Rule of Three



"''Good things come in threes. So do bad things. And even things that are neither good nor bad.

''Good things come in threes. So do bad things. And even things that are neither good nor bad.

Good things come in threes. So do bad things. And even things that are neither good nor bad."

Three is a magic number.

The Rule of Three is a pattern used in stories and jokes, where part of the story is repeated three times, with minor variations. The first two instances build tension, and the third releases it by incorporating a twist.

This is especially common in storytelling. The third of three brothers succeeds after his older siblings each failed. The protagonist is given three tests and receives the prize after the third. It's almost unusual to find a folktale that does not incorporate the rule of three in some form. This may be an artifact of the oral tradition, in which the stock formula of the first, second, and third attempt makes the story easier to remember.

Following on from the oral tradition, speech-writers have learnt the 'Rule of Three' - listen to a political speech- the points come in threes, from 'Ein Volk, Ein Reich, Ein Fuhrer' to Tony Blair declaring 'Education, education, education'.

The rule of three is also used widely in comedy. Many popular jokes are based on three Stock Characters (e.g. Priest, Imam, Rabbi), all in the same situation. The first two react normally, the third does something ridiculous (but stereotypically in character). In Britain, Englishman, Irishman and Scotsman jokes denigrate either the Irishman as stupid or the Scotsman as a tightwad, while the Englishman is usually the Straight Man of the gag (Unless it's being told by the Scots or Irish. When an American tells it, Englishmen are stuffed shirts.) This is why most Americans have never heard of Wales. Another (geeky) variant is the engineer/physicist/mathematician series of jokes, however, these are virtually never considered offensive, largely because the stereotypes are often jokingly accepted by the members of those three groups. (e.g. The engineer is overly practical, the physicist makes large assumptions, and the mathematician comes up with a correct, but useless answer; these are played up for humourous effect, but have some valid basis)

A more popular variation on the rule is to repeat the same joke or concept three times, but put a twist on the third one that makes it funny again. One version of this is The Triple, wherein a character lists three items - the first two logical and serious, and the third applying a twist or joke. For example, a character might say to a bald person, "Can I get you anything? Cup of coffee? Doughnut? Toupee?" (From The Dick Van Dyke Show.)

Alternatively, the twist can come during the second iteration (such as Chekhov's Skill) failing the first time it's used only to return to its original form on the third pass; this version tends to accompany Chekhov's tropes.

The Overly Long Gag could be seen as a subversion of the Rule of Three, because it fails to deliver the expected twist.

In art, there's a rule of thirds where putting items in the intersections between thirds-lines draws more attention and is more visually appealing than plonking them right in the center, which is considered boring. In design, particularly three-dimensional design such as shop displays, groups of three objects, or objects arranged to form a triangle, are considered most attractive to the eye.

The Rule Of Three may be a subtrope of a more general psychological phenomenon, as threes are well-noted in all forms of culture. Films, books and plays come in trilogies. They have a Three Act Structure, a Beginning, Middle and End. Counts of three elements are used widely in rhetoric, writing and myth: "Ready, aim, fire", "Veni, Vidi, Vici", "Lights, camera, action", "Reading, 'riting, 'rithmatic," "rhetoric, writing and myth". Just try and think about how many times you've heard the phrase, "On the count of three..."

A constructed phrase such as "Veni, Vidi, Vici." that has three grammatically and logically connected elements is known as a Tricolon. When the three elements increase in length, it's a Tricolon Crescens.

This is why there are Power Trios and Terrible Trios.

Variations on this trope include uses of 5, 7, 12, and convienent multiples of five afterward (i.e., 25, 50, but not 35 or 70).

Sub Tropes include Three Wishes, These Questions Three, Third Time's the Charm, Trilogy Creep, On Three, Counting to Three, and The Three Certainties in Life.

See also Basic Conflicts and other plot devices which often come in Threes or Sevens, and Three Rules of Three, a wiki guideline. Not to be confused with Four, unless you're counting elements, bodily fluids, and other dimensions.

Related to other rules of three in number only or in politics.

Not to be confused with the rule of thirds.

Advertising

 * It's a general law of advertising that the product will be mentioned at least three times, to ensure it lodges firmly in the brain.
 * Nick At Nite has run commercials for itself, emphasizing this type of comedy bit and going so far as to call it 'the triple'.
 * "Head On, apply directly to the forehead. Head On, apply directly to the forehead. Head On, apply directly to the forehead."
 * And its lesser-known sister ad: "Freedom from hemmorhoids, FREEdHEM hemmorhoid cream. Freedom from hemmorhoids, FREEdHEM hemmorhoid cream. Freedom from hemmorhoids, FREEdHEM hemmorhoid cream."
 * A Toyota commercial has a hybrid car speeding along with three black horses, three white horses, three hang-gliders, and three fighter jets to show that soft and edgy can get along.

Anime & Manga

 * Lampshade Hanging: Keroro Gunsou episode 9 has Moa blowing up Giroro and Keroro twice in a row. Then it happens a third time, and the narrator explains that this is due to the conventions of humor.
 * In Dragonball Z, before King Kai (King Kaio) agrees to train someone, they must make him laugh with a joke. Tien performs the multiform technique to create 3 bodies just before shouting the punchline. Thus making his joke 3 times funnier.
 * Rule of Three is referenced in Golden Boy by a couple of proverb-misquoting Yakuza members: "Even Buddha only waited three times."
 * Suzumiya Haruhi: The third has Itsuki state that  three times in a row.
 * In Transformers Armada, the ultimate weapon, the Hydra Cannon, is made of three smaller uber-weapons, the Star Saber, Skyboom Shield, and Requiem Blaster. Each of these is itself made of three Mini-Cons.
 * Specifically invoked by Batou in Ghost in The Shell 2: Innocence.
 * In One Piece there are three marine admirals: Akainu, Akojiki and Kizaru
 * As well as three great powers: the Marines, the Seven Warlords of the Sea, and the Four Emperors
 * The Monster Trio in the Strawhat crew consists of Luffy, Zoro, and Sanji
 * In Fairy Tail there are three true Dragon Slayers: Natsu, Gajeel and Wendy.
 * Also there was three active S-Class mages in the guild: Laxus, Erza, Mystogan. Then: Erza, Mirajane and Mystogan. Currently Erza, Mirajane, Gildartz.
 * In Yu-Gi-Oh!, there are three Legendary Dragons and three corresponding Legendary Heroes. We also have the Blue-Eyes Ultimate Dragon and Cyber End Dragon, formed by fusing three of the same monsters into one. Egyptian God Monsters, of which there happen to be three, demand a sacrifice of three monsters to be summoned. There are also three levels of the Orichalcos: Seal of Orichalcos, Orichalcos Deuteros, and Orichalcos Tritos. There are three powerful magicians (Dark Magician, Dark Magician Girl, Magician of Black Chaos) that form a trio.
 * And three Phantom Beasts. And three Wicked Gods. And the English manga was published as three series (Yu-Gi-Oh! for the first seven volumes, Yu-Gi-Oh! Duelist for Duelist Kingdom onward, and Yu-Gi-Oh! Millenium World, following the Duel City finals).
 * GX even has three Kaiba expies.
 * The 3 kids Maurice, Maeter, and Linck in Eureka Seven, as well as the number of times Nirvash and The End fight each other.
 * Eyeshield 21 ends with 333 chapters. Many of the close friendships in the series are in groups of three.
 * Dokuhime has triplet princes who were predicted to be the "perfect child, protecting child, and destroying child", the last one having a tell-tale birthmark (the king loved them so he marked the other 2 and raised them all the same). Sure enough, one is, another is  , and the 3rd  , but that hasn't yet proved anything. Despite being triplets they no longer look the same: the one who's   looks older while the one who   looks younger.
 * Vampire Game has 3 princes who are.

Comics
"Art Spiegelman explains how a drawing of three rocks in a background scene was Ernie's way of showing us there were some rocks in the background. It was always three. Why? Because two rocks wouldn't be "some rocks." Two rocks would be a pair of rocks. And four rocks was unacceptable because four rocks would indicate "some rocks" but it would be one rock more than was necessary to convey the idea of "some rocks." --Scott McCloud"
 * Characters in Sláine constantly refer to things in groups of three - three great silences, three sorrows, etc.
 * The irreducible simplicity of Ernie Bushmiller's Nancy depends in part on the principle of "the three rocks".

Fairy Tales and folklore

 * Common. A selection:
 * "Goldilocks and the Three Bears" is built around this trope. The chairs are too hard, too soft, and just right, the porridges are too hot, too cold, just right, and so on.
 * In "The Three Billy Goats Gruff", the 3rd and largest goat defeats the troll.
 * "Cinderella" traditionally goes to the ball 3 times before losing her shoe. Later, the 2 step-sisters each try the shoe on before Cinderella steps forward.
 * The "Three Little Pigs": the first 2 pigs' houses fail to ward off the Big Bad Wolf, while the 3rd's brick house remains sturdy.
 * In the Grimms' "Snow White" story, the wicked Queen makes three attempts on Snow White's life (a cursed comb, strangling her with a bodice lace, and the famous poisoned apple).
 * In "Rumpelstiltskin", the title character gives the miller's daughter three days to guess his name.
 * After he spun for her for three nights.
 * In "Jack and the Beanstalk", Jack steals three treasures from the giant: a bag of gold, a goose that lays golden eggs, and a singing harp.
 * "The Honey Princess": Three princes are set to accomplish three tasks in order to win three princesses' hands in marriage.
 * "The Three Spinners" help a girl against an impossible spinning task.
 * In "Brother and Sister", it is the third stream that Brother drinks from; it is the third time he goes out to hunt that the king finds Sister; it was the third time she returned from the dead that her husband caught her and brought her back to life.
 * In "East of the Sun West of The Moon", the heroine meets three women who give her gifts; she uses them to bribe her way to her husband, and the third time, he is not drugged to sleep.
 * In "Maid Maleen", when she is pretending to be the bride, she speaks to three objects; the bride must find out from her three times what she said, and the bridegroom figures out the substitution.
 * In "The True Sweetheart", the heroine goes to the ball three times.
 * Anecdotes have plenty of examples. For an example, three nation anecdotes.

Film
"One...two...five!
 * In the film Teeth, Dawn's nether region severs exactly three penises on screen.
 * In Indiana Jones and the Last Crusade, Indy must pass three tests (The Breath of God, The Word of God and The Path of God) to get to the Grail temple.
 * Then comes Indiana Jones and the Kingdom of the Crystal Skull. "Three times it drops..." Hoo boy.
 * Monty Python and The Holy Grail: "Who would cross the Bridge of Death must answer me these questions three, ere the other side he see....". For bonus points, the trope is subverted four times; the first time, the three questions are all easy, so the knight easily crosses. The second knight unexpectedly receives a third, difficult question which results in his death, while the third knight unexpectedly gets an easy question again but fails to answer it correctly and dies. On the final set of questions, King Arthur subverts it again by asking a question back to the bridgekeeper, resulting in the bridgekeeper's death.
 * Possibly five times, as instead of the usual three knights/questioners/Billy Goats Gruff, there's three plus Arthur.

Three, sire.

Three!"

"Dean Richmond: Can I get you anything? Juice? Coffee? Rack of lamb?"
 * Additionally "...then thou shalt count to three, no more, no less. Three shall be the number thou shalt count, and the number of the counting shall be three. Four shalt thou not count, neither count thou two, excepting that thou then proceed to three. Five is right out."
 * A deleted scene shows Arthur and Bedevere about to cross a lake, only to be accosted by the bridgekeeper again, who says, "He who would cross the Sea of Fate must answer me these questions twenty-eight!" After some deliberation, Arthur and Bedevere toss him into the lake and continue on their way.
 * Airplane!!. During the landing sequence, Dr. Rumack (Leslie Nielsen) steps into the cockpit three times and says "I just want to tell you both good luck. We're all counting on you" in exactly the same way: once as they begin the descent, once in the middle of the landing, and once after the plane is on the ground.
 * Robert Rodriguez wove multiple instances of the Rule of Three into his scenario for El Mariachi. Example: The Big Bad, a heavy smoker, is twice seen striking a match off his resentful Dragon's cheek; the third time it happens, the Dragon is doing it to the (dead) Big Bad. In his book, Rebel Without a Crew, Rodriguez calls this "the kindergarten school of filmmaking", what he used to write a script that was interesting but also (and more importantly) quickly finished.
 * Guy Richie's first two films, Lock, Stock and Two Smoking Barrels and Snatch feature dialogue exchanges where two characters repeat the same line of dialogue three times while responding to another character. "No, Harry, you can't" in the former and "Yeah, dad, you told us" in the latter.
 * In Austin Powers, Dr. Evil's Mook Mustafa will answer a question if asked three consecutive times. The scene with him in The Spy Who Shagged Me uses the Rule twice. Austin discovers his weakness when he asks one question three times, then he asks another question three times, and finally on the third question he asks it once, then says, "Do I really have to ask you three times?" and asks it two more times, but Mustafa refuses to answer because he interrupted the questioning with a different question. Then Mustafa gets shot.
 * In National Lampoon's Christmas Vacation Clark asks his cousin-in-law, Eddie, "Can I refill your eggnogg for you? Get you something to eat? Drive you out into the middle of nowhere and leave you for dead?"
 * Dead Men Don't Wear Plaid uses Reardon's Berserk Button thrice: the first time introduces it, the second incorporates it into a Stock Footage gag, and the third time precipitates the climax.
 * The Three Stooges. (Well, there were actually 6 of them, but never more than 3 in any one production.)
 * On the other hand, the Marx Brothers arguably did their best stuff when there were four of them.
 * Even when all four appeared, it was really the three of them and Zeppo.
 * Beetlejuice, Beetlejuice, okay, stopping now.
 * Beetlejuice!
 * The swedish classic Äppelkriget (War of the Apples) takes this for a very odd twist. At one point the story segues into the backstory of three brothers who go to the city to find fame and fortune. On the way, they stumble over an old book, a carpet with a hole in it, and a dead bird, all of which the two eldest brothers reject, but the third brother takes with him, thinking that they "could be useful". When they apply for jobs, two brothers fail the psych test, but the third uses the book (a psychology textbook) and succeeds. The two eldest fail to impress the ladies, but the youngest wears his carpet as a trendy outfit and is an immediate hit. Later they're all broke, but the odor of decomposing bird leads the youngest to a stash of cash in an old recliner. Finally they've used up the money, and go back to the farm to hang themselves... and as it turns out, only the youngest managed to do that right, too.
 * The Trench Attack from Star Wars: A New Hope. First attack run, easily blown to pieces by Darth Vader. Second run "Negative, it didn't go in." Third run, Luke's all clear; he blows that thing and goes home!
 * The Empire Strikes Back features three uses of this:
 * Darth Vader Force-choking his subordinates. First, he chokes the incompetent Admiral Ozzel via video monitor and promoting Captain Piett to his place. Later, Vader kills Captain Needa for not capturing the Falcon. Then at the end, when the Falcon jumps into hyperspace and escapes, Piett expects certain death but Vader just walks off the bridge.
 * Unlike the other two, Piett didn't actually screw up. He did disable the hyperdrive, the rebels just fixed it faster than expected, and there wasn't much he could do about that. This may be why Vader spared him.
 * Director Irvin Kirschner, in the DVD commentary, says Vader is too upset that the Falcon escapes, despite the Imperials sabotaging the hyperdrive, that he merely forgets to kill a minion. Accordingly, Piett and the other officers were right to be afraid as he stormed off the bridge.
 * The Millenium Falcon trying to jump into hyperspace. First they're being pursued by a Star Destroyer away from Hoth; Han attempts to jump into hyperspace but nothing happens. Then, after leaving the asteroid field and having supposedly repaired the hyperdrive, they try again and again it fails. Later, with Lando now at the controls, and with the hyperdrive supposedly fixed by Lando's mechanics, they try for the THIRD time and it still fails to go into light speed because the Empire had deactivated it! The twist is that R 2 D 2 fixes it in time for their escape.
 * C-3PO spelling out the ridiculous odds against whatever they trying to do. First he says that the odds of Han and Luke surviving a Hoth blizzard are 725 to 1. Then he says the odds of successfully navigating an asteroid field are 3720 to 1. (Prompting Han to reply "Never Tell Me the Odds!") Finally, he tries to tell Han the odds of surviving a direct assault on a Star Destroyer, but Leia interrupts and tells him to shut up.
 * The climactic battle in Return of the Jedi cuts between three different sets of action and location: the forest battle, the space battle and the duel between Luke and Vader in the Emperor's throne room.
 * In Attack of the Clones Obi-Wan, Anakin and Padme are held captive in the Geonosian arena and separately has to fight three different beasts, an Acklay, a Reek and a Nexu.
 * A Sound of Thunder combines this with a Shout-Out to Capricorn One when Hatton congratulates the first Time Safari customers: "Today you stood shoulder to shoulder with Columbus discovering America. Armstrong stepping on the moon, Brubaker landing on Mars."
 * Fight Club. "That's three times you promised."
 * Gremlins: Oh, man, does the Rule Of Three apply here big time with the rules of caring for a mogwai. 1) Keep it out of bright light, 2) Do not let it get wet and 3) No matter how much it cries or how much it begs....never let it eat after midnight.
 * Pan's Labyrinth implements this in almost everything within the plot, as emphasized and confirmed by the director in DVD commentary, ranging from the number of a specific set of characters, towards the number of tasks the main character must accomplish.
 * Unfaithfully Yours had three fantasies over how the main character would deal with what he thought was his wife's adultery.
 * In Tapeheads, the owner of Fuzzball Records tries to get the main characters to make him another video "on spec" (i.e. for free) by mentioning that "All good things come in threes." Josh retorts that it's not good things, but celebrity deaths, that come in threes.
 * Run Lola Run loops three times through the same series of events, with minor to snowballing changes in each iteration.
 * Sherman Klump is asked a Triple in The Nutty Professor remake:

"Joker: Do you know how I got these scars on my face?
 * When Goldfinger tries to kill James Bond with the industrial laser, he tells him, "The reason for our first two meetings is now clear to me. I do not intend to be distracted by a third."
 * The Dark Knight. The Joker twice does the "Do you know how I got these scars on my face?" line in a prelude to doing something nasty. The third time he's got Batman pinned.

Batman: No, but I know how you'll get these! (shoots his forearm blades into the Joker's face)"


 * Showing that it's not always good, it's used in Triumph of the Will, and later, as a heroic example, Star Wars.
 * "Every magic trick has three parts or acts: the Pledge, the Turn and The Prestige."
 * In the DVD Commentary for Mean Girls, Tina Fey sarcastically notes that the scene where Cady & co. are trying to arrange for Aaron to catch Regina cheating on him follows "the comedy rule of twos" and that there should really be a third method they try.
 * Claudia does indeed try to kill Lilli three times in Snow White a Tale of Terror, but the first two are different from the original fairytale. She first tries to bury her in a mine cave-in and secondly by making trees fall in the forest.

Jokes
"Farrah Fawcett died and went to heaven. Saint Peter said "You were very good on Earth, so you have been granted one wish." Farrah thought for a bit and said "I wish for the safety of all children on Earth." Half an hour later, Michael Jackson arrived in heaven.
 * A joke in 2009 uses the Rule of Three to explain the three close celebrity deaths that year.

Michael Jackson was surprised to find himself in heaven, but even more surprised that he was once again black. "Saint Peter," he said, "I worked pretty hard to lighten my skin over the years. Can you fix it?" Half an hour later Billy Mays arrived in heaven with some OxiClean."


 * Jokes in general tend to make very heavy use of the Rule of Three, especially those following the "Blonde/Brunette/Redhead" or "Nationality/Nationality/Nationality" formula.

Literature
""The [spaceship's] new computer was of the standard "I-tell-you-three-times" variety, a triple brain each third of which was capable of solving the whole problem; if one triplet failed, the other two would outvote it and cut it off from action, permitting thereby at least one perfect landing and a chance to correct the failure. -- The Rolling Stones (1952)"
 * Beowulf makes this trope older than the English language. Through the course of the story Beowulf fights three monsters: Grendel, Grendel's mother, and the Dragon. This doesn't end well.
 * Discworld
 * The witches coven in Lancre consists of the Maiden, the Mother, and the... er, Other One, much to Granny Weatherwax's indignation.
 * Tiffany Aching's attempt at making a shamble (sort of a witch's Swiss Army Knife). Makes one... fails. Makes another one... fails. On her third attempt,
 * "What I tell you three times is true", from The Hunting of the Snark by Lewis Carroll.
 * "I tell you three times" is an override command to the supercomputer in the science fiction novel Stand On Zanzibar (1968) by John Brunner.
 * It's also the command for Gay Deceiver to store an instruction in permanent memory in The Number of the Beast (1980), by Robert A. Heinlein.
 * Based on the design philosophy that any machine or computer your life depends on should have triple redundant failsafes. The 'tell you three times' protocol was admittedly a lazy shorthand in violation of his own principle. Zeb demonstrated himself what a bad practice it was by using it to execute commands faster than they can be given consideration, whereas three honestly separate steps may have prevented him from jumping the gun.

"Dutton: ...while there are three bears, three chairs and three bowls of porridge in Goldilocks and the Three Bears,* there are actually four characters. The story would better support Booker* s theory were it Goldilocks and the Two Bears."
 * A story by Raymond F. Jones in the February 1951 issue of Astounding Science Fiction was titled "I Tell You Three Times", and related to computer controls. Could this be the source of the two uses above?
 * Possibly, although The Hunting of the Snark has been a recurring motif throughout sci-fi; for instance, the Nostromo was originally going to be called the "Snark".
 * The absurdist holy book Principia Discordia is based on a Rule of Five, which bleeds over into such works of Discordian fiction as Illuminatus!
 * The alien race (dubbed the Ramans) that created the gargantuan space object in Rendezvous With Rama by Arthur C. Clarke apparently do everything in threes -- triple motifs litter it. (It is implied they had three hands, and presumably also three legs). The last line of the novel uses this for a stinger. Years later, this fact served as a handy Sequel Hook for Clarke when he decided to let Gentry Lee write follow-ups.
 * “Yet across the gulf of space, minds that are to our minds as ours are to those of the beasts that perish, intellects vast and cool and unsympathetic, regarded this earth with envious eyes, and slowly and surely drew their plans against us.” (H G Wells 1898 War of the Worlds, opening paragraph). “How beautifully underplayed is that adjective ‘unsympathetic’.” (Brian Aldiss, Trillion Year Spree p. 152).
 * Stardust: The King of Stormhold has three remaining sons. Also subverts the youngest brother convention by making him pure evil, and the oldest a caring and decent man. The middle brother is a useless sex maniac. The youngest son is also the Seventh Son.
 * Also subverted in the film in that the King has four remaining sons. One is Too Dumb to Live, and is quickly pushed out of the tower by his brother, who has an eye for opportunity.
 * The Hobbit: "Third time pays all."
 * Other Tolkien examples: there are three Silmarils, three Elven Rings of Power, three races that got Rings of Power, three groupings of Elves of the Light, three ancient tribes of noble Men, three archaic clans of Hobbits, and three survivor states of Numenor (Arnor, Gondor, and Umbar). Melkor disrupts the Music of the Ainur three times.
 * There are also nine Nazgul. Nine is thrice three, and a very important number in Norse Mythology.
 * Dennis Dutton might have some good points about the flaws in Christopher Booker's The Seven Basic Plots, but he really shows his ignorance of tropes when he tries to attack Booker's use of the Rule of Three:

"Mike: When I think of wisdom, I think of three names: Solomon; Confucius; Grignr."
 * In A Christmas Carol by Charles Dickens, the Ghost of Christmas Past and the Ghost of Christmas Present do not change Scrooge's mind. It is the third ghost, the Ghost of Christmas Yet To Be, who convinces Scrooge to change his ways.
 * Not entirely true. By the end of the Ghost of Christmas Present's visit, Scrooge is shown a pair of street urchins freezing to death and shows compassion for them, only to have his earlier harsh words thrown back in his face. The Rule of Three still applies to the story structure, though.
 * Only in certain movie adaptations. In the original story Scrooge is slowly repenting of his ways from the very first ghost, and has fully repented by the end of the second. He even begins his time with the third by stating that he is a different man than he was, and is eager for the spirit to guide him further. Unfortunately, the Ghost of Christmas Yet To Come isn't the friendly sort.
 * Shakespearean examples:
 * King Lear has three daughters to whom he intends to leave a third of his kingdom each. (However, he gets annoyed with the third one and ends up giving his kingdom to the other two).
 * When is fatally stabbed in Romeo and Juliet, he curses the Montagues and Capulets three times ("A plague on both your houses!") before dying, thus ensuring that the curse comes true.
 * The Merchant of Venice has three caskets, of which the third chosen is successful.
 * Macbeth alone contains too many examples to count, most coming from the three witches.
 * And therefore also the amount Witches like to assemble in, 'cause two is just an argument.
 * In Dante's Inferno, Satan has three faces, eternally chewing on Judas, Brutus, and Cassius.
 * Also, Hell, Purgatory, and Paradise all have 9 levels, grouped into threes. In Hell, three circles apiece are devoted to sins of Incontinence, Violence, and Fraud; in Purgatory, atonement is performed for sins that involve Bad Love (Pride, Envy, and Wrath), too little love (Sloth), and too much love (Avarice, Gluttony, and Lust); and in Paradise, saints dwell in nine concentric spheres that surround the Earth, beyond which God lives. The Divine Comedy actually contains many examples of the Rule of Three, and other numerology.
 * In the Dresden Files books, all fae are bound by whatever they say 3 times. Harry mentions it several times throughout the books.
 * Also, there are three main Vampire Courts (not counting the one in Asia). As of the most recent books,.
 * Well, after the events in Changes
 * Also the white court is comprised of three major houses.
 * The Summer and Winter factions of the fae are each ruled by a Queen, a Lady, and a Crone.
 * Also there are Three factions of Fae: Winter, Summer, and the Wyld Fae.
 * There are Three Knights of the cross, with their three holy swords.
 * the events of dead beat involve three trying to find.
 * In The Neverending Story Atreyu must pass three gates to reach the southern Oracle. (In the movie the third gate is left out and the first replaced with one that shoots laser beams. duh.)
 * Several examples in the Harry Potter canon: Harry, Ron and Hermione form a Power Trio, whilst Malfoy is always flanked by Crabbe and Goyle; three champions, one from each of the three wizarding schools, are supposed to compete in the Triwizard Tournament, which itself is comprised of three challenges; there are three Unforgivable Curses as well.
 * The Triwizard champions example is a subversion, since Harry is an unexpected and unprecedented fourth competitor.
 * There are three Potters.
 * In the seventh book, Luna, Neville, and Ginny make up their own trio.
 * The founders of three of the four houses welcome students of all types (the fourth one abandoned the school and left a monster as a parting gift because he wanted it to be pure bloods only); in the seventh book, students from three of the four houses are La Résistance and hiding in the Room of Requirement (the fourth one is Les Collaborators and can't or won't join them), and three of the four houses are seen fighting in the Battle of Hogwarts (the fourth is sent to the dungeons, although their head professor does battle).
 * While they've met many times, Harry defeats Voldemort three times: as a baby, in first year, and in final year.
 * Harry also defeats Voldemort (or at least a horcrux of him) in book two.
 * "...Born to those who have thrice defied him, born as the seventh month dies --"
 * The symbol of the Deathly Hallows is triangular.
 * Also, there are three Deathly Hallows themselves; the Resurrection Stone, the Invisibility Cloak, and the Elder Wand. They were created by the three Peverall brothers: the eldest was killed for the wand, the middle killed himself to be with his dead wife, and the youngest lived to old age by "hiding from Death" with the cloak. In the movie the first two brothers are mostly silhouettes while the third brother is (more or less) fully lit.
 * In Dan Abnett's Gaunt's Ghosts novel Only In Death, "A traditional Tanith toast took three parts." So Larkin and Rawne toast "Old Ghosts," "Staying alive," and "Ibram Gaunt".
 * In the classic MS Ting of The Eye of Argon, Mike and the bots riff:

"Bella: About three things I was absolutely positive: First, Edward was a vampire. Second, there was a part of him, and I didn't know how dominant that part might be, that thirsted for my blood. And third, I was unconditionally and irrevocably in love with him."
 * In one of Mercedes Lackey's novels, a new magic user of Native American heritage was surprised he had to do something 4 times where the Europeans were equally bound to do the same thing 3 times. The 4 directions, donchaknow!
 * Romance of the Three Kingdoms didn't stop at the title for this one:
 * The best known example would be the three heroes Liu Bei, Guan Yu and Zhang Fei, who not only became best friends but blood brothers.
 * Liu Bei would later have to make three separate visits in order to convince the tactical sage Zhuge Liang to join them.
 * Guan Yu would later become leader of his own three man team, with Guan Ping and Zhou Cang.
 * Averted with Sun Quan, who's leading a nation while burdened by a legacy left behind by his father Sun Jian and elder brother Sun Ce, both of whom are dead. His close confidante Zhou Yu and sister Sun Shangxiang may constitute a new three in formation.
 * Guy Gavriel Kay's Last Light of the Sun features an in-character subversion. Alun ab Owyn, who comes from a culture that is very big on the Rule of Three, hears a creature roar two times. When it doesn't roar a third, he's surprised, until he realizes that triads are a human invention, and unrelated to ancient monsters.
 * The third Warriors series is called Power of Three, and has three protagonists.
 * And their names have three syllables each.
 * Featuring three chosen ones.
 * In The Night Angel Trilogy lessons at The Chantry (a women's school of magic) are taught in threes, supposedly for ease of recall.
 * The concept of book trilogy to begin with. The best-known example is The Lord of the Rings. Executive Meddling is what caused that one to be three books, though. It's just one novel, internally divided into six books.
 * And mocked by the 'ever increasingly misnamed Hitchhikers trilogy' (five books, sixth pending).
 * Ref. The Lord of the Rings, maybe "hexalogy" would have been too much of a pun? After all, "hex" is also German/old-English for "witch" or "magical curse" (hence the FPS Hexen).
 * In a Sci-fi story "a little lubricant" (yes, ahoi Double Entendre) the third spaceship makes it back to Earth.
 * The entirety of Wil McCarthy’s novel The Collapsium is structured this way. It’s broken into three “books,” Once Upon a Matter Crushed, Twice Upon a Star Imperiled and Thrice Upon a Schemer’s Plotting, and each begins with a nearly identical setup and set of challenges for the main character. But with each iteration, the complexity of the story takes a step up, until the final section, where everything goes to hell and plot threads from all three sections pay off. By the author’s own admission, the novel was written as a modern hard-SF fairy tale, so Rule of Three is used very deliberately.
 * Lampshaded and made an explicit magical rule in the Percy Jackson and The Olympians books, where the number three is sacred (three Furies, three Fates, three sons of Kronos atop three thrones), and so Half-Blood heroes going on quests are allowed only two companions. Breaking this is seen to invite trouble.
 * Diana Wynne Jones's book Power of Three has this in spades, unsurprisingly. The main characters are three siblings; there are three peoples living on the Moor - Lymen, Dorig and Giants; there are three Powers, Sun, Moon and Earth. The children's father performed three tasks to win their mother, and there are three exchanges of gold collars before the conflict between the peoples can be resolved.
 * In Beyond The Wall by Ambrose Bierce, Dampier heard a knocking on the wall three times. The firs time he was skeptical, the second time he answered the knocking, the morning after the third time he was discovered dead.
 * Three by Ted Dekker?
 * Moby Dick has three threes: The chapter The Chase - Third Day marks the end of the book. Furthermore, there are three mates aboard the Pequod, Starbuck, Stubb and Flask; and three harpooners, Queequeg, Daggoo and Tashtego.
 * In Graham McNeill's Warhammer 40000 Ultramarines novel The Killing Ground, the Grey Knights subject Uriel and Pasanius to three tests of whether they are tainted.
 * Similarly, in James Swallow's Blood Angels spinoff story "The Returned", Tarikus is subjected to three tests of whether he is tainted. They are explicitly billed as tests of his mind, body, and soul.
 * The titual character of Paulo Coelho's The Alchemist believes that anything that happens twice WILL happen again. He is not proven wrong.
 * Lampshaded in Sergey Lukyanenko's The Stars Are Cold Toys by an alien living computer who wonders about the human fascination with the number three. The humans are stumped, and the best explanation they can come up with is "two is not enough, and four is too much." Surprisingly, the alien is satisfied with the answer.
 * In the Star Trek Deep Space Nine Relaunch, the number three appears to have considerable significance for the cultures involved with the Wormhole Aliens; the Eav'oq, the Bajorans, and the Ascendants (who themselves make three, obviously). Connected to this, we have the trio of the Voice, the Hand and the Fire. Further, there are nine orbs (three times three), and nine Emissaries. The Wormhole Aliens certainly like the number three, though for what reason (other than this trope) is as yet unclear. Finally, the Hebitians, a race of Precursors on Cardassia, also demonstrate a great love of the number. This may not be coincidental; frequent hints that Hebitian culture is connected to that of the Bajorans suggest we have a whole interconnected spiritual community valuing the rule of three.
 * A Song of Ice and Fire's Arc Number is usually seven, but the Rule of Three still pops up a few times.
 * Jaqen H'ghar owes Arya three life debts, and in true folktale fashion she wastes the first two on trivial vendettas and makes creative use of the last one to get what she really wants.
 * Runs deep in the Danaerys chapters. She's the last of three children, she has three dragon eggs, three handmaids, and three bloodriders, etc etc. When she is scouting out from Vaes Tolloro, she sends each of her three bloodriders in a different direction. The first two come back empty-handed, the last one takes a long time but ultimately returns with three emissaries from Qarth, a city ruled by three major guilds...
 * Speaking the name of Hastur in the Cthulhu Mythos.
 * In Teresa Frohock's Miserere an Autumn Tale, Lucian denies Catarina three times. Rachael specifically points this out to Caleb: It's important.
 * In Master of Five Magics and its sequals, sorcerers must recite a spell three times to make it work, and each recitation is more difficult to enunciate than the last.
 * Twilight gives us this memorable gem:


 * In Devon Monk's Dead Iron, LeFel tries to invoke this on Jeb Lindson -- he shouldn't have to kill him more than three times.

Live Action TV
"Jon Stewert: I know comedy typically comes in threes. We threw that fourth one in there because we like to fuck with the structure."
 * It seems like standard procedure for the parents in a Dom Com to have three children. The Brady Bunch (twice over,) Growing Pains, Home Improvement, Roseanne, The Nanny, Full House, Reba all involve the three children of the protagonists. The common reason seems to be that it covers all bases; the oldest can have typical teen problems (dating, driving, etc.), the middle can have the kid problems (first day of school, etc.), and the youngest can either sit and look cute or say random funny things. The big reason for the Cousin Oliver is to bring in another cute one when the child actors have the audacity to age and upset this delicate balance.
 * Demonstrated extensively on The Daily Show; subverted at least once.

"Johnny (reading a list of things he forgot to do in order of most recent to oldest): Call Marilyn Monroe to ask her to a dance...Call Marilyn Monroe to ask her to a movie...call Marilyn Monroe to ask to take her to dinner...remember to get Marilyn Monroe's phone number."
 * Humorously subverted by Johnny Carson on one episode of the Johnny Carson Show.

"Tina: Was that one for fun too?
 * "Hi, I'm Larry. This is my brother Daryl, and this is my other brother Daryl."
 * When Tina Fey hosted Saturday Night Live, she was coached on acting by guest star Steve Martin, who slapped her early in the monologue for her self-doubt, then slapped her again later just for fun, and then one more time immediately afterwards.

Steve: No, that was the Comedy Rule of Three."

"Crow (in Kirk's voice): We have had many wars like this in our own history. Our Civil War of Earth. Our World War one and two. Our Krinkleganglium Wars of Kromulon Thirteen..."
 * Star Trek captains (especially Picard) would frequently list off three examples of some well-known cultural phenomenon. Typically, two of them would be what we would consider "classic" examples, and one would be either contemporary to us, or alien. For example, he might say, "Ah, yes, the great poets of history; William Shakespeare, Walt Whitman, Zyglorty Mospiqxot of T'pingnit." Or, "I've always been interested in classical music; Bach, Beethoven, the Beatles." (Red Dwarf did this precise gag with "Mendelssohn, Mozart, Motorhead".)
 * This tendency wasn't lost on the writers of Mystery Science Theater 3000, who'd spoof it on a regular basis.

"Leonard: I was just glad that Sheldon didn't rat me out to the Landlord. ... Or to the police. ... Or to Homeland Security."
 * One episode of ''Star Trek the Next Generation features this joke from a man claiming to be a historian from the 26th century. Talking to Geordi, he mentions several blind artists by surname, ending with (Stevie) Wonder. On rewatching this episode, one realises that this is meant to be a clue that he isn't from the future but from the 200 years in the past.
 * When Star Trek the Next Generation the Enterprise got caught in a time loop, reliving the same day over and over -- and that day always ended with the destruction of the Enterprise. Eventually they caught onto this and decided to program a message into Data's brain to be sent back into the rift on the next iteration, and hopefully help them avoid the collision that got them caught in the rift in the first place. During the next go-round, the number three continually appeared throughout the day (Data was subconsciously repeating the pattern) until the time of the collision came again. Left with two choices about how to avoid the accident (one suggested by Data, and one by Commander Riker), they noticed that three could refer to the number of rank insignia on Commander Riker's lapel. Therefore Riker's was the right idea, not Data's.
 * The main Power Trio of Kirk, Spock, and McCoy in the Original Series.
 * And to top it off in the grand finale of Enterprise has the three Enterprise Captains speaking the "these are the voyages" narration while the three Enterprises appear on the screen.
 * In Blackadder II, the title character seeks the help of a wise woman when he falls in love with his manservant, 'Bob' (who, unbeknownst to Blackadder, is actually a girl in drag). She suggests three "cunning plans": first, he could kill Bob. When he rejects this she suggests he could kill himself, which he's no keener on. The third plan is to ensure nobody else ever finds out: "kill everybody in the whole world!"
 * In the episode "Major Star", Captain Blackadder gives Lieutenant George three rules to follow during his drag-date with General Melchett: 1) Never remove your wig. 2) Never say anything. 3) Don't get drunk and let him shag you on the veranda.
 * In the Lost episode "The Moth," Locke tells Charlie he will give him his heroin back only on the third time Charlie asks for it. On the DVD commentary, the writers and Dominic Monaghan joke that Charlie could have just said, "Give me my drugs, give me my drugs, give me my drugs."
 * Subverted (as is almost everything) on She Spies, Cassie and Shane each offer one possible, lightly humorous, explanation for an occurrence and then DD offers a third one, no funnier than the first three. The other two girls stare at her and she declares, "The third one doesn't always have to be funnier, you know!"
 * House has the episode Three Stories which is Exactly What It Says on the Tin although the stories begin to intertwine and House is trying his best to confuse the medical students about what story they are currently listening to.
 * In seasons 1-3, House's diagnostic team consisted of three members: Foreman, Cameron, and Chase.
 * Babylon 5 has this all over the place, especially in the case of the Minbari: Three castes, the ruling body consists of three individuals from every caste so 3 times 3, three languages, the most holy artifact is a triangle - and they have three of them)
 * Also, the Vorlon epigrams "Understanding is a three-edged sword" and "There are three sides to every question: your side, their side, and the truth"
 * While we're at it, the main climax of the show is the reveal that  Sheridan decides to Take a Third Option.
 * In the second episode of How I Met Your Mother ("Purple Giraffe"), Ted throws three consecutive parties because he wants to "casually" talk to Robin, who happens not to be able to come at the two first ones.
 * Charmed: "The power of three will set us free! The power of three will set us free! The power of thee will set us free!"
 * The Big Bang Theory: (knock knock knock) Penny! (knock knock knock) Penny! (knock knock knock) Penny!
 * (knock knock knock) Leonard and Penny! (knock knock knock) Leonard and Penny! (knock knock knock) Leonard and Penny!
 * Another The Big Bang Theory example, when Sheldon saved Leonard from a rocket fuel explosion in the elevator.

"Director Vance:...And the third?
 * Professional Wrestling is fond of this in some forms, ranging from the 'Triple Threat' match (3 fighters) to audience chants; one of the most popular is to match 3 syllables (e.g. 'R V D! R V D!' for Rob Van Dam). The other popular chant format? Four syllables and five claps ('You're a loser!' * * *** ), which adds up to nine.
 * Countless game shows have three contestants per episode. Jeopardy! and Wheel of Fortune are the best known.
 * Nearly every joke on Desperate Housewives follows this trope. All of Mary Alice's narratives will contain 3 examples followed by the main point.
 * The three presenters on Top Gear. This works well, as two of them can set up a pattern and the third can break it for humor.
 * Lampsaded on an episode of NCIS: McGee is saying reasons for something

McGee How did you know there was a third?

Director Vance: There is always a third."

"Deeks: Rule of Three. The third time will be hilarious."
 * And discussed on NCIS: Los Angeles, when Deeks makes the requisite "Gesundheit" joke after someone says a weird-sounding German name...twice, and the others all just stare at him.

"Vaughn: Hey. What's up, man? Hi, Bro."
 * Gilmore Girls: I wish my mom would let me have a car... or a bike... or my roller skates back.
 * Kamen Rider OOO has threes in everything. Three sets of three Core Medals per Greeed, three part forms for the hero, three part episode titles. The main characters themselves - Eiji, Ankh, and Hina - make up a trio. Each "Previously On..." segment gives us "These three things happened on the last Kamen Rider OOO. The Transformation Trinket is even threefold (medals, scanner, driver.)
 * In an early season of Walker, Texas Ranger, in the first episode of the season, Walker corners the bad guy at the end of the episode. The bad guy turns and faces Walker, assumes a "karate stance" and makes a "karate yell". Walker beats him up. In the next episode, different bad guy, same ending. In the third episode, same ending except just when you are saying "this is getting a bit old", Walker drops his shoulders, sighs and says "Not another karate guy."
 * Community has Britta's one-time boyfriend Vaughn, who always says hello three different ways.
 * Community has Britta's one-time boyfriend Vaughn, who always says hello three different ways.

"Freddie: "My mom thinks I'll choke on pills so she pounds them with a mallet and puts them in my fruit sauce."
 * This is then Lampshaded by the study group, who start to count his greetings on their fingers whenever they see him.
 * ICarly uses this extensively. In iSaved Your Life:

Spencer: "Fruit sauce?"

Freddie: "My mom thinks I'll choke on fruit so she pounds it with a mallet--"

Spencer: "Okay yeah, we get it."

Spencer: "What happened to those flowers?"

Mrs. Benson: "I soaked them in bleach and then pounded them with a mallet!""

"Dragon: Very well, little mortal, ask your two questions.
 * In iQuit iCarly, after Sam & Carly have been pulled inside the building, they burst into tears and Spencer turns them to face one another so that they hug, whilst Fleck & Dave do the same thing. Spencer & Freddie look at each other & shrug, before hugging
 * Wizard Of Earthsea: the wizard Ged knows the Dragon's true name and has Power over him.

Ged; Hey! Don't I get to ask three questions?

Dragon: Yes, you do. Now you have two questions left."


 * The 2nd Criminal Minds episode, "Compulsion", features a serial arsonist/murderer driven by an obsessive-compulsive disorder that forces her to repeat things in sets of three. When (pretty arbitrary) patterns of threes emerge around her it triggers her to start her next round of arson and murder.
 * The Trinity Killer in Dexter Season 4. 3 sets of kills spanning 30 years.
 * This was actually very prominent in The Sopranos. Junior superstitiously believes that it applies to real life, going so far as to hope that his old friend dies of cancer because . . . two of his friends have died of cancer already, and if a third meets the same fate, he'll be off the hook. Obviously cancer only targets three people of a given generation, right? It also plays into fan theories regarding the finale. Virtually every detail of the final scene evokes the number 3: there are 3 Sopranos at the table, there are 3 pictures on the wall, Meadow is able to successfully parallel park on her 3rd attempt. This brings Junior's "these things happen in 3s" theory to mind, suggesting that Tony really does die at the end to complete the trio that started with Bobby and Sil.
 * Double Subverted with Adult Swim. In 2009, they aired The Room for April Fools' Day. In 2010 and 2011 they did this again. Surely they're doing something different for 2012, right? Uh oh, their airing that movie aga--THEY BROUGHT BACK Toonami??? AWESOME!!
 * Lampshaded in Thirty Rock episode "Hey Baby, What's Wrong" by dr Leo Spaceman, after the second of three of Jenna's examples of what pressure means to her.

Magazine

 * PROTIP: A trio of characters from different games is a standard Game Pro cover.

Music
"[[spoiler:Attention all planets of the Solar Federation.
 * The Blue Man Group has kept itself to exactly three performers because it's the smallest group possible where you can have someone excluded from a majority somehow, a recurring factor used for a lot of their humor. (The Blue Men really only have individual personalities insofar as each one winds up doing several things -- the more oddball the better -- that cause the other two to look askance at him.)
 * Earth, Wind, and Fire.
 * Emerson, Lake and Palmer; Crosby, Stills and Nash; Peter, Paul and Mary...
 * The band The Early November (other bands have probably done this as well, but this is the only one I'm aware of) came out with a triple CD release, the collective name being The Mother, the Mechanic, and the Path.
 * Once upon a time, 3/4 time in music was considered the "perfect" time signature, and 4/4 was "imperfect." They were thus indicated with a circle (a perfect circle) and an incomplete circle, respectively. The former has passed into obscurity, but the latter has morphed into the lower-case C we know today. Averted nowadays; very few popular songs are ever in 3/4 time, and the "C" is commonly believed to stand for "common time."
 * Three chords is the stereotypical minimum for uninspired, bland pop/rock. Or, it could be intentional, "Three Chords and the Truth." Either way, you'll rarely see music with less, but plenty with just three.
 * Canadian musician Joel Plaskett has recently released a triple album called, fittingly "Three". It even has a lyric stating "good things come in threes."
 * Each disk has 9 tracks, for a total of 27. He also released an EP called "Three More", which contained...3 tracks.
 * AND most of the songs are in 3/4 time and contain lyrics and titles like "Rollin' Rollin' Rollin'", "Shine On, Shine On, Shine ON", etc.
 * "Knock Three Times" by Tony Orlando and Dawn.
 * Weezer has three self-titled albums, called Blue, Green, and Red by fans.
 * The ending of the 2112 Suite by Rush:

Attention all planets of the Solar Federation.

Attention all planets of the Solar Federation.

We have assumed control.

We have assumed control.

We have assumed control.]]"

"Three's my lucky number
 * Even Rush itself is an example (Geddy Lee, Alex Lifeson, Neil Peart)
 * Emerson Lake and Palmer had an album called Trilogy, though in a slight subversion it was their fourth album. However, it can be considered to have been their third if one ignores their Pictures at a Exhibition album, as many fans indeed do.
 * In "Coward of the County" performed by Kenny Rogers, Kenny tells the story of Tommy, a man who believes in Turn the Other Cheek. Tommy has a loved one named Becky. One day the Gatlin Boys come a callin' and subsequently take turns at Becky. Kenny makes it a point to tell you there was three of them.
 * The song "Threes" by Mercedes Lackey and Leslie Fish is built on this trope.
 * As is the song "Three" by Massive Attack.

And fortune comes in threes"

"You just have to see her
 * "Sometime Around Midnight" by The Airborne Toxic Event ends with a Rule of Five. This functions as a bit of Painting the Fourth Wall; the listener is expecting this trope to be in effect, and the fourth repetition surprises them, possibly even making them a little uncomfortable. In fact, they might think they misheard, until the fifth repetition underlines it. It might even be somewhat discomfiting. Which makes sense, as the singer is certainly disturbed.

You just have to see her

You just have to see her

You just have to see her

You just have to see her

You know that she'll break you in two"

"That's when the taxi man turned on the radio
 * Party In The USA by Miley Cyrus:

And a Jay-Z song was on

And the Jay-Z song was on

And the Jay-Z song was on"


 * Scherzo Tarantella -- It's ALL in triplet patterns.
 * Indian Classical music (both Carnatic and Hindustani) has a huge array of compositions in meters with 3 counts per beat, which are often light and lilting numbers, though some are also heavy numbers. In rhythmic finales, it is customary to repeat the ending sequences three times, with optional variations.
 * Folk music in India just adores triad rhythms.
 * Speaking of classical music, ever noticed how so many great concertos have three movements? Take your time, it's a BIG list.

Musical

 * In Animal Crackers, after the song "Hooray for Captain Spaulding," Spaulding tries three times to give his welcoming address. The first two times, the chorus interrupts him with encores of "Hooray for Captain Spaulding." He interrupts his third attempt by singing it himself, then saying: "Well, somebody's got to do it."
 * Erronius in A Funny Thing Happened on the Way to the Forum is told to walk seven times around the seven hills of Rome. The first two times he re-enters and walks sloooooowly across the stage as the rest of the cast watch silently. The third time he gets run over during a chase scene.
 * From Rent: "Say something. Anything." "Test, one, two, three - " "Anything but that."
 * One of the musical themes in The Magic Flute, labeled "The Triple Chord," is three voicings of a B-flat major chord, each one repeated three times in a short-long-long pattern.
 * In The Mikado, Pooh-Bah gives a "toast with three times three" repeating the phrase "long life to you" three times. Most people who play the role ham the third time up even more than is called for in the script (which is quite a bit.)
 * In Sweeney Todd: The Demon Barber of Fleet Street, Todd teaches Mrs. Lovett a pound-three-times signal.
 * In Into the Woods, the Witch tells the Baker and his wife that they must bring her the items "before the chime of midnight in three days time" in order to break the spell.
 * In the Cirque Du Soleil show The Beatles LOVE a white VW bug appears several times. The third (or possibly fourth) and final time.
 * In The Music Man, the piano lesson scene begins with Amaryllis practicing the same passage three times, always ending on the same wrong note. Mrs. Paroo plays the right note for Amaryllis the first two times, and Marian enters to correct her third try.

Myth, Legend and Religion

 * Shows up all the time in religion:
 * Christianity does this so much that 333 is used by people being ostentatiously Christian:
 * The Bible: 3 days pass between Jesus dying and returning to Earth. In fact, whenever a number is mentioned in The Bible, it's usually 3, 7, 12, or 40.
 * "Jesus answered (Peter), Wilt thou lay down thy life for my sake? Verily, verily, I say unto thee, The cock shall not crow, till thou hast denied me thrice". - John 13:38
 * And then, after his resurrection, Jesus asks Peter three times if he loves him, extracting from Peter a promise to continue his work three times before he leaves him alone. This is often regarded as a symbolic reversal of Peter's thrice-denial of Jesus before his death. Also cf. the Fight Club example above.
 * The three Christian virtues: Faith, Hope, Love/Charity (Charity refers to agape or selfless love, as opposed to Eros as self-gratifying and/or sexual love).
 * Also, although the only reference to this event in the Gospels states that Jesus was placed "in a manger, because there was no room for them at the inn", Nativity plays tend to show two innkeepers telling Mary and Joseph to go elsewhere because all the rooms are taken -- before a third also says that there are no rooms, but that Mary and Joseph may use the stable, since Mary is pregnant.
 * The Gospel of Matthew, the only one that mentions the Wise Men or Magi, doesn't specifically state that there were three of them, only that they came "from the East". The gospel does mention that they presented Jesus with three symbolic gifts; gold (signifying Christ the King), frankincense (representing Jesus' divinity) and myrrh (an embalming incense, indicating that Jesus would die to save God's people).
 * When Jesus fasted in the desert, he was tempted three times by the Devil; 1) Turn the stones into bread, 2) Throw yourself from this cliff and let God save you, and 3) swear loyalty to me and the kingdoms of the world will be yours.
 * The Trinity: Father, Son and Holy Spirit. The first sometimes is represented by an eye set in a triangle.
 * The Kyrie: Lord have mercy. Christ have mercy. Lord have mercy upon us.
 * Wicca has the "rule of 3", meaning (depending on who you ask) that everything you send out into the world either returns to you thrice as strong in consequence, or comes back to you on the astral, mental and physical planes. Furthermore, when casting a Sacred Circle in Wicca, the typical procedure is to walk around the circle three times and say the incantation three times. (In some practices anyway.)
 * This pops up occasionally in Judaism, though generally not as centrally as in Wicca:
 * The world is sustained by worship, study and deeds of lovingkindness.
 * These temper judgment's severe decree: prayer, repentance and charity.
 * In Kabbalah, the Tree of Life has 3 pillars: The pillar of rigor, the pillar of mercy, the pillar of balance.
 * Examples from Speak of the Devil include Pazuzu and Bloody Mary.
 * Some religions divide reality into Heaven, Earth and Hell.
 * For the Norse, the universe was divided into nine (thrice three) worlds on three levels: the upper level had Alfheim (elves), Asgard (war gods and those who died in battle), and Vanaheim (fertility gods). The middle level has Midgard (humans), Jotunheim (giants), Svartalfheim (dark elves), and Nidavellir (dwarves). The bottom level has Niflheim (those who died of disease) and Muspell (fire demons).
 * Mormonism recognizes three heavens/kingdoms of glory after the Final Judgement: The Celestial Kingdom (itself divided into three kingdoms), the Terrestrial Kingdom, and the Telestial Kingdom.
 * Subverted in Lakota mythology: Three is the number of imperfection, while four, far from its other implications, is the number of perfection.
 * Hinduism : Three gunas (modes) of nature : goodness, passion and ignorance.
 * Lust, Anger and Greed -- 3 gates to hell. Also gross, subtle and spiritual existence.

Radio

 * The character of Errol in The BBC series 15 Storeys High always answers a question truthfully, if asked it three times.

Tabletop Games

 * Rather than using it as a trope, the Dungeons and Dragons setting Planescape and its video game spinoff Planescape: Torment explicitly mention the Rule of Three in-story as a principle with cosmic validity. (Everything involves the number 3 somehow. There are even three cosmic principles.) Since the world(s) of Planescape are shaped by belief, it's not impossible that that's true. If enough people believe it's nonsense, it won't be...
 * There are enough Flat Earth Atheists like Morte to disbelieve it, yet the rule persists for the reason that Morte gives, that minds have a tendency to create patterns. This tendency is perhaps stronger than belief, which is why the rule can be widely debunked yet the evidence of it still appears.
 * One NPC adopts this principle and runs with it clear off the field. Calling himself "Rule of Three," he's an information broker who requires things in sets of three as his payment, and gives three true answers to any question. As a second character is known to associate with another of the three cosmic principles, it's suspected a third is out there somewhere as well, because... well, Rule of Three.
 * In the Living Greyhawk campaign, a magic item spoke three prophesies of destruction that the players could attempt to prevent.
 * Almost subverted in the fact that the original editor was only going to let the item speak twice, because the Big Bad had already received the first prophesy. But, then a change in editors mandated that the audience is stupid.
 * White Wolf's Storyteller/Storytelling systems use the Rule of Three extensively: three sets of three attributes, usually physical (strength, dexterity, stamina), social (charisma, manipulation, appearance), and mental (intelligence, wits, perception), and three kinds of abilities (talents, skills and knowledges). The rest can vary depending of the individual games, but the Rule of Three is also prominent in several:
 * In the New World of Darkness the three attribute groups are divided in another way, each with three traits in it like the main groups; power (strength, intelligence, and presence), finesse (dexterity, wits, manipulation), and resistance (stamina, resolve, composure).
 * The demo for Changeling: The Lost has Blue Jenny, who.
 * In Mage: The Awakening, mage tradition dictates that a mage owes three favours to any mage who acquires their soul stone (a piece of their soul distilled into physical form for power).
 * In Old World of Darkness:
 * In Vampire: The Masquerade, each Clan has three favored Disciplines its members can learn more easily, and drinking the blood of one vampire three times, on three different nights, gives this vampire power over the drinker. Also, vampires have three virtues to fight their three different flavors of frenzy.
 * In Mage: The Ascension, the Resonance of a mage's magick is defined by three types of specific resonances: Dynamic, Entropic, and Static. This is linked to the cosmology of the Old World of Darkness (see below). Relatedly, they face three kinds of main foes: the Technocrats (linked to Stasis), the Nephandi (liked to Entropy) and the Marauders (linked to Dynamism).
 * In Changeling: The Dreaming, changelings can be of three general ages: childlings, wilders, and grumps. And since the setting is about mythos and fairytales, there are MANY occurrences of the Rule of Three.
 * Werewolf: The Apocalypse introduced the cosmology detailed below, and also gives players three major traits that determine their werewolf character's place in the Garou Nation and what Gifts they can learn: tribe, auspice, and breed. Werewolves, and most other shapeshifters, have three breeds.
 * Over the course of the various editions of the various games, a somewhat unified and coherent cosmology emerged, with three major entities or forces: the destructive Wyrm, the creative Wyld, and the stabilizing Weaver, none of which are inherently evil (all in all, it's similar to the hinduist Trimurti). They play a major role in Werewolf: The Apocalypse (where they first appeared) and Mage: The Ascension (the Tradition mages that players usually roleplay are, in a way, balancing the three against three kinds of extremists). Supplements that delved into the deeper aspects of the Triat (the common name used for the trinity of Wyrm, Weaver, and Wyld) would reveal that each of the three has three more specific aspects. The most well-known are the aspects of the Wyrm known as the Eater-of-Souls, the Beast-of-War, and the Defiler.
 * The Trinity Universe setting. Three games: Adventure!, Aberrant, and Aeon (later renamed Trinity). Three "classes" of character: paramorphs (or Daredevils), eximorphs (or Stalwarts) and psychomorphs (or Mesmerists). The actual mechanics show the same divisions as other Storyteller systems. Each stat doesn't have three skills though. But oh well.
 * Exalted, while using almost the same system as the Old World of Darkness, subverts expectations by running its setting on the number five instead. Indeed, that the Lunar Exalted use the Rule of Three anyway makes them stick out incongruously, though that is justified: they used to have five castes and so forth, but their long exposure to the Wyld (unshapable chaos outside Creation) has thrown them out of whack.
 * Magic the Gathering blocks are released in three sets. Furthermore, Wizards of the Coast have their own "rule of three" - the first set establishes core concepts and mechanics, the second set develops them further, and the third introduces some new twist. For example, the third set of the artifact-based block Mirrodin presented effects that produced or used all five colors of mana, the third set of the legendary-based block Kamigawa gave the Epic spells and rewarded large hand sizes, and the third set of the land-based block Zendikar introduced the massive and colorless Eldrazi.
 * The "One for Three" cycle of cards from the first core sets that cost one mana of it's color's mana type. Grating the caster 3 of something related to the color (Damage, Life, or most famously, card draw).
 * The "charm" cycle. One card does one of three things.
 * Dungeons and Dragons for special defences: Fortitude, Reflex, Will.
 * The physical stats: Strength, Dexterity, Constitution. The mental stats: Intelligence, Wisdom, Charisma.
 * The alignments: Lawful, Neutral, Chaotic, and Good, Neutral, Evil. Put together into the alignment spectrum and there are nine options.
 * Dogs in the Vineyard is geared for groups of about three PCs, and Three In Authority is one of the most powerful rituals against demons (a two-PC group can pull it off with help from the NPC town elder).
 * In Nomine has the three Realms, Corporeal, Ethereal and Celestial, which each have a type of Force associated with them, also there are three main types of supernatural beings, angels, demons, and ethereals.
 * In Dungeon, a boardgame published by TSR and developed by, among others, Gary Gygax, to open a door, you have to roll for it three times. After the third time, you can just go through.

Theater
"Cyrano (irritated): No, I have told you twice! Must I repeat?"
 * Cyrano De Bergerac: This trope is combined with and Department of Redundancy Department: The gratuitous repetition of a question or a gesture for three or more times are shown in the play:
 * Played for Laughs: At Act I Montfleury tries to say his lines four times, Cyrano orders him to disappear when Cyrano clap his hands the third time, the bore asks Cyrano three times if he has a protector. Lampshaded by Cyrano when he does not answer a three time:

"You all did see that on the Lupercal
 * Played for Drama: At Act II, Cyrano asks three times Roxana what she would do if Christian is not as eloquent as fair, she answers two times that being fair, he has to be eloquent, and the third time she invokes Driven to Suicide. At Act IV, Cyrano asks Roxane if she would love Christian, even if he would be ugly, three times. She answered yes every time.
 * In William Shakespeare's Julius Caesar, Marc Anthony speaks at Caesar's funeral:

I thrice presented him a kingly crown,

Which he did thrice refuse: was this ambition?"


 * During this speech, he also says "Brutus is an honorable man" three times. A fourth time he just says, "And sure he is an honorable man", by which time he's in full Sarcasm Mode.

Video Games
"G La DOS: Well, this is the part where he kills us.
 * MANY video games (especially Platform Games and Shoot Em Ups) give you three lives before it's Game Over for you.
 * Some platformers have it to where you must strike the enemy three times to finish the boss battle.
 * There's also the very common three-hit combo attack.
 * And let's not forget the three-star rating.
 * Zelda has the supreme Triforce: Power, Wisdom, Courage. Also the three Goddesses that go with it: Din, Nayru, and Farore.
 * Also three CDi games...maybe not.
 * Not only just Triforce, the Zelda games are littered with Three's: There are three Sacred Stones, three magical spells, three elemental arrows, three Provinces covered in twilight, three Fused Shadows to collect, three fairies to save, and three metals from which the Phantom Sword is formed, in addition to everything else listed.
 * Several bosses will go down after three sets of attacks from Link. King Dodongo, for instance, goes down after three bombs.
 * Link begins every game with 3 hearts.
 * Three days to save Termina. Each temple also had three boss fights: one to obtain the Hero's Bow or elemental arrow (of which there are three), one to obtain the Boss Key, and one to free the giant and end whatever curse had invaded the land.
 * The The Legend of Zelda Oracle Games were supposed to be three (the third game would have featured Farore), but the link system between three games was too complicated to implement, so...
 * Ever since The Legend of Zelda a Link To T He Past, there is almost always a twist that comes after three MacGuffins. Also since A Link to the Past, each dungeon contains three artifacts: a Map, a Compass, and a Big Key (which leads to a treasure usually needed to solve the dungeon).
 * Super Mario Bros.: Almost all bosses in non-RPG Mario games contain some relevence to three, be it the amount of hits it takes, or the phases it goes through, or a combination thereof.
 * There are also three parts to the Miracle Toadley Cure.
 * In Super Paper Mario, World 7 contains many mythological references, many of which invoke the Rule of Three.
 * Each world in Super Mario Bros 2 has three levels, except the last world (which only has two).
 * Super Mario Bros. 3 has threes hidden in various maps. One is three threes of coins in World 5-1. Also, the king of World 3 lives in Kyoto (where Nintendo's headquarters are).
 * The Three Trials in Monkey Island.
 * Dragon Age has three dragons. The Archdemon is the final boss; Flemeth and the High Dragon are optional.
 * In the Ultima series, the Virtues were organized in overlapping threes; three Virtues are based directly on one of three Principles, three were based on a combination of two Principles to form another trinity, and one Virtue is based on all three Principles. One Virtue stood as a Unity of the three groups of three.
 * The games themselves are organized into three trilogies. The first three are the Age of Darkness, when most of the land is filled with monsters and dominated by the evil Triad. The second three are the Age of Enlightenment, as Lord British cultivates civilization and an ethical foundation based on the Virtues; in this arc the Codex of Infinite Wisdom is first brought from the Void, and then returned to share with another civilization. The final trilogy, involving the Avatar's nemesis the Guardian is actually spread over five chapters, including VII Part 2 and Ultima Underworld II.
 * In the Ratchet and Clank series:
 * The first game, Ratchet & Clank:
 * Most of the planets have three paths, or two paths and a special area (gravity boots, hoverboard race, etc.)
 * The final boss fight has three phases.
 * Ratchet and Clank Going Commando
 * The Thug Leader of Thugs-4-Less must be defeated three times.
 * The final boss fight at the end of the game has three phases, but can be shorter if the player applies More Dakka.
 * Dr. Nefarious at the end of Ratchet and Clank Up Your Arsenal.
 * Planescape: Torment, as explained above under Tabletop RPG.
 * Max of Sam and Max correctly guesses the number of prophecies the Sea Chimps have thanks to the series' use of this trope, with heavy Lampshade Hanging.
 * An earlier example in Episode 103 where the duo is initially given 2 tasks to complete for the Toy Mafia. Immediately after Chuckles says "two things you must do for us." another mafia member alerts him of a new problem that has arisen, causing Chuckles to correct himself and gives the heroes three tasks.
 * Pokémon has this in spades. Generation I has Articuno, Zapdos, and Moltres. The second generation has Raikou, Entei, and Suicune. Generation III has Regirock, Regice, and Registeel, as well as Kyogre, Groudon, and Rayquaza. Generation IV gives us Dialga, Palkia, and Giratina as a trio, as well as Azelf, Uxie, and Mesprit. With the fifth generation around the corner, it's almost guaranteed that there will be another trio.
 * The maximum number of evolutionary stages for a single Pokémon is three (unless it branches, such as Eevee, who started out with three evolved forms. It now has seven.
 * The fifth generation has three trios: The Tao, Kami and Musketeer trios? The Musketeers have Keldeo throwing them off-- it's a trio if we're counting the elemental monkeys, though.
 * By the end of each generation, there are three non-remake games: Red, Blue, and Yellow in Generation I (in Japan, Yellow is the Trilogy Creep, because there's already Red, Green and Blue), Gold, Silver, and Crystal in Generation II, Ruby, Sapphire, and Emerald in Generation III, and Diamond, Pearl, and Platinum in Generation IV. And the third is always quite different.
 * There's also three starters in all games except for Yellow.
 * Commander Keen started as a trilogy, had another three episodes (a duology and a stand-alone adventure), and was going to have another trilogy before it got cancelled.
 * Wolfenstein 3D, Doom and Heretic each started out with three episodes. The latter two each have episodes consisting of nine (three squared) missions.
 * In Quake III Arena the Quad damage powerup, contrary to what the name would suggest, multiplies your damage by three.
 * In Scribblenauts, if you feed an animal something three times, it goes to sleep.
 * Some of the earlier games for the Sega Master System (such as "Safari Hunt", "Ghost House" or "My Hero") only had three levels each. The "fourth" level was usually the repeat of the first, but with stronger or faster enemies, the "fifth" level was the repeat of the second level, and so on, with the difficulty upped every time the three levels were completed.
 * The first Sonic the Hedgehog game and Sonic the Hedgehog CD had three acts per zone, and so did the five Sonic games released on the Game Gear.
 * In newer games, there are usually teams of three, shown in Sonic Adventure 2 with the Heroes (Sonic, Knuckles, and Tails) versus the Dark (Shadow, Rouge and Eggman). Further built upon with Sonic Heroes, where each team is a team of three: Team Sonic, Team Rose, Team Chaotix, and Team Dark (which is Shadow and Rogue again, but with E-123 Omega). Also another example is that Metal Sonic has three forms, his normal "hedgehog" form, then his Metal Madness (a gigantic metal dragon-ish form) and his final form, Metal Overlord.
 * Metroid is fond of this as well. Particularly the Prime sub-series, with three Temples in Echoes (and each of them requiring 3 Keys for full access), 3 Phazon-infested planets in Corruption, and the 3 alternate beams and 3 alternate visors in each game.
 * Sword of the Stars has three classes of FTL-capable starships, with each being thrice the length of the previous.
 * Jurassic Park: Trespasser has three different tribes of raptors. Also, the neurotoxin dart rifle in one level holds exactly three shots, which, if you take it all the way to the end of the level with you, is exactly how many shots to the head it needs to kill the T-Rex waiting for you.
 * In Ace Attorney series, a trial in the courthouse for a particular case can only last up to a maximum of 3 times before the judge passes the final verdict to the accused. In the "3rd" game "Trials and tribulations", the character Dahlia Hawthorne appeared exactly 3 times in the courthouse for 3 different cases as a witness before she is "permanently retired" for good. The main protagonist also faced Godot in a courthouse battle up to 3 cases in total. Lastly, Phoenix Wright was featured as the protagonist for 3 games in the Ace Attorney series.
 * Starcraft has three playable races.
 * Heavy Weapon gives you three lives per level, allows you to have a maximum of three Nukes and three levels of Deflector Shields, and you can upgrade your equipment to a maximum of three levels.
 * Portal 2 gives us this example:

Wheatley: 'Ello! This is the part where I kill you!

Chapter title shown: The Part Where He Kills You."


 * There's also the achievement, but it doesn't appear on subsequent playthroughs, making it three.
 * Shatterhand requires three alpha/beta powerups to activate the robot companions.
 * In the Bloodmoon expansion to The Elder Scrolls III Morrowind, you have to kill spriggans three times before they stay dead. Thankfully they don't retain this Healing Factor in Oblivion or Skyrim. Instead, in Oblivion they summon bears, and in Skyrim, they can heal themselves three times (falling back into the trope).
 * Jet Force Gemini: Three playable characters, each of them visits three planets and, in the third of them, they face a boss. They then go to Mizar's Palace for a first-time confrontation against the Big Bad. Afterwards, the trope is averted for the most part.
 * In Black and White, the Sailors' Quest involves the aforementioned sailors asking for three things by song: Wood, grain, and meat.
 * Some versions of Final Fantasy(VII, VIII and X2) give you three people per party.
 * Final Fantasy XI gives three early bosses called The Black Waltz, essentially three powerful Black Mages. After the third Waltz is defeated, Zidane comments that the name "Waltz" indicates that there won't be any more of them.
 * Kingdom Hearts generally gives you a three-person party of Sora, Donald and Goofy(Donald and Goofy can be replaced by other playable characters).
 * In the 101 Dalmatians side-quest in the first Kingdom Hearts game, 99 Dalmation puppies are found throughout the game hidden in chests. There are always three puppies in each chest, for a total of 33 chests.
 * World of Warcraft:
 * Three talent trees/specializations
 * Mists of Pandaria will buck the trend and give Druids four specializations
 * Three roles: Tank, Healer, Damage
 * Three kinds of pets: Cunning, Tenacity, Ferocity
 * Many, many 5-player instances feature three boss fights.
 * And if their entrances don't have a singular quest giver (who usually comes with two bodyguards), it's usually a group of three.

Web Comics
"Protoman: I suppose they're right, I can't take Mynd on my own...when did we start listening to Bass?
 * Triquetra Cats features three sisters taking up the mantle and war that their deceased mother was unable to finish.
 * From A Miracle of Science: Benjamin mentions that he spends much of his rare days off listening to classical music; he gives Bach, Prokofiev, and The Beatles as examples. (The webcomic's artist expounds on the Rule in his commentary.
 * In Eight Bit Theater
 * In Girl Genius, the third time Zola needs to be rescued when Agatha wants to talk to Gil, Agatha rescues her.
 * Also Jagers only get 3 tries to steal Old Man Death's hat.
 * MS Paint Adventures has this during the Problem Sleuth story. Three detectives, three dames, three gentlemen, three faces for DMK. Threes are everywhere in that story.
 * The latter entries in Bug tend to have one panel of set-up, followed by three more panels, each with a mini joke within them. "Random Thoughts" is a good example of this trope in action.
 * Bob and George With commentary explaining why two failures and a success make a good pattern. And again here.
 * Also, three strips in a row of thought bubbles when carrying out a plan hatched by Bass, all of which ended in them questioning the wisdom of taking tactical advice from the resident ditz. Summarised version:

Roll: Shame I never got to that relationship storyline...wait, when did we start listening to Bass? We're all going to die.

Bass: [pause] I like ice cream. [Pause] When did they start listening to me?"


 * Derelict The main character ponders them, related to survival: three minutes without air, three days without water, three months without food. Then she wonders if she got it right. (Not exactly: three weeks without food is the rule.)
 * Referred to by name in Zebra Girl, by Sam (being Dangerously Genre Savvy is his thing) as an explanation for why he smacked their new ally three times: once for trying to attack him, once for not immediately joining his side, and once for talking with his mouth full.

Web Original
"Simmons: Alright, let's run on three.
 * The Youtube Poop video Meet the Artillery by electricthecheese does this by having an overly-long-gag of Heavy Weapons Guy saying "GUN." After a while, there is a long, unedited period, and at the most unexpected moment, the Heavy makes a loud, virus-sounding noise and one of the Care Bears inexplicably pops in. Also, the Engineer introduces himself several times, and then the Heavy and Sniper introduce themselves as engineers as well.
 * Used straight, then lampshaded in Life in A Game. When Lollerskates assumes his final form during his Final Showdown with the heroes, all it takes is three shots to his incredibly obvious weakpoint to finish him, which the Master Chief calls him out on after his defeat. Then he teabags him.
 * Red vs. Blue's "Son of a bitch!" running gag is usually done in threes, occasionally twisted with Spanish-speaking robot Lopez's "Madre de dios," subtitled as "Son of a bitch!"
 * Also, when Simmons and Grif are facing down the tank in Season 1:

Grif: Wait, ON three, or one-two-three-THEN go?

Simmons: ON three, it's always faster to go on three! Okay ready, one. ..


 * Grif starts running*

Simmons: two. . . three! * turns around, sees Grif already far away* Oh, you backstabbing cockbite."

"Tic-Tacs! Bag of Dice! Some...third thing!"
 * In the 19 Nocturne Boulevard episode Sword Kvetch, Cael must face the evil wizard's three challenges. Why? Tradition!
 * Lampshaded in Episode 4 of Cracked TV (5 Things You Shouln't Be Able to Buy on eBay):

""All hail Stephen, king of the Lesbians!"
 * Played straight in Harry Partridge's Stephen the Lesbian.

"All hail Stephen, king of the Lesbians!"

"All hail Stephen King! *Beat* Of the Lesbians!"

"What-?""


 * Hewy in Hewys Animated Movie Reviews reviews Toy Story 3 for the third episode of his third season.
 * In Zero Punctuation, Yahtzee subverts this in his review of Just Cause. He uses the title as a joke the first two times, where on the third he simply comments "how should I know?"

Western Animation
"The Lobe: Freakazoid, why is it taking us so long to fall?
 * In My Little Pony Friendship Is Magic, the Cutie Mark Crusaders consist of three different types of ponies. Scootaloo is a pegasus, Applebloom is an earth pony, and Sweetie Belle is a unicorn. Their names are three syllables each, as well.
 * In one Tiny Toon Adventures short, a clown runs by in the background three times. After the third and final time near the end of the cartoon, Babs dryly explains he's "a Running Gag".
 * The plot of the episode is about Buster's quest to revive a joke he's driven into the ground (represented by a clown in a grave...morbid). The joke has this trope too: "A duck, a rabbit, and a pig go to a restaurant..."
 * In Transformers Armada, there are three legendarily strong weapons formed by the combination of three Mini-Cons apiece... Caused partly by the Merchandise-Driven nature of the series, as Mini-Cons were sold in teams of three.
 * Also, the Mini-Cons added a third unique group of transformers alongside the Autobots and Decepticons - as witness their unique emblem.
 * Triple Threat - Rail Racer! And the original Triple-Changers came in sets of 3, and the Unicron Trilogy (and Headmasters) tended to have 3-kid sidekick teams. Transformers is _mostly_ based around the number 2, though.
 * Lampshaded and Subverted in Duckman. While looking for suspects at a nightclub, Duckman says "Something bugs me. He's the third suspicious character we've talked to, and the third one is always guilty". The lights go out, shots are heard and when it's over the suspect is dead on the floor. Cornfed observes "So much for the Rule of Three."
 * In an Animaniacs short: "Tea? Coffee? Monster?"
 * Another example: Slappy is eulogizing her archfoe Walter Wolf, who was faking the funeral to 'get' her. According to Slappy, Walter was a firm believer in this rule, including three bombs that were found lying around to blow her up. 'I'm sure he'd want to be buried with it.'
 * Averted on Extreme Ghostbusters. "On the count of three." "Three!"
 * In one episode of Freakazoid, the titular character is picked up by a holographic pterodactyl and dropped from an extreme height, and he screams for help every time he falls. Lampshaded the third time when he and the Lobe fall together:

Freakazoid: Cuz it's funny!

The Lobe: No it's not, it's just stupid! It's as dumb as that Handman episode!"

""Sir, we have a security breach!"
 * South Park: "Biggie Smalls. Biggie Smalls. Biggie Smalls."
 * South Park also did it in the Imaginationland episode:

"What?!"

"There's an Unauthorized Entry Alert! It's coming from Sector Two!"

"Sector Two??""

"Spongebob: And no amount of mermaid magic...or managerial promotion...or some other third thing..."
 * Cartman then jumps in through a window. The second time the above dialogue occurs, Cartman again jumps in through the shoddily repaired window. The third time it happens, Kyle jumps in through the remnants of the window, causing the general to exclaim, "Why is it so easy for children to break into the Pentagon?!"
 * Also in the episode "Two Days Before the Day After Tomorrow" after Stan, Kyle, and Cartman leave, Randy volunteers to go after them, whereupon he is told "You can't go, you'll freeze to death!" whereupon Gerald volunteers to go, and is told "You can't go, you'll freeze to death!". Cue a third random person volunteering and a third random person reluctantly saying "You can't go, you'll freeze to death."
 * Schoolhouse Rock did a song about the 3's times tables. Hilariously, it was called Three Is a Magic Number. It was full of all kinds of examples.
 * This is all over the place in the Disney cartoons:
 * Oliver and Company: "Three sunrises. Three sunsets. Three days, Fagan."
 * The Little Mermaid: "Before the sun sets on the third day..."
 * Aladdin: "Now about those Three Wishes..." Also, it's three days (according to the Sultan) 'till Jasmine's birthday,
 * Also in Aladdin, there are three things the genie can't do: kill, force love, or raise the dead.
 * In Futurama: One spoonful calms you down, two spoonfuls help you sleep, but three spoonfuls, you'll go into a sleep and never wake up! Never!
 * On The Fairly Odd Parents, an episodes Running Gag is used three times. Also, in the "Wishology" trilogy, three wands were eventually needed to defeat The Darkness.
 * In the fourth season of Winx Club there are three eternal fairies that give the girls the three gifts of destiny.
 * Lampshaded in an episode of Drawn Together, when Wooldor describes what his television show will do. In his words, it will "Entertain kids, annoy adults, and funny third thing!"
 * Also lampshaded in the SpongeBob SquarePants Movie, during Spongebob's speech at the end of the film:

"Jay: (section 1, from 1988) Rain Man (section 2, from 1992) A Few Good Men (section 3, from 1993) The Firm (all together) is the latest stinker from Tom Cruise. He doesn't act anymore, he's on ... Cruise Control! AAAAAAHAHAHA! AAAAAAHA! I JUST ... I JUST! MADE THAT! UP!"
 * The Critic uses the same joke in this case: To prove to Jay that he's being repetitive, his boss Duke shows him a video of him hosting his show Coming Attractions, but with the screen split into thirds.


 * Examples from Speak of the Devil include the Freakazoid "Huggbees", Beetlejuice.
 * Combined with Inherently Funny Words in The PJs. Thurgood is working on a stand-up act and the book he got on how to be funny says things in three are funny as well as words with a hard k in them (like knish, tukas, fakakta). He logically assumes then that the funniest thing ever is KKK.
 * Family Guy uses this trope liberally for their gags. DVD Commentary also states the trope name for when a comedy uses a gag that involves three things.

Real Life

 * Body, Mind, Soul. Are the last two one and the same? Depends on whom you ask.
 * Birth, Life, Death.
 * Past, Present, Future.
 * Land, Sea, Sky.
 * Lithosphere, Atmosphere, Hydrosphere.
 * Breakfast, Lunch, Dinner.
 * Three primary colors.
 * Three point one four.
 * Who hasn't heard this? "Okay ready? On three..."
 * Survival's Rule of Threes for us untrained folk: Three seconds without blood(flow), three minutes without air, three hours without warmth, three days without water, three weeks without food.
 * Three months without love. You may think this is a joke, but it's not. People who become isolated, say from being shipwrecked, will go through a crisis about three months in. They may have all they need in terms of shelter, food and safety, but without fellow human beings, they're likely to stop caring for themselves, lay down and die. (A small proportion of people can live as hermits; they're the exception.) There's a reason Wilson was so important.
 * There is a saying "One time is chance, Two Times is a coincidence, Three times is suspicious" which suggests that 3 times is the least amount of times something has to happen before it is established as something more than coincidence.
 * In the UK, it's "once is happenstance, twice is coincidence, three times is enemy action". At least one James Bond story was built on this: Goldfinger, where Auric refers to this (the UK variant stated above) as being a phrase from Chicago.
 * In the UK, the school year is traditionally divided into three terms: Winter, Spring and Summer (or Michaelmas, Hilary, and Trinity (or even Michaelmas, Lent, and Easter) if you go to an old established school or university).
 * Same thing in India, except we just call it 1st Term, 2nd Term, and 3rd Term. There are also three big exams each year, known as end-of-term exams or simply term exams, and three sets of holidays following the end of each term. The third one is the big summer vacation, which marks the end of the school year.
 * Apparently the United States Marine Corps uses it too (albeit with the fire team level as an exception). This is referred to as "triangularization" and was adopted by everyone from the German Wehrmacht in the 1930s. Previously, it was the rule of fours.
 * The Rock, Paper, Scissors game (or Stone, Scissors, Paper, depending on where you are).
 * Or the Malay version, which uses bird, water, rock.
 * Look up any Weight Training routine, a vast majority of them will consist of each exercise being 3 sets of x reps, with 3 sets of 10 being the most popular.
 * Listing things in groups of three for emphasis is generally considered a useful technnique for giving a speech. One of the better examples was Tony Blair's declaration that his three priorities for government were, "Education! Education! Education!"
 * In the same vein, there's Stephen King's famous advice to wannabe writers: "Read, read, read! Write, write, write!"
 * Before that there was Danton's speech before the legislative assembly on September 2, 1792: "Gentlemen, what is needed is audacity, audacity again and audacity always, and France is saved." (Messieurs, il faut de l'audace, encore de l'audace et toujours de l'audace et la France est sauvée.)
 * And Count Raimondo Montecuccoli (1609-1681), who wrote that to wage war you need three things: Money, money and money.
 * The three most important things to remember about real estate purchases: "Location. Location. Location."
 * Ancient Jewish and Arabic custom allowed a man to divorce his wife by simply declaring 'I divorce you' three times. It has resulted in at least one incident where a man accidentally divorced his wife. (Or well, almost divorced her; turns out Islamic law, like any other half-decent legal system, does not allow you to make decisions like that while you're asleep.)
 * While not current in divorce, three is still important in Jewish court matters. The smallest size of a court is three (since it's the smallest plural odd number, meaning no ties). Also, Hataras Nedarim, a process done on Rosh Hashana Eve, involves collaring three friends who sit as a court and asking them that one's unfulfilled promises be annulled. The "court" repeats a small passage three times which effects the annulment. Similarly, a shorter version involves just saying the words "mutar lach" (you are released) three times. And there are three basic duties of a Jewish husband toward his wife - feeding her, providing her with cover, and satisfying her sexually.
 * In sports, there's the Triple Crown (horse racing), and the "hat trick" (various sports, all involving 3 of an action, usually but not exclusively scoring).
 * Also (in Baseball) the Hitting Triple Crown--highest batting average, most home runs, most runs batted in--and the Pitching triple crown: most wins, most strikeouts, lowest earned run average.
 * Baseball seems to run on this trope. Here are some examples:
 * 3 strikes and you're out.
 * 3 outs per inning.
 * 3 bases plus home.
 * More than 3 balls is a walk.
 * Thrice 3 innings in a game (without extra innings due to a tie).
 * In Cricket there's the hatrick - 3 wickets, 3 consecutive balls.
 * In American football, any score on the free play after a touchdown is worth one third of the normal value.
 * Kinda sorta. A kick/PAT is considered something different from a normal Field Goal, and a 2-point conversion is considered distinct from an actual Touchdown. Partially, in that the players on both sides in the post-TD plays will usually be Special Teams/specialists, rather than the normal lineup, and they will normally not use the exact same plays used in other situations. Yardage is also irrelevant in these plays; it's either a score or nothing.
 * In basketball, the most points you can score with one basket is 3 points.
 * There's the triple-double, for getting 10 or more in any three stats: usually points, assists and rebounds. (Technically, more than triple is possible, but triple is the most commonly talked about "limit", since steals and blocks are difficult to get 10 or more of.)
 * In bowling, three consecutive strikes is called a "turkey", and it's possible to bowl three times in the tenth frame, if you score a strike or a spare.
 * The Roman orator Cicero often used trios of phrases when wanting emphasis in speeches. While he may not have initiated the habit, many, many admirers picked it up.
 * "Government of the People, by the people and for the people shall not perish from this earth". This trope is probably why it's usually quoted as "blood, sweat and tears."
 * As mentioned on The Other Wiki, Abraham Lincoln used the tricolon in more than one of his speeches, including the Gettysburg Address. "But, in a larger sense, we can not dedicate...we can not consecrate...we can not hallow this ground."
 * From the Declaration of Independence, "Life, Liberty and the Pursuit of Happiness" (borrowed from John Locke, who used "Life, Liberty and Property")
 * And the French Liberté, Egalité, Fraternité...
 * And the German Einigkeit und Recht und Freiheit (Unity and Justice and Freedom).
 * From a more... troubled... time in German history: "Ein Volk, ein Reich, ein Führer". (One people, one empire, one leader.)
 * Which may owe something to a slogan from the French ancien régime: "Un roi, une loi, une foi." (One king, one law, one faith.)
 * From an earlier time in German history: Kinder, Küche, Kirche (the proper concerns of women: children, kitchen, and the church)
 * Lotsa "Three Strike" systems when it comes to rules in general. Two warnings, and the third time is when the proverbial poop hits the fan.
 * There are lots of threes in the human body: Three bones in the ear (hammer, anvil, and stirrup), three types of muscle (smooth, skeletal, and cardiac), three layers in the skin (epidermis, dermis, and subcutis), three types of blood cells (white, red, and platelets), hair can be divided into three parts (bulb, root, shaft)... Also, all organ systems arise from one of three primary germ layers in embryonic development -- the ectoderm, the mesoderm, and the endoderm.
 * Related: insect anatomy - head, thorax, abdomen.
 * In mathematics, there are three basic ways to approach a problem: graphically, numerically and algebraically. (This is sometimes even called the Rule of Three.)
 * The saying 'Third time lucky!' -Which is the idea that if you fail twice, you will succeed the third time, not that it's actually true. It's also heard as "Third time's the charm!" in America.
 * Sex, Drugs, and Rock and Roll.
 * The powers of a State, are comonly divided in: Judicial, Executive and Legislative
 * Several of the US space shuttle orbiter's systems are triply redundant, notably the Space Shuttle Main Engines, the fuel cells which generate electricity, and the auxiliary power units which provide hydraulic pressure to manipulate the orbiter's aerosurfaces and gimbal the three main engines.
 * The signal for Help in Morse code consists of three letters (SOS) and each letter is comprised of three dots or dashes.
 * Three somethings is a convention for a disaster signal: three fires, three gunshots, etc.
 * Next time someone comes to your door, see if they knock in groups of three.
 * Medical schools operate on the principle of "first you watch a procedure, then you perform it, then you teach someone to do it".
 * The three kinds of science: Life, Physical, and Earth. And then social...
 * There are three kinds of tectonic plate boundaries; convergent, divergent and transform. Within that, there are three kinds of convergent boundaries as well.
 * The Mozambique Drill follows this for close quarters combat. Two quick shots to the torso, followed by a slower and more well-aimed headshot to stop the target.
 * In Athenian democracy, Kleisthenes created a new kind of subdivision of the city's territory and free population called the phylai in order to create a stronger sense of belonging together. Each phyla consisted of a district of the city of Athens, one of the coastal and harbour region, and one of the inland agricultural region, Attica.
 * In many pre-modern Europe that part of society that had the right to participate in government (legislature) in some form was usually divided into three estates - clergy, nobility, and the rest.
 * Appears quite a bit in the United States Constitution. First, there are classes of senators. Three of them. Senators of each class are elected on different election years (but always even years, unless a senator dies in office). (For the record, should a fifty-first state be added, its senators would be in the first and second classes.) There are also nine Supreme Court Justices.
 * It's taught as a rule of drafting in some law schools on the basis that it emphasis that you are covering everything relating to a particular topic. For example a costs indemnity will often read "[Party A] will indemnify, reimburse and hold harmless [Party B] against any losses, costs or expenses [Party B] may incur, suffer or bear..."
 * In C++ programming, it is considered poor practice to define a destructor, copy constructor, or copy assignment operator without assigning the other two; this is actually called the "rule of three" in the thrilling world of C++ jargon. The reason for this is that the compiler usually creates these functions automatically, and the only reason that the programmer should define one is also the reason to define the others.
 * This Youtube video.
 * Research into short term memory has in fact determined that memorizing in groups of three is the easiest among all combinations.
 * Groups of three supposedly have some kind of special significance in Russian culture...allegedly because during Soviet times when things were cheaper if three men each contribute a rouble they could buy a handle of vodka to share and then have exactly enough kopeks left over for zakuski. (Ok, not quite as noble as the French or German examples, but practical..)
 * "Leaves of three, let it be." for avoiding poison ivy.
 * And poison oak. Also, poison sumac.
 * Franz Boas defined three types of anthropology: Ethnology, physical anthropology, and linguistics. Archaeology was folded into anthropology later.
 * In computer engineering, there's this: if a CPU encounters an exception, it calls an exception handler routine. If the handler encounters an exception itself, the CPU calls a special handler. But if the special handler too encounters an exception (such as the interrupt descriptor table being corrupt, making it impossible to call any handlers), that's called a triple fault and the CPU shuts itself down. Some kernels like Linux use it as a last resort in case the PC goes completely bonkers: if an ACPI reboot fails, the kernel sets the IDT length to zero, making the table impossible to access and intentionally triple-faulting the CPU. Not exactly to spec but it works.
 * Attempted and failed by Rick Perry during the Republican Presidential Debate of November 9th, 2011. Governor Perry said that as president, he would eliminate three government agencies: "Commerce, Education, and the-um, uh what's the third one there? Let's see..."
 * Quantum Chromodynamics states that each quark, the elementary particles of which hadrons are made, carries an electric charge which is a multiple of a third of the elementary charge; that each quark is one of three 'colours'; that quarks, like all elementary particles, come in three families; and much of a quark's characteristics is based on a unitary group, a mathematical construct, called SU(3).
 * Older Than Feudalism: In Ancient Rome, many legal matters were performed by simply stating what you were doing three times in front of witnesses, i.e. if you were marrying someone, you would say "I marry you" three times.
 * At the beginning of World War 2, RAF fighters generally operated in groups of three. However it was discovered that in combat one pilot would become separated from the other two and fall easy prey to enemy fighters. They then adopted the Luftwaffe's system of groups of four which in combat could easily sub-divide into two groups of two.
 * Internet Explorer, Chrome, Firefox.
 * When challenging someone to recite a Tongue-Twister, it's common to dare them to say it three times fast.
 * One that's pretty famous; Veni, Vidi, Vici. I came, I saw, I conquered.
 * A killer isn't considered a Serial Killer until after they have killed 3 people.