reaction (after a long Beat)?

"Homer: The Simpsons are getting a horse! Comic Book Guy: I believe the Simpsons already had a horse, forcing Homer to take a second job at the Kwik-E-Mart, with hilarious results. Homer: Does anyone care what this guy says? Crowd: (in unison) NO!"
 * An interesting note that The Simpsons successor Futurama already did it in an episode "Godfellas" aired just months prior to South Park when Bender is drifting in outer space which microscopic space aliens settled on him and becomes God (Bender's back side being ignored). Both sides end up nuking each other.
 * Done again in the Halloween episode Hell on Earth 2006 where Satan's attempts at a shocking 16th birthday party entrance are rejected when his minions repeatedly tell him "Diddy did it."
 * "God damn it! What didn't Diddy do?!" -Satan
 * The Simpsons itself did this one of the most explicit, memorable versions of this joke as well, having Seymour Skinner come up with a story about an island theme park that clones dinosaurs back to life. His name for it? "Billy and the Cloneasaurus". He is then immediately lambasted by a furious Apu, who spends several minutes pointing out the ludicrousness of the principal not knowing about a billion dollar franchise consisting of bestseller books, games, comic books, and "one of the most popular movies of all time" (and how awful his proposed title is)... finishing off with a "thank you, come again!"
 * Another episode has Homer dismissing jazz as "Making stuff up as you go along" before trying it himself. He ends up singing "de"s to the tune of "Mary Had a Little Lamb". When called on it, he tries again, only doing it again with "doo". Caught again, he shouts, "D'OH!"
 * Another episode involves Marge writing a romance novel. Her inspiration was the painting on the wall behind the couch, from which she proclaimed "A book about whaling! That's never been done before! Thank you..." She then looks at the painting's title, "...'Scene from Moby Dick'."
 * Especially odd, considering a separate episode indicated that she was the one who painted the picture.
 * Yet another episode has Homer pitching ideas to Mel Gibson for movies that are all this trope. The scene ends in a subversion when Homer asks if anyone owned the rights to Indiana Jones.
 * In yet another Simpsons episode, Homer saves a troubled horse, only for Comic Book Guy to tell them that the Simpsons already owned a horse once. Lampshaded again in the same episode, when Marge starts to develop a gambling problem.


 * Similarly, Bart would love to have an elephant. Until he's reminded he had one.
 * In the episode "The Wizard of Evergreen Terrace" Homer's attempts to become an inventor after being inspired by Thomas Edison. After several disasters, the one invention that works turns out to have been invented by Edison himself but apparently unnoticed, prompting Homer and Bart to travel to Edison's workshop to destroy it. Homer decides not to once he sees that Edison himself also had a "rivalry" similar to his with Leonardo da Vinci.
 * Homer decides to split the difference and take both his and Edison's frustrations out on the Eli Whitney museum.
 * At the end of "Homer's Barbershop Quartet", the titular band are recreating the famous moment when the Beatles played a spontaneous live concert on the rooftop of their offices, on the top of Moe's Tavern. George Harrison drives past for the sole purpose of pointing out that it's already been done. Of course, the entire episode is a riff on the career of the Beatles, so pretty much everything that the B'Sharps did had been done before.
 * During a feud with kids from the town of Shelbyville, Milhouse insisted that kids from Springfield invented wearing your backpack over one shoulder, and the Shelbyvillians are copycats. A kid from Shelbyville insists the opposite.
 * Ironically, both children then bond over the fact that they share the same first name.
 * In the episode, "I Am Furious Yellow", Bart is brainstorming comic book ideas. He looks to his left, sees a conveniently placed bat, and says "Batman!" He then remembers that it's been done. So he looks to his right, where he sees a conveniently placed Green Lantern.
 * On occasion, The Simpsons rips off Family Guy: One example is the dual parodying of "I've Grown Accustomed to Her Face" (Family Guy: 2000; Simpsons: 2002) from My Fair Lady. Not only do they use the same song... they use it in the SAME CONTEXT: "I can't kill him/her, not now, despite my years of attempting it."
 * They also ripped off Family Guy with a joke where Homer tries to imitate the Fonz and ends up smashing his hand in the glass of a jukebox.
 * And then there was the "Reaper Madness" segment of "Treehouse Of Horror XIV" (2003), which caused a brief Internet Backdraft in Simpsons fandom over similarities to the Family Guy episode "Death Is A Bitch" (2000). (Basically, Death is unable to do his duties due to injury/death, the series' bumbling dad has to take over).
 * And then there's "G.I. (Annoyed Grunt)" and "Saving Private Bryan", which aired within a week of each other in 2006, and had almost the exact same plot to the letter - school assembly convinces Bart/Chris to join the Army, Homer/Bryan goes down to the recruiter's office to try to get the contract torn up, and ends up enlisting themselves, and immediately being deployed into a combat theater.
 * A lot of these similar plots airing near to each other can be attributed to topicality and Strange Minds Think Alike, since animation takes months to do.
 * The subplot of "Lisa Gets An 'A'" where Homer buys a live lobster intending to eat it but ends up getting too attached to it to do so was very similar to the Garfield and Friends short "Maine Course".
 * There's also "Binky Goes Bad" and "Krusty Gets Busted". Both of them involve the respective series' clown characters getting framed for robbery and having their name cleared by the main character (Garfield/Bart). The Simpsons episode is naturally more well-known (not least for its introduction of recurring antagonist Sideshow Bob), but the Garfield short came first (about a year earlier).
 * The episode "The Fool Monty" is essentially "The Old Man and the Lisa" crossed with the Mr. Burns subplot of "The Mansion Family". It even includes a Take That at themselves. At the end, Mr. Burns wants to punish the town by putting a giant dome on the city. Cue a scene from The Simpsons Movie and Mr. Smithers saying it's been done.
 * It was also done in "Who Shot Mr. Burns, Part I", although that wasn't a full dome.
 * "The Fool Monty" seems all about shoutouts to previous episodes. Burns in shock acts a lot like he did in the episode with Mulder and Scully, he's seen naked by Marge (and the rest of the family this time), Lisa's former ballet teacher makes only his second appearance.
 * Family Guy: The novel Brian has been working on for several years turns out to be identical to the Iron Eagle movies, and carries the ridiculous title, "Faster Than the Speed of Love".
 * At the end of the Star Wars episode, Chris points out that Robot Chicken did a Star Wars episode months ago. Peter argues that this doesn't count, because nobody watches Robot Chicken. It's also worth noting that Chris Griffin is voiced by Seth Green, who also created that show.
 * In addition, Seth MacFarlane, creator of Family Guy and voice actor for Peter, contributed voices to the Robot Chicken Star Wars episode.
 * MacFarlane also got "It's been done" jokes during the David Hasselhoff roast, a common accusation made against the man because of so many similar scenarios inside Family Guy that seem lifted from South Park and The Simpsons. MacFarlane does not seem to mind too much and is a good sport about it.
 * The series seems to have taken to lampshading this recently; with Cool Hand Peter and Viewer Mail No. 2 being standouts.
 * A recurring segment on The Alvin Show was Bungling Inventor Clyde Crashcup who, along with his long-suffering and far more competent assistant Leonardo, tried to invent the chair, baseball, jokes, the bed and dozens of other things, and seldom got it right.
 * In the Phineas and Ferb episode "Interview with a Platypus", Dr. Doofenshmirtz's evil plan is to flood the town of Danville and sell his new invention to the citizens: the Buoyancy Operated Aquatic Transport, or "BO-AT".
 * An episode of House of Mouse has a cartoon called Ludwig Von Drake's House of Genius, where Von Drake presents "new inventions" that were already done (e.g., presenting a telephone as the "Tele-finger").
 * Done on SpongeBob SquarePants when SpongeBob and Patrick are trying to come up with inventions to help Sandy. Patrick comes up with a pencil, a lightbulb, and a parallel universe. The last one is a subversion when SpongeBob claims it's a mirror (cuz it looks just like one and he sees his reflection in it). Then SpongeBob wanders off-screen and Patrick pulls it out again despairing that he had beaten to the punch when SpongeBob's reflection comes back and, in a different accent, tells Patrick that he "thought it was a pretty good idea."
 * The Pinky and The Brain episode "Brain Drained" begins with the Brain preparing a plan eerily similar to the one in the episode "Das Mouse", when he realises the similarity of these two plans. Then he brings up a backup plan that's similar to the intended plan from the episode "Snowball", which he also realises. He proceeds to file through his previous plans, every second one being a subliminal message. While the Brain is dejected about his lack of original plans, Pinky compares his situation to Tony Danza, who is noted to have talented writers. This inspires the Brain to hire would-be screenwriters to write original plans for them, then claim the plans as their own and use them as they see fit. Cue Terrible Interviewees Montage.
 * In the Western animation of Darkstalkers, Lord Raptor gets told this word by word when he tries to get into the music industry. "I'm a Zombie who rocks!"
 * The Looney Tunes Show: In "Peel of Fortune", Daffy tries to come up with an invention that will make him rich. His first three inventions are sliced bread, toilet paper and the suitcase.

Real Life

 * A number of people have been sued for plagiarism and have managed to defend themselves by showing either that the story is Older Than They Think or that it was just a coincidence. Others haven't managed to convince the jury.
 * Some patent cases also are settled when the defendant shows that the original patent is actually not the first instance of the invention. This is known as prior art.
 * The rights to King Kong are rather open, as movie studios discovered when they tried to sue Donkey Kong.
 * This is actually a case of Hoist by His Own Petard. After Nintendo released the Donkey Kong arcade game, Universal sued on the grounds that the gorilla was too similar to King Kong, and pressured the small Japanese company for a settlement. Unfortunately for Universal, Nintendo's lawyer Did Do the Research, and found out that Universal had previously won a lawsuit declaring King Kong was in the public domain.
 * Nintendo were, as you might expect, very grateful to this lawyer, and later showed that in the form of a game. What was that lawyer's name? Kirby.
 * A columnist several years ago predicted that someone was going to make a film called Saturday the Fourteenth, ripping off the Friday the 13 th series. That had already been done, in 1981, with the tagline, "Just when you thought it safe to get up in the morning."
 * The "Purple Drank" craze, a mix of alcohols and cough syrup, sometimes with soda and candy added (Skittles and certain flavored ice teas are popular ones. Yes, that combination should sound familiar). Not surprisingly a similar drink had been created a few years ago known as a Flaming Homer (a mixture of all left over alcohol in your cabinet and cough syrup, which is then lit on fire.) Simpsons Did It!
 * Purple drank is typically Sprite and prescription-level cough syrup. The prescription cough syrup is used because it contains high levels of codeine. But I always assumed they stole the idea from the Flaming Moe. I doubt the producers are going to sue.
 * It's a mostly unknown fact that softball was invented in the Netherlands during the Second World War. The lack of transatlantic communication caused by the Nazi occupation prevented the inventor from learning that his new sport had reached America before liberation. When he did find out, it did not stop him from founding the Dutch Softball Association, abbreviated as "NSB." But during the war, "NSB" was the Dutch Nazi party, so the letter combination carried an unfortunate association. The softball association had to change its name to Dutch Ladies Softball Association, which had a negative impact on softball and baseball gender emancipation.
 * A strange example as softball was played in the 19th Century United States
 * It was recently discovered that Inception has various similarities to a Donald Duck comic written by Don Rosa and published in 2002.
 * Double example: The comic was based on an idea sent in by a Duck fan just after The Cell was released.
 * Qatar plans on using an "artificial cloud" to shade their stadium for the 2022 World Cup. Turns out not only did The Simpsons come up with the idea before them, but South Park made fun of building the structure and finding out it was done previously by The Simpsons before Qatar planned on doing it.
 * William Shakespeare once said there are only 6 plots. Stephen King did as well. So did a bunch of other people. The idea that that everything's been done before is not even original.
 * Within mainstream music amoung more the more older fans it's common for them to say, It's Been Done or every is a repeat of prior things. Especially amoung female stars the fight to be "Completely new" is huge.
 * Listen to this piece of music. Now listen to this one. Even to this day, people are still confused as to who ripped off who's music. (If only they checked out the dates: Leviathan came out in 1989, whereas Record of Lodoss War came out in 1990.) And to even ask if the veteran composer like Jerry Goldsmith ripped off music from an obscure (at that time anyways) anime series is kinda unthinkable.
 * One tenet of postmodernism is that nothing we can do is original, the trick is either to do old things in new ways, or to lampshade the hell out of it.