"X" Makes Anything Cool

"METAL SLUG! X!"

"'Blackmail' is such an ugly word, I prefer 'extortion'. The 'X' makes it sound cool."

— Bender, Futurama, "Anthology of Interest I"

X. There'x alwayx xomething about the letter X that juxt makex x-actly anything cool (including thix artixle). A lot of people use it gratuitouxly on a name, product, model, etx. juxt xo it has xome xort of edge to it, including xere. Want xome pizzazz? Add an X somewhere in txe name. It doexn't matter where, as long as there'x an X. And it hax to be a capital X. Lowercase x is juxt too puny to be xool. Juxt don't add three of them.

In order for this trope to work, though:

• The product isn't the 10th installment of a series that already used Roman numerals.
  • On the other hand, if the series goes 1, 2, 3, 4, 5, 6, 7, 8, 9, X...
• The X doesn't stand for a multiple of something. Example would be AMD's line of Athlon and Phenom processors: Athlon X2, Phenom X3, Phenom X4, etc, which don't count because the X indicates how much cores the CPU has; on the other hand, the FX line and the overclockable Ryzens that have an X after the model number do count.
• There's no real justification to use the X. Another letter would easily work if the X was a part of a word.
• If it's in the designation of a vehicle or other object, it can't be a prototype. In such cases it stands for experimental, and gets changed or removed when it enters full production.
  • Though it does add that extra bit of coolness to a Super Prototype, we admit.
• Similar to the above, the X in question is used as an abbreviation in an acronym for a word in English that has the ex- prefix, which would properly use E, but X looks cooler, of course. (Only a few English words begin with X, and most of those derive from Greek. The same holds for most European languages. Also, when starting a word with X in English, it's usually pronounced like "z" rather than like "ks".)

Subtrope of Xtreme Kool Letterz. For tropes that make use of this and when a work sequel adds the X after the original title, see Lettered Sequel. See also 4X, Let X Be the Unknown. Other tropes with the letter X include "X" Marks the Spot and "X" Marks the Hero. Not to be confused with [A Metasyntactic Variable as Portrayed in This Case by X] Makes Anything Cool.

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X-amples:

Anime and Manga X

• Bleach:
  • The "Lost Agent" arc deals with an organization called Xcution.
  • Lille Barro of the Vandenreich has an ability called "The X-Axis", one of the most powerful abilities seen among the Schrift and outside of it, and he is an expert sniper with heavy angel motifs.
• The titular character from B't X is a mechanical kirin, famous for being the most powerful battler of the villainous Machine Empire. Fortunately, he decides to help the hero...
• Cannon God Exaxxion has not one, but three Xs. They explain later that the XXX marks that are stamped all over the title robot aren't really Xs at all, but rather the last letter of the alphabet used by the aliens who created it. XXX is their generic symbol for an antimatter reactor, as the letter has similar connotations to the Greek letter Omega.
• DARLING in the FRANXX, which along with double Xs in the mechas of the title, also has the villains, the Klaxxosaurs.
• Halfway through Digimon Adventure 02, the main hero Digimon, V-mon (Veemon), finally gets a proper digivolved form of his own, a taller, buffed version of himself called XV-mon (ExVeemon).
• Gundam:
  • Gundam X, though it didn't quite work...
    • Justified, though, in that the titular Gundam's wing binders open up in the shape of an X when it deploys its Satellite Cannon.
• ∀ Gundam gives us the Turn-X Gundam. Whose name doesn't make a lick of sense, but the thing is awesome and deadly!
• The Yuri manga Hayate × Blade (where the X is pronounced "cross").
• The Lyrical Nanoha franchise gave us StrikerS Sound Stage X. Confused some people into thinking that this was the tenth Sound Stage (it was the eleventh, excluding the Megami Sound Stages). The X stands for the Mysterious Waif.
• Mysterious Girlfriend X. Extra strange because the X doesn't seem to mean anything (the "mysterious girlfriend" has an actual name).
• The working title for Pokémon 2000 movie was Pokémon X, and in fact there is a faint X shape in the final version poster/cover of the Japanese version. This also explains why Lugia is referred to as "Mystery Pokémon X" in a Johto miniarc in the anime.
• RahXephon.
• Romeo × Juliet, where the X is still intended to be pronounced "and".
• The anime adaptation of Rurouni Kenshin has two English dubs. One of them leaves the title unchanged, while the other renames the show Samurai X.
• Speed Racer has Racer X. Who later named a child "X".
• Sonic X, but we all know that Sonic is cool anyway.
• Transformers:
  • This is the basis behind the name of X-Brawn in Transformers: Robots in Disguise. It was for a while thought that X-Brawn was used because Hasbro couldn't secure a trademark on "Brawn", but one of their marketers later explained that they just put in the X to look cool.
  • Planet X in Transformers: Cybertron.
• X/1999, an anime made by CLAMP. Then they went overboard and came up with ×××HOLiC... (The xxx is silent, it denotes a variable in Japanese. The English pronunciation would be ___holic.)
• This trope is the most probable reason for 4Kids deciding to pronounce the previously silent X in Yu-Gi-Oh! ZEXAL for the English dub.
• In Zoids: New Century, Ultimate X is the name given to exceptionally powerful Zoids with an integrated Black Box/Organoid System.

Comic Books X

• Comic artist Frank Granados goes by "Franx Granados" (or just "Franx").
• The Guardians of the Galaxy's Groot comes from Planet X. He was invented in Marvel's 1950's monster comics, where the name "Planet X" was actually recycled a few times, but the name seems to have stuck in his case.
• In the crossover Mighty Morphin Power Rangers/Teenage Mutant Ninja Turtles, the second volume gives Casey Jones Ranger powers as Ranger X. It turns out to be a play on TMNT's Dimension X, as the dimension once had its own team of Rangers; with Casey, the Turtles, and April all inheriting the morphers and becoming X-Rangers.
• Wolverine:
  • Wolverine has a villain called Mister X.
  • And of course Wolverine himself is Weapon X. (These days, it's the Roman numeral, making him the tenth weapon created by the Super-Soldier project. Captain America is Weapon I. But that's a retcon created recently in the scheme of things.)
  • Then there's Wolverine's Opposite-Sex Clone X-23, who was made by a follow-up Weapon X program and is often called "X" by her friends.
• X-Men: Speaking of Wolverine, there's the X-Men as a whole. Because ex-men just doesn't sound cool enough.
  • But for some reason, Ex-Mutants was...or maybe not.
  • Stan Lee wanted to call it "The Mutants," but Executive Meddling (this was The '60s, he wasn't an executive yet) prevailed. He was told that nobody would know what a mutant was. "But they would know what an "X-Man" is?" fell on deaf ears.
  • The X-Men's leader, Charles "Professor X" Xavier. There is, however, an excuse apart from having an X on the name: it's a fairly common Spanish name, a latinized form of the Basque name "Etxeberri", which can be spelled "Javier" or "Xavier". "Javier" is much more common in real life, but "Xavier" has the much-coveted X while also being just as correct and legitimate (and is even the local spelling in neighboring France and Portugal).
  • X-Men spinoffs have driven this so far into the ground it's punched right through the planet. X-Treme X-Men being the ultimate offender.
    • Not to mention peripheral X-character "Adam X the X-Treme." Created in the heyday of the '90s Anti-Hero, he has that name and the power to ignite people's blood and possesses more spikes than actual bad guys on his costume in order to expose said blood to the air. Top it all off with a baseball cap worn backwards! Basically the living definition of "trying too hard." (Last seen setting The Juggernaut on fire, and then realizing that he'd set the Juggernaut on fire. Yeah, that could've gone better.)
    • X-Force #116 introduced the X-Statix, a Younger and Hipper group of mutants who are marketed in-universe as media superstars.
  • Moira MacTaggert's prisoner, the mysterious Mutant X, who turned out to be her son, AKA Proteus. The name was dusted off in the '90s for the comic book starring Havok trapped in a Parallel Universe, and an unrelated TV series Marvel had some hand in (Alphas is sort of a Spiritual Successor).

Fan Works X

• Harry Potter fanfic My Immortal features goffik band XBlakXTearX, featuring Serious Blak, Snap, Lucian Malfoy, and Jamez "Samoro" Potter. Notable for the fact that the latter once shot Lucan's arm off for playing a song wrong.
• Paper Mario X. The X stands for "crossover."
• A.A. Pessimal's Discworld:
  • Rodinian witch Xenia Galena runs into a little problem when her name is transliterated from Cyrillic to Morporkian script; in a place fairly recently beset by Gothic dreamers who set up a pseudo-coven of their own, nobody believes anyone can really have a name beginning with an X. Puzzled by older Witches patiently asking her what her real name is, she turns to a friend who has lived among these peculiar people and knows how their minds work. Irena Politeka explains to both sides.
  • A young Witch whose parents christened her "Xena" also has the same problem. Reluctantly, she trades in the "X" for a "Z" but people suspect that's a made-up "black lacy gloves with no fingers" sort of name too.
• This trope is all but explicitly stated in the Spider-Man/X-Men: Evolution crossover fic Spider-X, as Tabitha basically makes this observation when convincing Wanda to join her and Lance in defecting to the X-Men.
• One of the most popular Super Mario Bros. fan games has the title Super Mario Bros. X. After the original URL where the game was located, supermariobros.org, was purchased by Nintendo, the creators were able to get away with it by adding an X to it (supermariobrosx.org), also invoking this trope.

Films — Live-Action X

• The former MPAA rating X, now essentially synonymous with pornography.
  • "XXX", a porn industry marketing gimmick intended to imply something along the lines of "this movie is three times raunchier than an ordinary X".
  • And the less-desirable XX.
• American History X, particularly if you have Avery Brooks bark the phrase at the bratty teenager sitting in his office.
• The film A.X.L. is about a Robot Dog which is codenamed that. "A.X.L." actually stands for "Attack, Exploration, Logistics."
• Jason X, which also just happened to be the tenth movie in the Friday the 13th series.
• Julia X is about Serial-Killer Killer Julia, who has an "X" branded on her butt cheek by the Serial Killer known as the "the Brand Killer."
• The League of Extraordinary Gentlemen Film of the Book is acronymed LXG. Why? Just because.
• In the remake of The Longest Yard, Joey Battle (played by Bill Goldberg) has "X" as his uniform "number".
• Advertisements for Malcolm X often featured simply a lone "X" logo. This actually backfired a bit on them because you cannot trademark a letter, so the filmmakers could not claim a cut from knock-off merchandise.
• X-Wings in Star Wars are, like other crafts of the Rebel Alliance, named so because they look like that letter. This is interesting because the Star Wars universe uses the Aurebesh script, leading to the question why inhabitants of a galaxy "far, far away" should name their ships after Latin letters. Translation Convention, or just more Inexplicable Cultural Ties? Eventually it's retconned that a "High Galactic" script that's inexplicably identical to the Latin alphabet also exists in the Star Wars universe.
• Thunderbirds:
  • The spacecraft Zero-X in the first film, Thunderbirds Are GO. Not a prototype, this was the one intended for the first trip to Mars, until it failed during liftoff and exploded in the ocean. The replacement ship that launched two years later (2067) was also called Zero-X.
  • In the backstory of Captain Scarlet and the Mysterons, a third Zero-X mission was launched in 2068 (the second Zero-X also exploded), suggesting that the name refers to the spacecraft design, as well as with the only extant ship.
• xXx, starring Vin Diesel. xXx's real name is Xander Cage, so the xXx tattooed on his neck could be his initial repeated three times. However, after he steals an anti-game senator's sports car and drives it off a bridge so he can BASE jump off it in the opening scenes, Samuel L. Jackson's character suggests the three X's could also mean three "strikes" against the law. Jackson's character goes on to use 'XXX' as the name for the new task force he has created to bring together unconventional agents to battle dangerous threats.

Literature X

• Daniel X
• Discworld:
  • Agnes Nitt, a young woman, desperately tries to acquire some cool by (briefly) assuming the name Perdita X Dream, where "X" stands for "someone who has a cool and exciting middle name." Doesn't work though — all the people in her village refer to her as "the Agnes who calls herself Perditax."
  • In Unseen Academicals, we find that Dr. Hicks, the head of Post-Mortem Communications at Unseen University first introduced in Making Money, has started spelling his last name Hix because "a man who wears a black robe with nasty symbols on it and has a skull ring would be mad, or let us say even madder, to pass up the chance to have an X in his name."
  • The continent XXXX was originally a mapmaker's label, as in it was so unknown they didn't even know what a good name was for it. "Fourecks" actually became its name.^note XXXX is also the name of a well known Australian beer, pronounced Fourecks.
• In Craig Charles' The Log, he advises any heroes in a movie, when confronted with the villain's office full of filing cabinets, to go straight for the one labelled 'X'. "No evil mastermind has ever named his plan to Take Over the World 'Project W', guys."
• The SF trilogy by Ramez Naam: "Nexus", "Crux", "Apex". The second one even got a somewhat shoehorned Title Drop in the respective book, as if to say: "Hey, it's totally NOT this trope!"
• In The Pendragon Adventure, the biggest competition in Quillain's existence is the Grand X.
• The Echthroi in Madeleine L'Engle's book A Wind in the Door have the power to unmake elements of creation, a process referred to as Xing.

Live-Action TV X

• Disney XD, or "eXtremely Digital". That's right, little boys, Disney is cool now and totally not just for girls.
• Game of Thrones:
  • The Boltons seem to think so and this includes desecrated corpses! The saltire motif is prominently displayed on Bolton heraldry and paraphernalia, and represents the Saint Andrew's Cross-like torture frame that they bind their victims to. Even the Bolton forces' little figurine on Robb Stark's map has the screaming flayed man on an X-frame.
  • House Umber's sigil is four chains linked by a central ring on a dark red field.
• Kamen Rider:
  • The original Showa era had Kamen Riders X, ZX^note pronounced "Zet-Cross", and BLACK RX (the "RX" denoting an upgrade from Kamen Rider BLACK).
  • In Kamen Rider Agito, Kamen Rider G3 upgraded his Powered Armor to G3-X, "Generation-3 eXtension". Kamen Rider Gills also skirted this trope with the name of his Super Mode, Exceed Gills.
  • Kamen Rider 555 gave us Kaixa, whose motif is the Greek letter Kai (looks like an X, and his suit is covered with them).
  • Kamen Rider Kiva had Kamen Rider IXA, whose name is based on ikusa ("fighting", "battle", "war", etc.) but with an X. It's also an acroynm for "Intercept X Attacker", with X meaning "cross" — he's designed to be an interceptor going against attacking threats.
  • Kamen Rider W is normally themed around his name letter, but his Super Mode swaps it out for Xes as W Xtreme.
  • Kamen Rider OOO: As part of the show's 10th anniversary projects, Kamen Rider Birth gets a new Super Mode as Birth X, complete with X-emblazoned armor.
  • Kamen Rider Ex-Aid, short for "Extreme Aid" (he's a doctor, so it's presumably better than first aid). Besides just his name, he gets his powers from a Fictional Video Game series whose titles usually have an X or two on the end. The same series also has Kamen Rider Para-DX, which is "paradox" with Xtreme Kool Letterz.
  • In Kamen Rider Saber, both Kamen Riders Saber and Saikou get upgrades associated with Xes. For Saikou, he draws power from an American-style comic book called X-Swordman, and his armor in this form includes a large X on his chest. Meanwhile, Saber's Super Mode is named Xross Saber (pronounced "Cross", but with an X for coolness points).
  • In a tie-in movie for Kamen Rider Geats, Geats' Evil Knockoff is called Cross Geats as a pun on the cross fox, "cross" sounding like "kuro" ("black"), and importantly for this trope, it can be rendered "X Geats" as a play on Geats' own Super Mode Geats IX.
  • Kamen Rider Gotchard uses Cards of Power ranked from 1 to 10. The Rank 10 cards are heavily associated with Xes, incorporating them into the names and designs of the characters they depict, and Gotchard activates their power with an X-shaped add-on for his Transformation Trinket.
• Most Extreme Elimination Challenge or just MXC. Don't! Get! Eliminated!
• The TV show Wormhole X-Treme! within Stargate SG-1.
  Martin: Research says that shows with "X" in the name get higher ratings.
• Star Trek:
  • Starfleet designates experimental starships' line number with NX, instead of the usual NCC. Unfortunately, NX is changed to NCC as soon as the model enters common use.
  • In Star Trek: Enterprise, the "NX" designation is used for the entire class of starships that the Enerprise belongs to, as the Earth Starfleet operates under different conventions than the chronologically later series' Federation Starfleet.
  • Every proper noun in the language of Neelix's species, the Talaxians, contains an X somewhere.
• Super Sentai:
  • In Kaizoku Sentai Gokaiger, the Transformation Sequence includes three Xs (and a V) because Gokaiger is the 35th Super Sentai series.
  • In Kaitou Sentai Lupinranger VS Keisatsu Sentai Patranger, the Sixth Ranger has an X theme, with them on his helmet visor and mecha.
• Ultraman X puts the X on whatever it can find. Ultraman X himself has an X Chest Insignia, and was codenamed "X" because of it. He then doubles up on it with the name of his Super Mode, Exceed X. Heck, the Xio team Home Base is a giant building shaped like an X!
• Ultraseven X, released in conjunction with the 40th anniversary of Ultraseven.
• The X-Files:
  • The famous FBI department is called simply X-Files for no apparent reason. However, there is a really cool explanation which appeared on the show in season 5. They might have been called the U-Files for "unsolved" but weren't thanks to the filing system at the FBI in the 50's.
    Clerk Bahnsen: It's in an X-file.
    Agent Dales: An "X-file"?
    Clerk Bahnsen: Yes, unsolved cases. I file them under "X".
    Agent Dales: Why don't you file them under "U" for "unsolved"?
    Clerk Bahnsen: That's what I did until I ran out of room. Plenty of room in the "X"s.
  • Agent Mulder's second Mysterious Informant is known only as Mr. X.

Music X

• Brand X.
• Charlotte Aitchison's real name is a fairly clunky and unflattering one for a pop singer, so she took her MSN Messenger screen name, Charli XCX, and spiced it up a bit.
  "It stands for Kiss Charli Kiss, which is fucking lame. It used to be my handle on MSN Messenger. Then I got signed and thought, "Maybe I need to make it cooler," so I told the record label it stood for X-rated Cunt X-rated."
• DMX, named after the eponymous drum machine, and who often reduces his name to just X (i.e. "X Gon' Give It to Ya" and his debut album ... And Then There Was X).
• EXNLXDE.
• Gibson Guitar Corporation created the mixedly received Firebird X, an electric guitar with digital effects and other futuristic additions. Granted, the previous Firebird models are defined with roman numerals (Firebird I, II, III, V, VII, and XII) but there never was a VI, VIII, or IX. Neither was there XI, making the XII and X most probably this trope.
• Hardcore Punk and Metallic Hardcore bands (particularly those of the Straight Edge persuasion): X's drawn or tattooed on hands are common fashion and often incorporated into band names as well (examples include xDeathstarx, xTyrantx and xLooking Forwardx). The drawn or tattooed "x" seems to have stemmed from "all-ages" concerts, where the doorman would mark underage concert-goers' hands or wrists with an "X" so that bartenders would know not to serve them alcohol — in that context, it was likely chosen because it was just a simple and recognizable shape, but the fact that it's considered a "cool" letter probably also helped it to catch on as a symbol of straight edge.
• Industrial and EBM bands are fond of this trope. We have X-RX, X-Fusion (and [Sdrawkcab Name Noisuf-X]]), Studio-X, XP8, H.E.X.E., among others. Even bands that don't strictly fit this trope still make frequent use of Xtreme Kool Letterz.
• For Pentatonix, the group was originally going to be called "The Pentatonics", after the pentatonic scale. A friend suggested dropping the "The" and adding X at the end.
• Trap artist scarlxrd loves to replace "O"s with Xs.
• Borderline case: Charlie Sexton's second album, titled just "Charlie Sexton", with the "X" of his name red and x-tra large. Hey, theoretically he could have used any other letter than the X for that purpose, so it falls under this trope...
• Progressive metal group Symphony X.
• Progressive rock band Twelfth Night's 1986 album is sometimes listed as X, but that's actually a mistake. The cover features the band's name incorporated into what looks like a double-underlined X, but is actually the Roman numeral XII (for Twelfth) on its side. The album's actually called Twelfth Night.
• The Ur-Example is Los Angeles punk band X, led by John Doe and Exene Cervenka.
  • And the Australian band with the same name.
  • X Japan was also originally just named X. They had to change their name when they broke out of Japan because of the already well-established American X.
  • In the opposite direction, for a few years in the 1990s British band Bush was known as Bush X in Canada, because a Canadian band from the 1970s still owned the name there.
  • British group Liberty X added their X for similar reasons, after being formed from a TV talent show's runners-up as plain 'Liberty'. This was a permanent change, though, as the name was contested within the UK, rather than being a moniker-of-convenience temporarily adopted abroad.
• XTC. Doubles, of course, as a Pun on ecstasy.
• The xx, who also was originally named X before realizing that there were other bands with that name.
• Rapper and sometimes Riddick-antagonist Xzibit.
  • Don't overlook his signature song that goes "X! (untz-untz-untzuntz) X! (untz-cont'd)". Snoop Dogg is also featured in the ending:
    Mr. X-uberant, X-travagant, X-traordinary, X-citing, X-alotta.
    And what's the recipe? X-calibur weaponry, and we shoot them X-ceptionally.
    X marks the spot? Fuck not, X spots the marks. X-clamation point, niggas.
• The Post-Hardcore band XBXRX.

Pinball X

• Stern Pinball's Striker Xtreme combines this with Totally Radical.

Professional Wrestling X

• CHIKARA's Xyberhawx 2000, who are billed from "Xyberspace".
• D-Generation X
• When Shelton Benjamin worked in New Japan and Pro Wrestling NOAH in the 2010s, he was known as Shelton X Benjamin.
• TNA's X-Division, the Ultimate X match, and the pay per view Destination X.
• Short-lived, MTV-backed promotion Wrestling Society X.
• No better way to exemplify the trope than Vince Russo's early TNA stable "Sports Entertainment Xtreme", a typical Fun with Acronyms Russo idea.
• The seventeenth and eighteenth WrestleManias, called, respectively, WrestleMania X-Seven and WrestleMania X8.
• Then there was "X-Pac," derived from how he had been known as "Syxx" as a member of the New World Order in WCW in 1996-1997, and his gear sometimes featured the words "Syxx-Pac."

Radio X

• Radio stations in Mexico have call letters that begin with X. This was just an arbitrary assignment by the International Telecommunication Union, but it's very distinctive and memorable. Especially in the days of the "border blasters" and DJs like Wolfman Jack, the X carried a certain otherworldly, almost outlaw mystique, which ZZ Top celebrated in "Heard it on the X".
• Dimension X: The title relies on the imagination of alternate dimensions, these stories were all about the unknown; what is to come and how exciting it would be.
• Our Miss Brooks: "Project X" in the episode of the same name.
• X Minus One: The title comes from the countdown for a rocketship; "X minus five, minus four, minus three, minus two, X minus one...". The association is due to the emphasis on Science Fiction for this radio program.

Tabletop Games X

• While they haven't yet appeared in the show, the Yu-Gi-Oh! card game has the X-Sabers and their beefed-up cousins, the XX-Sabers.

Toys X

• The LEGO X-Pod line released in the mid-2000s.

Video Games X

• In the mid-90s, a reader of Electronic Gaming Monthly who noticed this phenomenon wrote a letter to the editors asking what the deal was. EGM responded with a sarcastic, dismissive remark, because at the time, EGM responded to every letter with a sarcastic, dismissive remark.
• The PSX... err, PS1 games 1Xtreme (originally titled ESPN Extreme Games), 2Xtreme, and 3Xtreme. Supposedly they are a combination of racing and eXtreme sports, as in rollerblades and skateboards.
• 4X strategy games. They should actually be Four E strategy games, but X is cooler.
• Ace Combat:
  • Ace Combat X: Skies of Deception
  • In Ace Combat 7: Skies Unknown, the enemy ace Mihaly A. Shilage is often called Mister X, overlapping with Let X Be the Unknown.
• The X-Strike Combination Attack in Chrono Trigger and its successor, Chrono Cross. The two participants each perform a Dash Attack against a single target, resulting in an X-shaped pattern. In Trigger, it's performed by Crono and Frog, and is useful against bosses in the early and midgame. In Cross, it's performed by Serge and Glenn, and is absurdly powerful, especially after both characters attain their respective Infinity+1 Swords.
• Clockwords: The letter X is the only one that has a damage level of five. Any words that have it can deal an impressive 25 damage.
• Command & Conquer: The First Decade has an X superimposed in the box art. Of course, it makes sense, but you know....
• DanceDanceRevolution:
  • DDR joined in the group of games with an X with Dance Dance Revolution X. Although there is some meaning to it as DDRX was released during the game's tenth anniversary.
  • Some of the MAX series of songs like to throw in an extra X: "MaxX Unlimited", "Fascination MAXX", and the supposed dummied song "MAX to the XXXimum".
  • Not to be confused, of course, with Revolution X, the only Arcade Game to run on Midway's "X-unit" board.
• Some skills in the Disgaea series have X-shaped areas of effect.
• Dottori-Kun uses up to 3 Xs as enemies.
• Final Fantasy:
  • Thanks to censorship in Final Fantasy on the NES, Kill was named XXXX. There's also the Warp/Banish spell, occasionally known as X-Zone as in Final Fantasy VI.
  • On the subject of the series, Final Fantasy X-2 probably counts as an aversion, as the "X" still stands for "ten", the game that X-2 is a direct sequel to. Yes, this means there are two layers of numbering on this game; what's your point?
• Playboy X, one of the main characters of Grand Theft Auto IV.
• Present in three of the Guilty Gear sequels (and their corresponding revisions): Guilty Gear X, XX, and Xrd (pronounced "Zex", "Igzex" and "Igzird", respectively).
• Guitar Hero, Rock Band, and Dance Central developer Harmonix.
• The Kingdom Hearts series loves this, overlapping with Let X Be the Unknown:
  • Every member of Organization XIII has an X in their names in a form of Theme Naming — their names are anagrams of their original names, plus an X. Some of these work fairly well like Dilan becoming Xaldin, but some like Axel just seemed to raise questions and eyebrows. Even when his real name was revealed to be the slightly feminine-looking Lea (pronounced "Lee" to mitigate that) in 358/2 Days. The exception is Xemnas, who stole the name Ansem before his transformation. His original self was named Xehanort, which, if the X is removed, can make "no heart" and "another" — or "no earth", given he steals the body of a guy named Terra.
  • There's also the χ-blade from Kingdom Hearts: Birth by Sleep. It's spelled like the actual Greek letter "chi", which makes it a Multiple Reference Pun and is the reason for the Organization's naming practices mentioned above. And its wielder can fire a Sword Beam, of course in the shape of an X.
  • Sora's new outfit in Dream Drop Distance features a silver X on his chest. It even carries over to his Tron Lines in The Grid. The same game also reveals that the X is formally known as the "Recusant's Sigil" — a mark that gives Xehanort the ability to seek down anyone marked with it. This is the reasoning for the Theme Naming above as well as why Naminé, being exempt from said Theme Naming, is able to hide from them during 358/2 Days and II.
• Klaxxon, so cool they x-ed it twice. (If not it wouldn't have been an example. In this case, the X is somewhat justified — can you imagine the game being titled "Horn" or "Siren"? — because you get extra points for making a big X in gameplay.)
• Atlus' fairly obscure Hack and Slash game Maken X is a twofer. The eponymous Maken is a sentient demon sword wielded by the game's heroine, while the "X" in the title can be chalked up to Rule of Cool. Then, when the game was ported from the Dreamcast to the PlayStation 2, it was retitled Maken Shao. Among other reasons, this is because there was already an "X" in the title (魔剣Ｘ), so the "爻" character^*"shao" in Cantonese used in the new title (魔剣爻) is meant to resemble a "XX".
• Mega Man:
  • Mega Man X. This may have caused confusion, as the American release used Roman numerals to denote the title while Japan used Arabic numbers. So to Japan, Mega Man X was just a name. To Americans, they might have thought this was the tenth Mega Man game (though this was Jossed long before the release of Mega Man 10). It helps that the titular Mega Man in this series is actually named "X" by Dr. Light, and, being a Super Prototype bot, the name was likely applied to signify his status as such.
    • The Angry Video Game Nerd mentioned it in his name confusion video.
    • Even Penny Arcade got it mixed up.
  • A later series goes even further: Mega Man ZX. It's very convenient that the characters Zero and X already have the naming conventions to set up the kool title. (And, in fact, the hero of the first ZX gets to use both of their powers together, hence the title.)
• Metal Slug X and Metal Slug XX, which were remakes of Metal Slug 2 and Metal Slug 7.
• In Metroid Fusion, the main antagonistic threat are alien parasites called the X Parasites, with the ability to Kill and Replace their prey. The X were so dangerous, the Chozo had to bioengineer their own predators, the eponymous Metroids, just to keep the population down, which would in turn lead to everything else in the series when villainous groups decided to use the Metroids as weapons.
• Microsoft Flight Simulator X, the tenth game in the series. All previous Flight Simulator games were named after the year they were released.
• The tenth Mortal Kombat game is called "Mortal Kombat X" (which is "ex" as in "next"...but also "10").
• In M.U.G.E.N, there is a modified, much more powerful and harder to beat version of Popeye the Sailor double-modified by ArthurDM and then DDR named Popeye X. The X was added to his name for no reason, aside from making the everyone's favourite already cool spinach-eating sailor sound even cooler. X-ellent x'cuse!
• Paper Mario: The Thousand-Year Door has the X-Nauts. And the X-Yux (supposedly pronounced "cross-yux"). Or just the Yux in general.
• When Phoenix Wright gets a cold, his favorite brand of cold medicine is called Cold Killer X. Note, this only applies to the localization. In the original Japanese version, it was called Cold Killer Z.
• The DSiWare game Photo Dojo, known as Photo Fighter X in Japan.
• Before its release, the code name of the first PlayStation was PS-X, short for PlayStation-eXperimental. (This is why you'll often see PS1 titles designated with "PSX" when mentioned.) Later, Sony released a digital video recorder with integrated PlayStation and PlayStation 2 hardware, called PSX.
• Pokémon:
  • Pokémon XD: Gale of Darkness falls under the "ex-prefix" exception, as XD stands for "eXtra Darkness" and "eXtra Dimension."
  • Pokémon X Version is a straighter example, although its counterpart being Pokémon Y Version means it depends on whether real-world X/Y pairings are a case of this trope.
• Progressbar 95: Progressbar 1X. It's the most cutting-edge system available, and the only one with a radial progressbar.
• Daniel Remar likes to use the Roman "X" instead of "10" in his games (such as Iji) for this reason.
• The Sega Genesis CDX was an all-in-one console that could play both cartridge and CD games, and also served as a (not very) portable audio CD player. The Genesis also had the 32X add-on.
• Splatoon 2 introduced an example of this to the Splatoon series' ever-expanding list of multiplayer ranks. First are the nine lettered ranks from Rank C- to Rank A+, then the even higher Rank S, and then the additional Rank S+, which itself contains ten numbered sub-ranks from S+0 to S+9... If one can climb their way through all of these, they will be awarded with the highest rank in the game, which contains roughly the top one percent of all players: Rank X.
• Street Fighter: The Japanese version of Super Street Fighter II Turbo is called Super Street Fighter II X (likely changed due to the fact that the letter X could be confused with the Roman numeral for ten). This is the reason why the letter "X" appears when a Super Combo is used in the Game Boy Advance version, as well as why the Super Turbo-like fighting style in Street Fighter Alpha 3 is called "X-ism".
• Super Smash Bros.: Super Smash Bros. Brawl is titled Dairantou! Smash Bros. X in Japan. Melee was also DX, short for "Deluxe."
• The final boss music from Touhou Hisoutensoku ~ Choudokyuu Ginyoru no Nazo o Oe is Unknown X, Unfound Adventure.
• The Tree of Life: The Chromosome layer is marked as X. Downplayed as it's likely named after the well-known X chromosome, and the letter C was taken by Cells, while two letters are reserved for sublayers.
• The TurboGrafx-16 and its successor PC-FX.
• Lampshaded in Vampire: The Masquerade - Bloodlines: If you ask him for life advice Smilin' Jack will mock any Player Character whose name contains an 'X' by claiming that you should never trust people with an 'X' in their name.
• The Japan-only Game Boy game X and its DSiWare sequel X-Scape
• The early online adapter for the Genesis and the SNES, the XBAND.
• X-Blades, for no real reason. It was originally called Oniblade, which would make this a case of Anime Makes Anything Cool.
• The Xbox line of game consoles is the highest profile example in all of video gaming. Its ancestor, the 8-bit MSX computer line, invoked this trope all the way back in the 1980s. Apparently the single X lost its luster, though, so they added another one for the 2017 and 2020 editions, the Xbox One X and Xbox Series X.
• X-COM. It stands for "eXtraterrestial COMbat unit". And sounds extremely cool.
• Egosoft's X-Universe, an entire series which gets its name from the player's ship in X: Beyond the Frontier: The Xperimental Shuttle.
• The sequel to Xenoblade Chronicles 1 is entitled Xenoblade Chronicles X. No explanation has yet been given for the X in the title, though until recently the codename for the game was just "X" before it was revealed to be a Xenoblade sequel.
• In Xenosaga, the character KOS-MOS (she's a robot... imagine that) has a development code of KP-X.
• Early 90s arcade shooter Xexex, which also has the benefit of being a palindrome.

Web Animation X

• Xeriouxly Forxe, the mock-Darker and Edgier version of Homestar Runner has a loose system for it: Generally, any 'S' sound is replaced with an X. The characterx have acknowledged the difficulty of xpeaking thix way.

Webcomics X

• In Charby the Vampirate Dr. Hayter left the Blackbox project for the mysterious Project X shortly before Menulis ate the two scientists he'd been working with on the project during a full moon.
• Well, Xykon from The Order of the Stick certainly thinks so. He chose the name Xykon for himself after meeting a man named Xavion who wanted to recruit him for his team of sorcerers, and thought the name "Xavion" sounded cool.
• xkcd. According to Word of God, it doesn't stand for anything, it's chosen to make it difficult to pronounce, and of course because it's cool. And yes, its official spelling is with all lowercase, or possibly all uppercase if that is not usable for some reason. Xkcd is "frowned upon".
• XWhy. Because x can be anything, and you'll know why.

Web Original X

• A certain very NSFW site URL begins with ex- (no triple x though) and directly cites the above Futurama quote. It's hit #45389 from 82600 if you ''have'' to Google.
• This trope is discussed during The Runaway Guys' Let's Play of Mario Party 4:
  Chuggaaconroy: Michael Bay wants to sound like even more of a badass guy so he's like "I am Michael Bay... X!"
• The YouTube 10-year Milestone Celebration video is an "A-to-Z". The word "experiments" is used for the X.
• The letter itself even has it's own subreddit. X-otic, ain't it?

Web Video X

• Auralnauts' fake commercial for an "X-Chair".

Western Animation X

• Protoform X in Beast Wars. Along with Cheetor's line that the pod was branded with "a big, bad-lookin' X!"
• The Ben 10 franchise has Alien X, Ben's Reality Warper form. In addition to highlighting his mysterious nature, it doubles as a Stealth Pun, as X is the Roman numeral for 10.
• Planet X in the Duck Dodgers cartoons. Later parodied in Duck Dodgers in the 24½th Century: they find Planet X by first searching for Planet A, followed by Planet B, followed by...
• Futurama has the Trope Namer in its episode Anthology of Interest I, who also manages to double as the Trope Namer for "Blackmail" Is Such an Ugly Word. See the citation above both pages.
• Johnny Test has Johnny X.
• The Modifyers has Agent Xero.
• The Pink Panther: The Inspector and Sgt. Deux Deux are out to apprehend a figure simply named "X" in the cartoon "Plastered In Paris." It turns out that X is actually the Interpol phys-ed coach and was giving the Inspector a workout.
• The Powerpuff Girls were brought to life and given their ultra-super powers via Chemical X. In one episode Mojo Jojo removes their powers using Antidote X.
• "X Agent" from Sheep in the Big City. The trope was parodied in his first appearance:
  General Specific: I don't want an "X Agent"! I want a current agent!
  Private Public: The "X" is put in to indicate mysteriousness rather than his job status sir.
  General Specific: Well why can't he choose another letter? Like "K"?
  Private Public: "K" isn't as mysterious a letter as "X", sir.
  General Specific: What about "L"? "L" is pretty mysterious! [waving fingers] Llllllllllllll...Lllllllll!!!
  Narrator: So, as General Specific re-acquaints himself with the alphabet...
• Dimension X from Teenage Mutant Ninja Turtles (1987), which is alternately described as a distant spiral galaxy or an alternate dimension.
• Teen Titans (2003) features a villain named Red X. Although he does utilise a variety of tools with an "X" motif, the design of the tools would entirely depend on the user's taste, so the trope still applies.

Computers X

• The operating system UNIX. Originally it was Unics, a pun on "Multics".
  • The X Window System for UNIX and Linux (which includes x-terminal, x-clock, x-eyes, etc). Justified—it's predecessor was "W" (as in windowing), which ran on the V operating system. 'X11', or even just 'X' also count.
• Microsoft seems to like this trope.
  • Back in the '80's, they made a version of Unix^note  A bit ironic since Windows is now pretty much the only commonly used OS that isn't Unix-derived, but that's beside the point which they called Xenix.
  • Early Microsoft Windows 1.01 for Tulip Computers OEM releases was called "1.xx", so the idea of using double Xs did not start with Xbox. The Zenith Z-100 release is also called 1.AX.
    • Microsoft refers various Windows 2.01, 2.11, 3.0, 3.1 and 3.11 releases as Windows 2.x and 3.x.
  • Windows XP. The XP stands for eXPerience, possibly because someone at Microsoft Central had been playing Dungeons & Dragons.
  • The cancelled version of Windows 10, the Windows 10X. ^note Originally announced for use on dual-screen devices such as the Surface Neo and other potential form factors, 10X featured a modified user interface designed around context specific interactions or "postures" on such devices, including a redesigned Start menu with no tiles, and use of container technology to run Win 32 software.
  • One of their 2-in-1 computers is called Surface Pro X.
  • Microsoft's "DirectX" and "ActiveX" APIs. What does the X convey about the product, exactly? ^{actual answer} The X is short for "Extensions". The Win32 GDI (the standard set of libraries used by Windows programs to perform graphics and input functionalities) proved too bulky and too slow to be used for games, having been designed instead to be a more general set of functionalities for application development. "Direct Extensions," or DirectX, was a library meant to simplify access to low level input/output hardware for graphics, input, sound, and networking. X for eXtension also applies to Intel's MMX instruction set. The other letters varied in meaning, or lack thereof, according to which side of the legal battlefield you were standing on. The X in this case is also the variable 'X', since DirectX is a collection of several different technologies, such as DirectSound, Direct3D, DirectDraw, etc., though most of those besides Direct3D have been deprecated so when people talk about DirectX nowadays they're usually referring to Direct3D.
  • The Xbox falls under this trope as well. Microsoft realized that "DirectX Box" just didn't sound all that catchy. The Xbox is, essentially, just a computer with streamlined DirectX support^note It's actually more complicated than that, as while the Xbox is an x86 machine, it deviates significantly from a run of the mill IBM compatible., one of the reasons why it and its successor are touted as being "developer friendly."
    • And of course, there's the Xbox One X. When not even two X'es are cool enough. Followed by the Xbox Series X (though that one has an alternate, the Series S).
  • That "XNA" is an example becomes clear once you realise what it stands for. XNA is a Recursive Acronym which stands for "XNA's Not Acronymed". So the only reason the first letter is XNA is X is because...XNA starts with X. Any other letter could be chosen to get the same result^note ANA = ANA's Not Acronymed, BNA = BNA's Not Acronymed, CNA = CNA's Not Acroymed etc., but they wouldn't be as cool as X.
  • Even the codenames aren't immune to the trope, as the available from Microsoft Connect is named Phoenix.
• XML (eXtensible Markup Language) and related standards, such as XHTML, XSL (including XSLT and XSL-FO), XForms, XPath, XQuery, XLink, XPointer, and so on.
  • On a side note, there's actually an older, unrelated XForms(a GUI toolkit), which is completely justified since it was ported from IrisGL to X11.
• Of course, hardware names can't be avoided either:
  • The XT, ATX, BTX, and DTX motherboard design standards. The X supposedly means X-Tended.
  • The PCI slot had an upgraded cousin, the PCI-X slot (again, meaning X-Tended).
    • When PCI-Express came about, people thought PCI-X meant that. PCI-Express's unofficial bbreviation is PCIe.
  • ATI/AMD and NVIDIA all have an X card.
    • For NVIDIA, up until 2014 the X moniker meant it was a high end card, usually marketed to gamers: the entry level card has no extra letter (in the GT 200 series it was the Geforce GT 210), the mid-range card had an S (e.g. GTS 250), and the high end card had the coveted X (e.g. GTX 280); this began to get pushed aside with the Geforce 900 series, which only uses the GT moniker for the lowest end card (like the GT 1030) and starts using the GTX moniker for anything even remotely mid-end like the GTX 1050 all the way to the GTX 1080 Ti. With the 20 series, Nvidia finally embraced the X by labeling all the models with an RTX, with the R standing for "ray-tracing". (However, they didn't replace the leading 9 with a leading Roman X — this was because they would otherwise not have the chance of selling a card with a designation that evoked the Full HD 1080p video standard).
    • ATI/AMD did this in 2005 when they jumped from the ATI Radeon 9000 series to the X300-X600 series, again in 2016 when they jumped from the AMD Radeon R7/9-300 series to the RX 400 series, then throughout 2017 with the RX 500 and RX Vega series, and their post-R5/7/9/X cards often get a slightly cheaper trim level with an X at the end of the model, e.g. the Radeon R7 260X. They eventually dropped the X in 2019 with the Radeon VII, but later returned to it two-fold with the announcement of the RX 5700 XT.
  • AMD's CPU division also uses the X moniker. Their old lineup of high performance processors was the FX series, the Ryzen series has an X that means they're overclock-ready unlike Intel's K (the AMD Ryzen R7 1800X is overclockable, like the Intel Core i7 7700K), and their chipsets also have an X at the end for the high end models.
  • The graphics card company XFX, which also slaps on XXX when one X isn't enough for their souped up graphics cards. So you end up with cards like the "XFX Radeon RX 580 XXX". (XFX thankfully held back with the Radeon RX 5700 XT, which would give a whopping total of seven X if it had a similar name, and called their high performance variant of that card "XFX RX 5700 XT THICC III ULTRA").
  • Intel uses XE for the "Extreme Edition" processors (it was formerly EE) and, with their part numbers sporting an X. Any high-end chipset also sports an X.
  • Intel also has the Xeon line of processors.
  • Corsair has its XMS brand of memory.
  • The codenames for the Xbox 360's processor and GPU are the Xenon and Xenos, respectively. The PlayStation 3's GPU is the RSX.
  • Creative Lab's X-Fi, for eXtreme Fidelity!
• And some actual computer models:
  • Dell's eXtreme Performance System, or XPS. EPS wouldn't be a great marketing name, would it? They also pretty much tacked it on to every computer they have
  • IBM PC-XT.
  • Apricot XEN.
  • The Commander X16.
    • They even discussed the trope. "so when Perifractic proposed the always cool "X" be added to make "X16" it got the team's vote."
  • NEC PC-98NX.
  • Sinclair ZX81 and it's more successful cousin, the ZX Spectrum.
  • Sharp X68000 and its predecessor X1.
    • As well as former's operating system SX-Window XVI and the music file MDX.
  • AmigaOne X series.
  • The prototype Commodore 64DX.
  • Gateway's high end laptops: FX.
  • Huawei MateBook X
  • Alienware has the M1#X and the ALX series of computers.
• Pixel, which stands for picture elements. Which one is kooler^note and easier to spell : 1280x768 picel, or 1280x768 pixel?
  • Works also as contraction of Pics Elements, Picsel - Pixel.
• ESX stands for Elastic Sky, apparently. (VMware server virtualization product.) X might have stood for the Greek letter chi.
• The Samsung Galaxy XCover series of Android smartphones.
• Products that for some reason go from version "9" into version "X". Roman numerals + Xtreme Kool Letterz = Rule of Cool.
  • Mac OS X. All previous versions were numbered using Arabic numbers.
  • Ditto for the iPhone X.
    • Apple's Department of Redundancy Department repeats the ten in the version number, so Snow Leopard is Mac OS X 10.6. Apple insists that the X is pronounced "ten," but usually inserts the word "version" between the two tens (eg. Mac OS X v'10.6). The page just linked is an ironic exception.^note As of version 10.11 (Sierra), the operating system is now known as macOS, for consistency with Apple's other systems (iOS, watchOS, tvOS). Up until this point, the operating system had been known simply as OS X.
  • The new version of QuickTime included with OS X Snow Leopard is so Xtreme that it skipped from version 7 to version X.
  • Paint Shop Pro, made by Jasc and then bought by Corel, originally used 1-8 for its version numbers. When Corel bought it, it went from 8 to IX. Then came X, then XI. As the switch happened with 9, not 10, one might be inclined to think this might not be a case of Xtreme Kool Letterz... until the 12th version came out as "X2".
  • Partly from superstition about the number 13, and partly so they could have cool letter in its name, the thirteenth version of Wordperfect Office is called X3. (And who is this WP Office owned by? Do we see a pattern here?)
  • Adobe in early 2011, released their tenth version of their PDF reader. They also invoked this trope by calling it Adobe Reader X.
    • Adobe then went on to release version eleven as Adobe Reader XI.
• The X.500 cryptography standards. Supposedly this is shorthand for Public Key Infrastructure, which is shortened to PKIX.
• Starting in 2016, Sony replaced its Xperia Z-series of phones with the Xperia X-series.
• Motorola's Moto X was the company's top-of-the-line smartphone from 2013 to 2016, when the failed Project Ara was salvaged into Motorola's new flagship model, the Moto Z. The Moto X line is still sold as a cheaper alternative to the Moto Z with similar hardware, albeit without the Moto Z's modular attachment system.
• Digital Equipment Corporation had "X" in the names of several of its processor architectures and computer systems:
  • In April 1975, the company announced it was rebranding its aging PDP-15 product line of 18-bit computers as XVM. In this case, "XV" obviously stood for the Roman numeral.
  • Also in 1975, engineers at DEC began developing a new 32-bit processor architecture to extend its successful PDP-11 line upward. The project name, VAX, stood for "Virtual Address eXtension" (the PDP-11's 16-bit virtual addresses limited it to addressing 64 kilobytes of main memory at once). According to one of the VAX's designers, the presence of the letter X was one reason why DEC chose to adopt it as the actual product name.
  • VAX was eventually succeeded by the Alpha AXP family of 64-bit RISC microprocessors, the last new processor architecture developed by DEC. "AXP" didn't officially stand for anything, though some insiders joked that it was "Almost eXactly PRISM" (PRISM being the project name of an earlier, unreleased RISC processor).
• Elon Musk thinks the letter X is extremely cool, and has incorporated it into several of his tech companies:
  • Banking company X.com, which later merged with a competitor to form PayPal.
  • SpaceX, short for Space Exploration Technologies Corporation.
  • Artificial intelligence company xAI in 2023.
  • Twitter was rebranded as "X" in 2023 following Musk's acquisition. In an inversion, most people consider the name change less cool, instead being kind of cliché and generic. It throws out the worldwide brand recognition of "Twitter" and "tweets" in favor of something untrademarkable and easily confused with the many other things out there that are named "X".
  • He's also named his children X Æ A-12 and Exa Dark Sideræl.

Others X

• Various car manufacturers attach an X somewhere in their car names.
  • The hatchback versions of the Honda Civic have an X attached at the end. DX and RX are their most common models.
  • From 2006 to 2014, the Toyota Corolla's sporty trim was called XRS and its logo was a huge X with a small RS. After 2014, it's simply a big red S. (2020 will see a revival of the old Corolla Levin name for the sporty trim).
    • Toyota's Scion make (2003-2016) had the xA and xB as its signature models.
  • Mazda's line of sports cars sport an X such as the Miata (MX-5) and the RX-7 and RX-8.
  • Ford has an XLT version of its F-150 line of trucks.
    • Not just the F-150... all of Ford's truck and van models (Maverick, Ranger, F-150, and Super Duty trucks; Transit Connect and Transit vans) have XL and XLT versions.
    • And for years Ford had a compact car called a "ZX_", peaking in 2005-06 when every USDM Focus model had such a designation (ZX3-3 door hatchback, ZX5-5 door hatchback, ZX4-sedan, ZXW-wagon).
  • Acura's compact hot-hatch is the RSX. Its three SUV models are the MDX, the RDX, and the ZDX. Its new entry level sedan is the ILX. And of course its sports car is the NSX.
    • The NSX is also a case of Let X Be the Unknown.
  • Nissan's Fairlady Z 300ZX, and 180SX/240SX (depends on where do you live).
  • Subaru SVX, XV, XT, RX and of course the Impreza WRX.
  • Citroën used this trope a lot between the 70s and Turn of the Millennium. Nearly every one of their passenger cars had the letter X in their names. Honourable mention goes to the Citroën ZX.
    • Their trim levels in the 90s were called X, SX, VSX and Exclusive.
    • And as if that wasn't enough, many of these cars were fitted with an XU-series engine.
  • Vespa mostly uses this straight, but inverts it in the LX series; The series was launched in 60th anniversary of the (Italian) company, and LX is Roman numerals for 60.
  • The very first car produced by Austrian motorcycle manufacturer KTM is the X-bow, pronounced "crossbow".
  • Tesla's Model X, of course.
• Julius Caesar's most trusted elite unit was the 10th legion, which in Latin had the full name Legio X Equestris. His successor Augustus later created the Legio X Fretensis after Caesar's famous legion, making this trope Older Than Feudalism. Both legions happened to become famous in history. The Equestris was one of the most important units in the conquest of Gaul. In the Year of Four Emperors, the commander of the Fretensis, which happened to fight a massive uprising in Judaea at the time, split his forces and put an end to the power struggle in Rome and became Emperor Vespasian, while at the same time his son Titus continued to fight the Jewish rebels. Titus led the still famous Siege of Masada and became the first son of an Emperor who succeeded his father to the throne. Later the legion was part of the army led by Trajan against the Persians, who also happened to become emperor.
  • Italian fascist government followed the Roman example by naming its elite naval commando unit X MAS (or 10th assault flotilla). They performed a number of daring missions against the Royal Navy in the Mediterranean, especially using saboteur divers (including the mining of battleships Valiant and Queen Elizabeth, which left the British Mediterranean Fleet without a battleship for about a full year).
• The U.S. military enjoys putting X in front of every eXperimental weapon name, along with the usual M. The XM16E, XM29, XM25, and XM8 are some recent examples (well not the XM16E).
  • All the experimental aircraft from the Bell X-1 (first supersonic aircraft) to the Grumman X-29 (forward-swept wings) — assuming they didn't skip numbers or that there aren't any others. Also, the XB-70 "Valkyrie" bomber as well as others.
• Out of all the letters in the alphabet to choose for the default variable in anything, why does "x" have to be it?
  • (an unknown) thing -> šay' (arabic) -> xei (Spanish) -> x (abbreviated). Now you know.
• X-rays: Because "Röentgen rays" just doesn't have the right sound to it. (Reportedly, Prof. Wilhelm Röntgen actually preferred the term "X" over his own name, despite the fact that he was was the one that discovered them.)
• Tokyo X, a breed of pig that is known for its quality meat...or a Japanese rock band.
• The EX-F1, an amateur-made rail gun.
• The short lived XFL, a particularly good example in that unlike some of the others, the X didn't stand for eXtreme—it was just an X.
• Malcolm Little, who became Malcolm X based on the practice of Nation of Islam converts rejecting their "slave names" and replacing their surnames with X until they earned a new name through a pilgrimage.
• David X. Cohen, a writer for Futurama. When he joined the Writer's Guild, he found his birth name, David S. Cohen, had already been taken, and the Guild has a strict "No Duplicate Names" rule for various legal reasons, so he chose the middle initial X because it sounded sci-fi. If asked what X stands for, he'll often say it just stands for X.
• Many people named Francis X., including the original Francis X. himself, St. Francis Xavier.
• Planet X, the name of a hypothetical planet in the far outer solar system. Not only sounded cool, but had the "X the unknown" thing and would also have been the 10th planet, this being before the discovery of the Kuiper belt and that business with Pluto.^note Actually, it's a bit more complicated than that. "Planet X" was meant to mean "unknown" initially, but would have been the ninth, rather than tenth, planet. When Pluto was found, they thought it was Planet X for years so the term basically disappeared. Then in 1978, they learned just how tiny Pluto was and realised that it couldn't have been Planet X. So Planet X came back, and was now the tenth planet. For about 15 years. In 1992, thanks to the Voyager 2 flyby, they learned that Neptune was a little lighter than initially thought, and so redid their calculations and realised they didn't need Planet X after all. In recent years, a theory that there may be a hypothetical ninth planet out there has resurfaced, but the Planet X name hasn't been resurrected for it, with this planet simply referred to as "Planet Nine" instead.
• Dubai Airport is written as DXB in all shortened forms such as on plane tickets and on arrivals timings.
  • LAX, i.e. Los Angeles?
  • Also PDX, i.e. Portland, Oregon. This has become identified with the city; notably, the web address for Portland State University is pdx.edu.
• Practically any time a word starting with "ex-" is shortened for an acronym, the letter X is used, instead of E. This has been particularly true for the word "extreme", which is so often shortened to "X-treme" that many usages don't need to explain themselves, such as the the X Games.
• "Christmas" is often abbreviated as "Xmas" in writing, as the Greek letter Chi, which looks like X, is the first letter of Xristos (Χρἰστος), Greek for "Christ". The "Chi-Rho", which looks like an "XP" in the Latin alphabet and usually written one on top of the other, was an ancient symbol for Christ- "chi rho" ("ch" "r") being the two first Greek letters of the word "Christ".
  • And also, X for "Cross", such as ped xing.
• Exxon. It doesn't mean anything, it doesn't stand for anything^note though it was a corruption of a prior name Esso, which came from the letters S.O., for Standard Oil, it was chosen because it was a) distinctive, b) not already trademarked, and c) sounded cool.
• JAXA: the Japan Aerospace eXploration Agency. Sounds a lot better than JAEA, doesn't it? And it doesn't hurt that it rhymes with NASA.
• On the stock market front, the Toronto Stock Exchange recently changed its initials from TSE to TSX for this simple reason.
• A giant, 40-foot Pliosaurus found in Svalbard was nicknamed "Predator X" until its formal description was released.
• A Norwegian 6-year-old forced his parents to deliver a letter he wrote to the King of Norway, asking for permission to change his name to Sonic X.
• The name Robert X. Cringely, well-known in tech circles, was entirely made up by InfoWorld magazine to provide some continuity for one of their columns, which would otherwise have been attributed to a string of short-lived writers. However, one Mark Stephens picked up the column and gained much fame with the Cringely name in the '90s. InfoWorld fired Stephens in 1995 and still has other writers filling in as "Cringely", but let him use the name outside of competing magazines as a settlement.
• Brazilian entrepreneur Eike Batista named all of his companies '**X' (EBX, MMX, OGX, MPX, LLX...), because he wanted to "multiply wealth". It eventually didn't work, but his point was valid.
• Axe Body Spray. They wanted a different name for its UK distribution, so they went with "Lynx," presumably by the time-honored method of "Are there any other short, manly-sounding words with X in them?"
• Sometimes, expressway name abbreviations are written in this way. One example is in Baltimore, where Interstate 83 terminates as the "Jones Falls Expressway" (JFX).
• ArXiv, the preprint server. (Formerly xxx.lanl.gov, a joke to get the site blocked. After the total success the joke became a bit counterproductive.)
• Six Flags Magic Mountain has a 4th Dimension roller coaster, formerly known as X. It was revamped in early 2008 and is now named X2.
• Amazon's speech assistent, "Alexa" is probably an aversion, as the hard "X" should make it easy to recognize in verbal commands, not as much or so much cool. (Also an allusion to the library of Alexandria.)
• Of all the countries in this very planet, only Luxembourg and Estados Unidos Mexicanos have the letter "x" in their names.
  • While the former's "x" is pronounced with a sound typical of many English language and French language "x" sounds, the latter has an "x" that sounds like the Spanish "j", which sounds like the English "h", in the non-Anglicized Spanish pronunciation. The original, non-Hispanicized form of the Nahuatl word, Mexihco, has the "x" pronounced like the English "sh" and is spelled with the letter "h".
  • The abbreviation of Ciudad de Mexico, the national capital ^note Complete with a federal district nonetheless. Other countries that have a national capital with a federal district include the United States of America, with Washington, DC, and the Federative Republic of Brazil, with Brasília. of the latter nation, is CDMX.
  • The original spelling of the Mexican state name, Jalisco, is Xalisco.
  • The USA state of Texas, originally part of same state along with Coahuila (which is still a Mexican state to this day) and Coahuila y Tejas, originally had the letter "x" in its name have the same sound as the Spanish "j," but has a typical English language "x" sound nowadays as the USA has English is its primary de facto language.^note  Neither the USA nor Mexico has official or de jure languages.
  • The Mexican states of Oaxaca and (Estado de) México have the letter "x" in their names pronounced the same as the non-Anglicized pronunciation of Mexico.
  • The USA state, and former Mexican state, of New Mexico ^note named after el Valle de México has the same pronunciation on the letter "x" as the Anglicized pronunciation of Mexico.
  • All twelve of the cities and towns in the USA called Mexico, with the largest and most prominent one being in Missouri, go by the Anglicized pronunciation of Mexico.
  • Xochimilco, the lake in Mexico City famous for its chinampas and trajineros, has an "x" sound sounding outright like an "s" sound.
  • The letter "x" is very prevalent in the Nahuatl language and the Maya language, both prominent languages in Mexico. In both languages, the letter "x" is typically pronounced with and "sh" sound.
  • OXXO, a chain of convenience stores very prevalent throughout Mexico, has a double "x" in its name and has an x sound like an "x" typical in the English language. The double "x,” the first "o," and the last "o," are supposed to symbolize a shopping cart.
• The Book of Barely Imagined Beings by Caspar Henderson. Showcases one interesting critter apiece from A to Z. Except two with X. Must be this trope. Or the author showing off. (Have you heard from Xenoglaux and Xenophyophore yet?)
• The logo of the Big 12 Conference in US college sports consists of a stylized Roman numeral "XII"... but the conference insists on being referred to in print as "Big 12", not "Big Twelve" or (shudder) "Big XII".
• In Lappeenranta, Finland, after receiving complaints by local residents, a transport company decided to change the "Z" route of its buses into "X", to avoid associations with the Russian invasion of Ukraine due to the Z letter being used in Russian propaganda.
• The fictional game Xoshi not only has a name that starts with an X, but the main character is also literally an X.
• The word "Thanks" is acronymed as "thx" in SMS, MMS, message boards, Internet forums etc.
• There's a fjord in Iceland named "Faxaflói".
• Even the name of the trope Xtreme Kool Letterz starts with an X, which why this very trope "x-ists".

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