Rule 63



""I'd make a sexy chick!""

- Brodie, Mallrats

For every given male character, there is a female version of that character, and vice versa.

They may be canonical. Most of them aren't. The internet has a fascination for producing gender swapping regardless of the context of the original character. Canon-derived examples of the trope tend to outlast their actual-canon inspirations (which are often single stories, or even short throwaway gags.)

No character is immune to this effect—not Darth Vader, not Master Chief, not Jesus—no one.

Closely related to Gender Flip. When a separate character is a female knock-off of an existing male character, you have a Distaff Counterpart; if it's male, then you have a Spear Counterpart. Crossdressers and Half-Identical Twins, of course, provide their own version of this. There's a good chance that you'll see the character in question in a Gendered Outfit (like our lovely Maria at right, here).

One of the Rules of the Internet. Can (and often does) overlap with Rule 34. Since these female versions are often cute, it can also overlap with Self Fanservice.

Anime and Manga

 * Axis Powers Hetalia, as a series where gender is essentially an arbitrary distinction, actually has official art fulfilling this rule.
 * This from Yu-Gi-Oh! fandom. "There are no women in Yu-Gi-Oh..."
 * Bakura has been struck! (SFW)
 * Jonouchi's been treated like this as well (link SFW).
 * A canonical example would be the Dark Magician Girl that appeared in the Battle City arc.
 * Let's not forget The Hero himself:
 * The Legendary Heroes arc in the anime had an odd In-Universe example with Princess Mary (Princess Adena in the dub, an NPC in the Deep-Immersion Gaming simulation designed to look like a female version of Mokuba. Exactly why Seto designed her that way is a mystery, but it helped Mokuba get to Seto by convincing her to do a Twin Switch trick when the bad guys came to nab Mary.
 * Naruto examples:
 * The title character's sexy jutsu is based on this. "Naruko" is considered an entirely separate character by many fans.
 * "Sasuko" is also susceptible to this.
 * Haku, who appeared early in the Manga (and again much later). A large portion of the community (especially Fanfic writers) seems to like the idea of Haku actually being a girl, either omitting the one actual indication of his gender or just simply having Haku and Zabuza lying about his gender.
 * Project Naruko Gender Flips the entire universe of Naruto.
 * In response to a fan letter, Eiichiro Oda of One Piece fame drew reverse-gendered versions of the main cast in chapter 545's SBS Corner. This has spread like wildfire among One Piece fans—try finding any characters that haven't been gender flipped. Not even Big Bads are immune -- Crocodile? Nope. Enel? Nuh-uh. The three Marine admirals? Seriously, NO EXCEPTIONS. (Images are NSFW.) This goes so far as to include The Thousand Sunny. Then we get Ivankov, who's canonical powers (gender bending) not only mean that he/she can do this to him/herself, but to other people as well. Did we already mention Crocodile? This one does an actually believable job, which is scary. Comes from the crazy theories of his third weakness, but it's gotten to the point where there's stuff that isn't just the character gender flipped anymore.
 * Pokémon has several prominent examples:
 * In the first season, Ash Ketchum dressed up as 'Ashley', a little blonde girl in an orange dress. She's still drawn by the fans, has her own fan clubs, and some people consider her a different character.
 * Ash has been forced to crossdress once each region after this—as a one-shot female NPC in Hoenn, and as a French Maid in Sinnoh. Guess what else has lots and lots of fanart.
 * Ash/Ashley. Yes, it exists. Wouldn't be surprising if there was also Ashley/Ashachu or Ashley/Ash/Ashachu out there.
 * Hun, a Team Rocket member from The Legend of Thunder special was (a very girly) male in the Japanese version. Guess who didn't get the memo about his gender? 4Kids.
 * Although he's never referred to as "she", and is often considered by fans just to be a man with a very feminine voice. However, the Latin American Spanish dub repeatedly calls him a woman.
 * The banned episode "Beauty And The Beach" features James entering a swimsuit contest with inflatable breasts.
 * Code Geass has a few examples:
 * Lelouch is forced into a dress in one Picture Drama, and into an incredibly skimpy belly dancer uniform in another. As a result, the fandom really likes to run with that idea.
 * Mao in the Alternate Universe series Nightmare of Nunnally is one of these. In the regular series, he was a dude Lelouch's age. In the spinoff, she's a girl Nunnally's age.
 * Black Lagoon does the gender inverting in one of its specials seen here on youtube, including an awesome male Balalaika (and Eda looking an awful lot like the cowboy mercenary she had a Gun Kata duel with). Hilarity bonus also runs for the Creepy Twins. The best part is that, in spite of having their genders swapped, the characters still have the same voice actors, who make no attempt to sound more gender appropriate.
 * Baccano! character Claire Stanfield has a sadly feminine name,right? Here, the name fits the character better. Fem!Graham is on that page, too, as is Chane Laforet as a well dressed, Tall, Dark and Handsome Bishonen. *Dreamy sigh*. Curiously, Ladd Russo and Christopher are on that page too, but they're completely unaffected.
 * From this page's counterpart on the /tg/ wiki, I give you Eduarda Elric and Rowena Mustang. Our poor title character doesn't seem too comfortable with that outfit, despite the fact that no tiny miniskirts are involved.
 * Maybe she's just wondering why she got her leg back?
 * It's true: even the most MANLY OF MEN is not immune to this. Cower in fear before female Kamina. Yes, that one. The scary bit? Even in female form he's more manly than most men!
 * Female Simon and Rossiu are adorable pre-Time Skip.
 * Kinon and Rossiu, the other way around.
 * But Male Yoko is OUTRAGEOUS!. AAAAAAAAAAAAAAAAARG! Need Brain Bleach, 5 hectoliters, directly applied.
 * Female Viral is a BAD girl with capital D, er B. Well, both.
 * A recent chapter of the Soul Eater manga made this canon. Most of the main characters (including Blair, but sadly, not Kid) became gender-swapped. How long a character stayed in his/her gender-bended form depended on how much of a Covert Pervert that character is.
 * Then again, there's still one character that seems immune to Rule 63. Then again...
 * Befriending people (through giant energy blasts or otherwise) is now twice as easy with Nanoha's male self!
 * Nanoha x Nanoha OTP?
 * Through the magic of pitch-adjusting technology, many of the K-On! songs have been gender-flipped. As have the main four characters. Azusa doesn't seem to be gender-flipped yet since they seem to have been made before she was introduced. Here's the Season 1 opening (Cagayake! Boys), and the rest can be found here. The real kicker? It's actually pretty darn good.
 * There's a joke concerning Neon Genesis Evangelion about how the cast would be more likable if they were all Gender Flipped - female Shinji would be Moe Moe, male Asuka and Rei would be badass, and female Kaworu/female Shinji would be hot. This has led to at least one gender-swapped version of the Evangelion opening, as well as some fanart. The fact that many of the characters have gender-neutral names doesn't help.
 * If it comes to 63 fanart, it heavily depends on the artist. The one above is OK but if you can look at this or this and not Squee, you're not human.
 * Of course, Shinji is just a male Nadia and Rei is a female Shinji. The decision to give everyone the opposite gender than expected of their character type must have actively registered somewhere in the minds of the creators during production of this Humongous Mecha anime Deconstruction.
 * 4chan is already doing this with Puella Magi Madoka Magica, with Madoka being a Rose-Haired Boy, Mami looking like a prince, and Homura as a long-haired Bishonen.
 * The Genderbending of Haruhi Suzumiya does this to the Haruhi Suzumiya cast, and the "new characters" it created are permanently entrenched in the fandom. "Kyonko" in particular is probably more popular than the male Kyon, and is paired with even more characters than him.
 * Kodomo no Jikan does this occasionally to look how Double Standards would apply to the current situation (such as Shirai slapping Aoki). One of the extras featured a whole chapter-long look at this.
 * Mahou Sensei Negima literally has a Rule 63 in regards to
 * There's also the fanfic Nerima Magistra Nelly Magi, which was an attempt to Gender Flip the Negima manga without the result being "too creepy".
 * Dragon Ball examples can be seen here, here, and here.
 * By far Frieza has to be the most popular when it comes to rule 63 art, mostly because of his already androgynous appearance. I mean, seriously, just look for yourself.
 * Mobile Suit Gundam 00 recently got a lot of such art, mainly directed at Tieria but no one is immune: the Gundam meisters, Graham, Billy, Patrick... even the Gundams themselves. Examples:
 * Tieria and Lockon
 * Allelujah. Sooo adorable!
 * SETSUNA AND GRAHAM AKER, Schoolgirl Lesbian-mode (SFW).
 * And just that little extra: R63-Tieria cosplaying as Yoko.
 * The title character of Ranma ½ is an canonical Gender Bender, being cursed to change into a sexy, female version of himself on contact with cold water, because he was once tossed into a cursed spring in a training session by his idiot father. While obviously a "real" aspect of the Ranma character, fandom has taken the concept even farther, naming the female side of him "Ranko" and making her an actual character in countless fan works, (many of them extremely NSFW).
 * Alas it seems only with will you find a Badass woman in the Death Note fandom. the main (formerly male) cast as women, fem!L, fem!Light and male!Misa, and (SFW) Schoolgirl Lesbians Light and L. and fem!L with Light.
 * All of Pretty Cure has been subjected to this.
 * In the one shot preview arc for Let's Bible, the heroine, Iesus, is Rule 63 Jesus Christ.
 * According to the backstory of Fate/stay night,
 * Main characters of Durarara!! also aren't safe from this. Here's the proof
 * Hayate of Hayate the Combat Butler was found to play a very convincing female (even attracting the romantic attention of three male characters in that form). His female appearance has since made several more appearances and its own name (Hermione Ayasaki) and has been fandom-paired with his gender bent form.
 * Canon example in Is It Wrong to Try to Pick Up Girls in a Dungeon?: the gods Loki and Hephaistios are goddesses in this setting.

Comic Books

 * DC Comics actually has an Alternate Universe devoted to this: Earth-11, featuring Superwoman and Batwoman as well as the very Spartan-looking Wonder Man. Fun fact: 11+52 (the total number of alternate Earths after Infinite Crisis) equals... 63.
 * Marvel Mangaverse: Characters who don't start the story off already female are replaced by females very quickly.
 * Genderbending Loki from The Mighty Thor isn't that difficult to imagine since not only is he a shapeshifter normally, but he assumed Sif's form for several story arcs for the lulz. Princesses Thor and Loki aside, The Warriors Three have also enjoyed time as the fairer sex.
 * The Avengers trio, in a fan art depiction.
 * One comic had The Authority meet their gender-flipped Alternate Universe selves.
 * The Fantastic Four once visited an alternate universe where Tony Stark was female... and married to Captain America.
 * Watchmen fandom has a fairly established body of Rule 63 fics, especially on the Kink Meme. Get used to Danielle, Wanda, Adi, Laurence, Joan Osterman, Sal and Edie.
 * An issue of Uncanny X-Men featured an evil team of male versions of several X-Women fighting Captain Britain. Most of them looked very flamboyant in those costumes.
 * Exiles once visited an alternate Earth with female Magneto and Quicksilver, and Scarlet Warlock (male Scarlet Witch).
 * The Joker:
 * He's a woman named Bianca Steeplechase in Thrillkiller and its sequel, which are set on an alternate Earth in the early '60s. Batgirl and Robin go up against her. Harley Quinn is still a girl.
 * Common in fan art too, as a search for "Genderbent Joker" on Google will reveal. You may want to keep safe search on.
 * An issue of Lobo has the Main Man dying and going to the afterlife...only to be reincarnated as an extremely masculine female version of himself.
 * The UK Dennis the Menace had a female cousin who looked was exactly like him but wore a bow in her hair and a skirt -- and was called "Denise The Menace".
 * A canonical Superboy story, "Claire Kent, Alias Super-Sister" has Superboy transformed into a girl. It's not permanent, and the story is mostly forgotten today, except as a tryout of sorts for the Supergirl concept. Mostly. There is quite a lot of fan art, and several Fan Fics, based on the premise that Clark was permanently stuck as Claire.

Film

 * The 2009 Star Trek has inspired Gender Flip fan art. For example, see a different take on the Trio of Kirk, Spock, and McCoy here. Chekov, Sulu, Scotty, and Pike show up here. On this page, we see that this trope can go in both directions.
 * Not even our favorite slasher movie kings are immune to this rule

Literature

 * "Girl-Who-Lived" fanfics are a popular Fandom-Specific Plot in Harry Potter, with either Harry being turned into a girl, or being born one. The most well-known is probably Rose Potter from the The Girl Who Lived series. An example of "Harriet Potter" (along with other Gender Flipped characters from the series) can be seen here.
 * The Dougal Dixon book Man After Man: An Anthropology of the Future, a book infamous for blatant examples of Body Horror and Nightmare Fuel is no exception.

Live Action TV

 * Red Dwarf had an entire alternate dimension where Lister, Rimmer, and Holly had female counterparts; Cat, meanwhile, had a male dog counterpart. Because dogs and cats are different genders.
 * Pops up every now and then on Sliders, Most notably in the episode Double Cross where there is a female counterpart of Quinn named Logan St.Clair.
 * Star Trek: The Original Series, in its last-aired episode, "Turnabout Intruder", tells the story of a forced Body Swap between Captain Kirk and his crazy ex-girlfriend Janice Lester. Of course, everything is sorted out at the end... though that hasn't prevented a plethora of Fan Fics, fan art, and photo manipulation about alternate scenarios where Kirk is stuck permanently in Janice's body (usually due to Janice-in-Kirk's-body being killed.)
 * A sketch on The Carol Burnett Show featured gender swapped versions of the cast of the original Star Trek.

Tabletop Games

 * Warhammer 40,000 examples:
 * Cultist-chan shows up in many /tg/ Warhammer 40,000 memes. Now, meet Cultist-kun!
 * Female Space Marines pop up now and again, but are often met with cries of Canon Defilement (also known as HERESY!) due to a supplement which states that Space Marines are explicitly all-male.

Video Games

 * Partly thanks to the entire cast being male, a significant amount of Team Fortress 2 fanart/fanfiction is Rule 63. The most frequent target is The Chick, Medic. As stated below, Nerf Now has them as characters.
 * There's actually mods to replace the Scout, Medic, Heavy, and Spy (with more coming) with female models and fan-made female voices.
 * This clip from Machinima suggests
 * Female Link or male Zelda (not to mention female/male Sheik) are popular subjects of The Legend of Zelda fanart.
 * "Tailsko," a female version of Tails, is likewise a popular subject for Sonic the Hedgehog fan works.
 * Final Fantasy VII's Cloud and Sephiroth are already very pretty. Guess what happened?.
 * Fans don't even need to make them themselves for the bloodlines of Bloodline Champions - they all have an outfit which is the opposite gender of the original bloodline outfit.
 * Even Altair from Assassin's Creed had one. Altair looks like Yuki Nagato; he just needs glasses. Shame they didn't exist back then.
 * Sol Badguy of Guilty Gear has some fan-art. Also there's the cosplayer known as Sol Badgirl.
 * From the same maker, BlazBlue experiences the same thing with female versions of Ragna, Bang, Jin and even Hakumen drawn by fans. (link NSFW).
 * As of late, there's been quite a bit of this for Hazama/Terumi as well.
 * Lost Saga not only loves to include BlazBlue characters into its game, but also allows you to buy an item that lets you play as a female version of that character, examples include Ragna and Hazama, Jin is the only exception as his female version is Noel Vermillion.
 * It's become surprisingly popular to depict Earthbound Zero's big bad, Giegue, as a female. Since Giegue's a skinny grey alien, some non-canonical anatomy comes into play.
 * On the EarthBound end of things we have Nell, Paul, Jess, Pu, Porkie, and Toni. (Definately SFW)
 * Iori Yagami of The King of Fighters. SNK's acknowledgement: by courtesy of Demitri's Midnight Bliss here. Also, Gals Fighters (Queen Of Fighters) has a character called Miss X. Oh, and Orochi Iori's blissed form is.
 * He is not the only one that suffers (or is very popular) due to this rule. In fact most of the King of Fighters have been subject to this at some point or another (save Mai for some reason). But the one that gets it the most (even more than Iori) is Leopold Goenitz of the Wildly-Blowing Wind. Yes, that guy... Oh and yes, Demitri's Midnight Bliss is the one to blame for Goeniko. There are other characters based on this concept that simply run with the idea, and the MUGEN fanbase tend to make a character out of this.
 * Nobody's surprised to see Tales of Vesperia's Yuri Lowell genderbent a lot. Since, well... y'know.
 * There are genderbent chibi figures of several famous Metal Gear characters. These are an official product distributed for nothing than fanservice. Snake is rather cute...
 * In addition to the depiction of Maria, the pretty girl plumber at the top of this page, Mario and friends have been frequent subjects for this trope. See Maria's sister Luigia, for example. (As a bonus for straight males, the previous two examples feature "Grade A" Zettai Ryouiki.) There's also this group shot. You might not want to see Bowser as a girl, but you can.
 * Though Bowser as a man has certainly been drawn thinner in Fan Art before, one would think a female Bowser would more likely be a Big Beautiful Woman.
 * Futako, the artist who drew the top picture, has since drawn both Mario and Luigi as females. She calls them the Super Mario Sisters.
 * An official version in Super Robot Wars Reversal in the case of Raoul/Fiona Gureden. Fiona is basically Raoul as a girl (and vice versa). In Original Generations, they decided to keep both branches and make them Half-Identical Twins.
 * Koihime Musou, an erotic game based on The Romance of the Three Kingdoms, in which most of the novel's male characters are female.
 * So are Sengoku Rance (partial example, as many characters remain in their original gender, e.g. Nobunaga Oda) and Sengoku Hime, with the Sengoku Jidai as backdrop.
 * This Warcraft fan art piece.
 * Touhou fandom, due to the Fundamentally Female Cast and the First Law of Gender Bending, has relatively little of this considering the sheer number of fan works. Regardless, plenty of the Loads and Loads of Characters have been subjected to this, including Yuuka, Marisa, Parsee and Yuugi, Komachi and Shikieiki, Yukari and Reimu, the Tengu trio, the IN playable characters, the Scarlet Devil crew, and even Rinnosuke (images are slightly NSFW due to advertisements). And the less said about Cho-Marisa, the better.
 * PotatOS aka GLaDOS of Portal 2 fame got this treatment here. Link NSFW... and mind, that is a real potato.
 * Star Wolf of Star Fox as females, by Fumicaworu. Creatively done, and Wolf's gender flip even looks vaguely like a cross between his character and Katt Monroe as a pink wolf.
 * An odd in-game example in Super Monday Night Combat: Unlockable uniforms turn Combat Girl and Megabeth into Cosplay female versions of the Engineer and Soldier, respectively, from Team Fortress 2.
 * On the Dragon Age front, we have 'Ms Alistair', as well as 'Madam Zevran', male counterparts of Aveline and Isabela, one of Merrill and Fenris and yet another of Fenris, possibly because he's quite the effeminitely pretty character.

Web Comics

 * Nerf Now has produced female versions of all the Team Fortress 2 characters, as well as several characters from other games, such as StarCraft. And they're all adorable.
 * Seeing as anyone and everything gets shipped together in the Homestuck fandom, this was inevitable. Gender-bent versions of Dave, John, and the Midnight Crew are particularly popular though. Of course, genderbent versions of John and Jade are quite hard to distinguish from the original, since they're so alike they could as well be Half-Identical Twins...
 * There are tons of examples on Bittersweet Candy Bowl. It started off as a favorite thing of the fans to do, but then spread to the author. Most of the time it leads to the most insane Crack Pairings.
 * Fans of Hanna Is Not a Boy's Name have made sure that Hanna isn't... well, a boy's name. And everyone else, too. Femrad (female Conrad) is pretty much a fandom meme. And that's just the tip of the genderbent iceberg.
 * Although Garii in Ménage à 3 is just a figment of Yuki's imagination, she's close enough.
 * Scandinavia and The World has a male and female version of most commonly mentioned countries, they are generally very similar in appearance (Sister Germany even has her brother's mustache).
 * Many characters in Arthur, King of Time and Space have different genders based on their arc. Tristram, in particular, is female in every arc besides the baseline, and Morgan and Nimue are actually male in the M*A*S*H* arc.
 * El Goonish Shive has a great deal of actual Gender Bender activity, which also inspires a lot of fan art.
 * This April Fools strip of Kevina And Kelly
 * An official version of this occurs in Ears for Elves. The last panel here calls the rule by name and shows what Tanna and Luero would look like when gender-flipped.

Web Original

 * Examples from That Guy With The Glasses:
 * Anne Onymous of The Wotch drew a Worksafe image of That Guy With The Glasses.
 * At one point, there was also an amusing series of videos created by (female) TGWTG fans dressing up as their favorite (male) reviewers and demanding that the fandom fix this crackfic singularity gender bend... thing.
 * In-universe, a female version of The Nostalgia Critic (the title card version) was dressed like a sultry-looking hooker for his review of Moulin Rouge.
 * For their crossover review of Sherlock Holmes (2009), Sofie Liv and Sursum Ursa dressed up (and did the review) as Holmes and Watson.

Western Animation

 * Generator Rex has an awesome in-universe example of this. Yay for surprise fanservice!
 * Metalocalypse. Dethklok had a tribute band that was composed of all women, giving each of the band members a female counterpart. Dethklok rejected them, as they found them rather creepy. Though Toki admits the female Pickles was cute, and Nathan agreed she did have nice eyes.
 * One particularly nice example of the band getting genderbent exisists here
 * Superjail has an episode where female versions of the entire cast appear, complete with a female-to-male transgender to compliment Alice and a lesbian couple in the place of the gay couple in SJ.
 * Happy Tree Friends will prove this rule disturbingly true for Flippy with a simple Deviant ART search. Although, use caution with that one, because it's usually not a female version of Flippy they're making, it's their own characters and a separate entity that's basically just if they made Flippy as a girl and then ship them with the real Flippy.
 * The Adventure Time blog posted a series of Rule 63 drawings by one of the concept artists, much to the amusement of fans. The episode "Adventure Time with Fiona and Cake" used this concept, and in a reference to this trope,
 * Given the high female-to-male character ratio on My Little Pony Friendship Is Magic, it was probably only a matter of time before male versions of the six main characters came out. A fan artist named Trotsworth has probably the most famous examples. There's even fics about it, such as The 63rd Rune and On A Cross And Arrow.
 * "Neutopia", the seventh season premiere for Futurama, features Gender Bender versions of each character. The episode even lampshades this trope when a calendar of the sex-changed characters makes a huge profit due to the "creepy fans" of Planet Express.
 * Osmosis Jones fan art examples have been seen, including cosplay of a female Thrax.
 * In-universe, the Rowdyruff Boys to The Powerpuff Girls.
 * This piece of Thundercats fanart will likely murder your childhood in an entirely worksafe way.

Other

 * Every Vocaloid (including Rin and Len) and almost every UTAUloid tend to have a genderbend. In the UTAUloid's cases, many are made by the authors themselves. People have also edited their vocal files to create a masculine/feminine version of the characters.
 * Among Mixed Martial Arts fandom, Cristiane "Cris Cyborg" Santos is considered to be Wanderlei Silva's female counterpart.
 * The mythological "earth monster" Tlaltecuhtli was not known to archaeologists to have a gender due to ambiguities in the corresponding oral tradition, but was assumed to be male because of the 'tecuhtli' ('lord') suffix. However, subsequently studied artifacts portray clothing and poses associated in Aztec art with women. How scholars interpret this varies, but Wikipedia notes: "Rather than signal hermaphroditism or androgyny, archaeologist Leonardo Lopez Lujan suggests that these varying embodiments are a testament to the deity's importance in the Mexica pantheon." Which seems to be another way to say: sooner or later, a popular character will get his or her rule 63 version.