->''"Chapters in books are usually given the cardinal numbers 1, 2, 3, 4, 5, 6 and so on. But I have decided to give my chapters prime numbers 2, 3, 5, 7, 11, 13 and so on because I like prime numbers."''
-->-- ''Literature/TheCuriousIncidentOfTheDogInTheNightTime''

Doing odd -- no, ''peculiar'' things with your chapter numbers. Which can be either odd or even. Or fractional. Or even stranger things, up to and including non-numeric. Or they can be put out of order -- counting down from, say, 10 to 1 is perhaps the simplest. Representing them with formulas, in binary, or in other non-standard formats works, too.

Compare IdiosyncraticEpisodeNaming, EpisodeZeroTheBeginning. Compare and contrast UnInstallment.

----
!!Examples:

[[foldercontrol]]

[[folder:Anime and Manga]]
* ''Manga/{{Bleach}}'': Some flashback chapters use negative chapter numbers:
** Chapter -0.8 covers the very first meeting between Ichigo, Chad, Keigo and Mizuiro. It's told from Mizuiro's point-of-view.
** Chapter -17 covers how Renji, Kira, Hinamori and Rukia met as Academy students and how Renji, Hinamori and Kira were put into an advanced class study group while Rukia was left behind in a lower achieving class. It also introduces Hitsugaya as a young child who refuses to consider the validity of training to become a {{shinigami}}.
** Chapter -12.5 covers a past event where Aizen, Hinamori and Rangiku arrange a birthday surprise for Hitsugaya and reveals that Gin gave Rangiku her birth date.
** Chapter "0 Side A" covers the days leading up to Chapter 1, focusing on Ichigo's feelings of powerlessness to help those in trouble, such as the little ghost girl.
** Chapter "0 Side B" covers the days leading up to Chapter 1, focusing on both Rukia receiving her assignment to patrol Karakura Town and Renji receiving his new promotion to Sixth Squad Lieutenant.
** Chapter -16 is Hitsugaya's back story, revealing how he met Rangiku and why he decided to become a {{shinigami}}. It picks up five years after the events in Chapter -17. The chapter was also written to promote the second film which is about Hitsugaya's back story.
** Chapters -108 to -97 cover the Turn Back the Pendulum mini-arc. It covers a nine year period 110-101 years before Chapter 1 and reveals the truth behind Urahara's exile and who the Visoreds really are.
** Imaginary Number 1 is a chapter detailing two Espada having been sent to Hell after their deaths in the {{canon}} as an advertisement for the fourth film, which is set in Hell.
* ''Manga/SchoolRumble'' plot chapters are labeled #1, #2 and so on, but chapters about minor characters are labeled with â™­. There are also a few 'natural' chapters.
* ''Manga/{{Nana}}'' has a book of extra episodes numbered "7.8": this is both a joke on the two protagonists' names (Nana = 7 and Hachi = 8 in Japanese) and a way to say it is meant to be read after volume 7 and before volume 8, it spite of this being published some time after these.
* Invoked in ADV Films' dub of ''Anime/NeonGenesisEvangelion''; the tapes were referred to as "Genesis 0:1", "Genesis 0:2", etc. up to "Genesis 0:13".
* {{Recap episode}}s of ''Anime/CodeGeass'' were numbered (number of the previous episode).5 with the next episode continuing onto the next whole number.
** Which is also the case for some other animes with recap episode (i.e. ''LightNovel/TheLegendOfTheLegendaryHeroes'')
* The ''Manga/{{Saiyuki}}'' main-story series (''Gensomaden'', ''Reload'', and ''Blast'') have normally-numbered chapters organized into numbered "acts"--roughly equivalent to plot arcs. There are fractional numbered acts for omakes, and full-chapter flashbacks are listed as "act.xx".
* In ''Manga/SoulEater'', the three one-shot introductions for each of the three main weapon and meister pairs were, in the collected paperback, retroactively given the chapter numbers .1, .2, and .3.
[[/folder]]

[[folder:Comic Books]]
* The first five issues of ''ComicBook/FunWithMilkAndCheese'' were numbered #1, Other #1, Third #1, Fourth #1, and "First Second Issue."
* ''ComicBook/ZeroHour'' numbered the main storyline backward because it was counting down to... Zero Hour. Various titles in Franchise/TheDCU had tie-in issues numbered #0; most significantly, the issues of ''ComicBook/LegionOfSuperHeroes'' and ''Legionnaires'' that began the Legion's first full-fledged {{reboot}}.
** ''ComicBook/CountdownToFinalCrisis'' did the same thing, counting backwards from ''ComicBook/FiftyTwo''.
** After the ComicBook/{{New 52}} reboot, one special themed month had #0 issues for all DCU titles, telling stories of the characters' origins or early careers.
* This happens occasionally in long running comics that have been restarted various times. Via loopholes in how volumes are decided the editors can shuffle the numbers around to celebrate milestones. For example ''[[ComicBook/SpiderMan The Amazing Spider-Man]]'' (Vol. 2) #59 was renamed {The Amazing Spider-Man} #500 (and the following issues kept the 500+ numbers). Naturally this can be very very confusing, especially when the numbering is reset multiple times in relatively short order.
* ''ComicBook/DCOneMillion'' saw every DCU title jump to #1,000,000 for an issue as the far future DCU interacted with the present day.
* ''ComicBook/GrooTheWanderer'' has had at least three "#1" issues (because it changed publishers, and because "#1" sells better). Original author Sergio Aragonés claimed that ''every'' issue he wrote was #1.
* In a similar manner to DC's original "zero issues", which were {{Flashback}}s to origin stories, Marvel had a FifthWeekEvent of stories set ''before'' the characters' origins ([[ComicBook/SpiderMan Peter Parker]] as a kid; mutants before the founding of the ComicBook/{{X-Men}}, etc), numbered "#-1".
* Long after both events (which it wasn't around for at the time), ''ComicBook/BoosterGold'' had a Zero issue (tying into ''Zero Hour'' ''and'' restating his origin) and a One Million issue (introducing Booster's 1M counterpart, Peter Platinum).
* Given all this, it's almost not unusual that the ''ComicBook/EarthX'' trilogy featured the first issue as "0", the second through thirteenth as "1-12", and the last as "X". (With a number of titled but un-numbered comics in between during the runs of ''Universe'' and ''Paradise X''.
* In 1999, the publisher of ''ComicBook/TwoThousandAD'' decided to stop doing annuals in favour of triple-length [[ChristmasSpecial December issues]], which are cheaper and sell better. Each of these special issues has been given the number of the next year, starting with December 1999's 'prog 2000' and continuing through prog 2001 (December 2000), prog 2002 (December 2001), etc. Naturally, the number of the first issue of January directly follows that of the last issue of November, but the stories in the December issue still fall between them. One wonders what will happen when it actually reaches issue 2000.
* Marvel at one point had "Point One" issues, standalone stories that established the characters' status quo, published as, for example, #37.1 (between #s 37 and 38). Intended as a jumping on point, it might have worked better if any care had been made to ensure that #38 wasn't part four of a six-part story.
* Like Zero Hour above, the miniseries ''Marvel: The Lost Generation'' has the numbering go backwards, matching the time-travelling POV character.
* Back before it ended, the Deadpool Team Up series was numbered backwards, starting at 1000.
* The ''Comicbook/{{Venom}}'' arc "The Circle of Four" got the numbers 13.1 through to 13.5, all during the same month.
* During the late 90s, the ''Comicbook/{{Superman}}'' titles had "triangle numbers", indicating the order they should be read in to follow the ongoing story. When the "Millennium Giants" storyline (which ran from ''Superman: The Man of Steel'' #79, triangle number 15, to ''Superman'' Vol 2 #135, triangle number 20) crossed over into ''ComicBook/{{Aquaman}}'', ''Challengers of the Unknown'', ''Comicbook/TeenTitans'' and ''{{Steel}}'', the crossover issues were given triangles reading 15.1, 15.2, 16.1 and 17.1.
* Marvel's ''ComicBook/OriginalSin'' tie-in minis were named like ''Original Sin X.Y'', where Y is the normal issue number in the mini; nothing to see there, but X was generally ''not'' the issue they came after in the event, but instead the one they came after in the series they tied into. So for example ''Original Sin'' 5.1 didn't come after ''Original Sin'' 5, it came after '''ComicBook/LokiAgentOfAsgard''' 5.
[[/folder]]

[[folder:Fanfic]]
* ''Fanfic/StarkitsProphecy'' is more than a little careless with its chapter numbers. Whether or not numbers are being skipped or duplicated, they are frequently subjected to RougeAnglesOfSatin when spelled out.
* ''[[http://fanfiction.net/s/8745711/1/ Post-SCrash Session 2: The Belorussian Aliens]]'': in chapter 3, a HostileShowTakeover occurs and the fic restarts at chapter 1. However, the next chapter after that one is not 2 but 1,5, as its events precede that of the chapter 2.
[[/folder]]

[[folder:Film]]
* ''Film/TheNakedGun'' series: the second film is numbered 2 1/2 and the third is numbered 33 1/3.
[[/folder]]

[[folder:Literature]]
* In ''Literature/{{Gone}}'', the chapters come with a countdown of days, hours, minutes, and seconds to the climax of the book.
* In ''Literature/LogansRun'', the chapter numbers go down. [[spoiler:Since it ends with a rocket taking off, it's a countdown.]]
* Similarly, the section numbers in ''Literature/EverythingMatters'' count down to the destruction of life on earth. [[spoiler: And when the main character gets the chance to relive part of his life, and the numbers start over.]]
* In Creator/DanAbnett's ''TabletopGame/{{Warhammer 40000}}'' novel ''Literature/{{Titanicus}}'', the chapter numbers are in binary.
* In Margaret Ball's ''Mathemagics'', the chapter numbers are mathematical formulae that can be solved for the actual number. (She lists the solutions in the back.)
* ''Literature/TheCuriousIncidentOfTheDogInTheNightTime'' only has prime-numbered chapters, due to the narrator disliking other numbers.
* ''Storm'' by George R. Stewart is chaptered "The First Day", "The Second Day", "The Third Day" and so on. There are no chapter numbers.
* ''Literature/TheNameOfTheRose'' does the same thing, and subdivides the chapters according to the hours of the monastic day.
* ''Literature/WaysideSchool Is Falling Down'' is stuck on the [[MissingFloor nineteenth story]] for three chapters. The following chapter is headed "20, 21 & 22: Eric, Eric and Eric".
** The previous book, "Sideways Stories from Wayside School," has no Nineteenth chapter at all (since the school isn't supposed to have a nineteenth story, either.) Instead, between chapters 18 and 20 we get a notice saying "there is no nineteenth story. Sorry."
* ''Literature/TheGodsThemselves'' by Creator/IsaacAsimov starts with chapter 6 of its first section, before flashing back to chapters 1-5 (i.e. the story is told out of order but the chapters are numbered in strict chronological order).
** It also breaks all the chapters [[spoiler:(except for the last one)]] in the second section of the book into three parts, numbered 1a, 1b, 1c (all of the action in these chapters are taking place at roughly the same time), 2a, and so on; the letters correspond to three different viewpoint characters.
* The three books in Creator/RobertAntonWilson's ''Schrodinger's Cat Trilogy'' are all Book One, and the parts of each book are all Part One.
* In the ''Literature/AlcatrazSeries'' book four, due to its offbeat style, the book starts on chapter 2, then skips to chapter 6 (mentioning how boring chapters 3-5 were), then from there it proceeds to chapter pi, then 4 1/2, then 42. Eventually you read through Act V, scene III, Chapter No!, Chapter 24601 (a reference to ''Literature/LesMiserables''), Chapter 8675309, Chapter Infinity, and chapter infinity plus one, along with many other crazy chapter titles.
** The titular narrator explains that this is a security precaution against Evil Librarians. Since the Evil Librarians are obsessed with order and putting everything in its place (which is why they're trying to take over the world), their heads will explode if they try to make sense of his numbering scheme.
* ''Literature/TheEyeOfArgon'' includes a Chapter 3 1/2 and a Chapter 7 1/2.
--> '''[[Series/MysteryScienceTheater3000 Mike:]]''' This edition seems to have omitted Chapter Pi.
* ''[[Creator/StephenKing The Running Man]]'' also does a countdown. Appropriate, since the main character has to survive for a specific time to win a prize. [[spoiler:Actually, it's the countdown to his [[FunnyAneurysmMoment suicidal destruction of Games HQ by airplane collision]]]].
* ''Life in the Fat Lane'''s chapters are numbered according to the weight of the protagonist.
* The Ring of Ritornel counts up to chapter 12, then starts counting down again; each chapter in the second half has a title which is a variation on the previous chapter with the same number. The final chapter in numbered x.
* ''How To Eat Fried Worms'' has a chapter-and-a-half, and one chapter literally has only a blob of ink for a chapter name and number. (It's sometimes referred to as "Chapter Splort" in readings.)
* The chapters in ''Franchise/JurassicPark'' are titled "First Iteration", "Second Iteration", etc., in keeping with Ian Malcolm's interest in fractals. Actual fractals (iterations of the Heighway dragon curve) are shown on the chapter pages, but the count is wrong--the "First Iteration" actually has a picture of the third iteration, and so on. (This might be because the first and second iterations don't look very interesting.) In the sequel ''Literature/TheLostWorld1995'', it becomes "First Configuration", "Second Configuration" etc.
* ''Discworld/GoingPostal'', the first non-young-adult Literature/{{Discworld}} novel since ''The Colour of Magic'' to feature chapters, has a chapter 7A instead of a chapter 8 (because the number 8 is considered unlucky on the Discworld).
** And while ''Discworld/ThiefOfTime'' (as stated above) does not have chapters or chapter numbers, it does have a ''"tick"'' in the middle of each break in the text... at least until [[TimeCrash it doesn't]]
* The chapters of ''Literature/IAmTheMessenger'' are all playing cards, as each of its four acts begin with the main character receiving an Ace of each of the suits. [[spoiler: And then it all goes out the window once he receives the Joker.]]
* ''The Man Who Loved Only Numbers'', a biography of Paul Erdos, starts with chapter 0, then goes up through one, two, e, three, pi and so on, before ending with an epilogue: Chapter Infinity.
* Aside from the prologue, each chapter of ''Literature/ANightInTheLonesomeOctober'' by Roger Zelazny is titled October 1, October 2, etc., all the way to October 31, as each chronicles the events of that day.
* All the chapters in Zelazny's ''Roadmarks'' are numbered either "One" or "Two," indicating separate plot threads.
* In Roddy Doyle's book, The Giggler Treatment, there were a few flashback chapters. The narrator apparently lost track of what chapter he was on after those and began naming chapters things like, "The Chapter After That Last One", "Chapter Mammy Doyle" and "This Chapter Is Named After Elvis Presley Because He Lives Under The Shed In Our Back Garden."
** Not forgetting "Chapter Something"!
** One of the few chapters that doesn't follow this format, the sixteenth chapter, is actually ''called'' "Chapter Sixteen", possibly as a gag.
* ''The Captive'' by Scott O'Dell uses Mayan numerals for chapter numbers.
* In ''Survivor'' by Creator/ChuckPalahniuk, the chapter numbers count down, as do the page numbers.
* The ''Franchise/DoctorWhoExpandedUniverse'' novels are full of this. There has been at least one instance of numbers counting down. It almost always has something to do with TimeTravel.
** The ''Series/{{Torchwood}}'' novel ''The Men Who Sold The World'' has six Chapter Nineteens, each (except the last one) ending with [[spoiler: Mr Wynter activating the time-gun and travelling back to the start of Chapter Nineteen]]. It also has flashback chapters headed "X Years/Months/Weeks Earlier..." and a prologue and epilogue headed "100,000 BC"
* In Creator/JohnVarley's time travel novel ''Mammoth,'' the chapters are numbered in ''absolute'' chronological order, which is ''not'' the order the story is told in.
* [[Creator/IainBanks Iain M. Banks]]'s ''Literature/UseOfWeapons'' has two interleaved streams of chapters, one conventionally numbered in sequential Arabic figures for the main story set in the Present, and one counting backwards in Roman numerals working through the protagonist's backstory.
* ''Tik Tok'' has twenty-six chapters, which don't have numbers, but each one begins with the appropriate letter of the alphabet in a very large [[UsefulNotes/{{Fonts}} font]]. (So chapter one begins "As I look..", chapter two begins "Broaching the second chapter..." and so on. The writer has to cheat a little: for example, chapter four has "Hey Dummy!" and chapter seventeen has "Q. Cue the bloody rainbow...")
** ''Literature/TheNeverendingStory'' does the same thing.
* ''Literature/FamilyBites'' by Lisa Williams has "Chapter Twenty-Four - Part One" and "Chapter Twenty-Four - Part Two".
* ''Imzadi'', a Series/StarTrekTheNextGeneration novel by Peter David, doesn't have chapter numbers, but it has section titles such as "The End", "The Beginning of the End", "Interlude", and "The End of the Beginning". Though thematically appropriate for the sections, and entirely understandable for a time travel novel, they have nothing to do with their locations in the book.
* In the Greek version of Literature/TheBible, the Septuagint, the Book of Esther has additions not found in the Hebrew versions. They were numbered to come after the rest of the book, but later re-inserted into more appropriate places. Consequently, the chapter numbers are out of order, and the book actually begins with Chapter 11.
* Alain Damasio's ''La Horde du contre-vent'' has reverse numbered ''pages''. It can be startling if you only notice it halfway through the book.
* Georges Perec's ''La disparition'' (translated into English as ''A Void'') is a lipogram - the letter E never appears in the text. It's 26 chapters long, but chapter 5 is missing.
* Literature/AtlantaNights has two chapters called Chapter 12 and no chapter 21. There's no real reason behind it, other than adding to the overall lack of professionalism in the book.
* The ''Literature/ThursdayNext'' books begin every chapter on a right-hand page. If the previous chapter ends on a right-hand page, the intervening left-hand page is blank. [[ThirteenIsUnlucky There is no Chapter 13]], although one is listed in the contents -- with the page number of the blank page before Chapter 14.
* The book ''The Dancing Wu Li Masters'' (Think ''Literature/ZenAndTheArtOfMotorcycleMaintenance'') numbered each chapter "Chapter One," with a different title under each one. The philosophy behind this is eventually explained in the book.
* ''Literature/LookingForAlaska'' is separated into two sections, Before and After. Each section is divided into days (like ''10 days before'' or ''75 days after''), with Before counting up to [[spoiler: Alaska's death]] and After wrapping everything up.
* A few ''Literature/CaptainUnderpants'' books have chapters numbered X 1/2, and one even has one with a 3/4.
* The ''OttoUndercover'' series by RheaPerlman does this a lot. For example, in the first book, the table of contents lists "Chapter Minus 1", "Chapter 0", "Chapter Regular 1", "Too Many Chapters", and "The End". The actual names of the chapters in the book are "Chapter Minus 1", "Chapter 0", "Chapter Regular 1", "Chapter 2", "Chapter 2½", "Chapter 3", "Chapter 4", "Rude Interruption of the Story, Number One", "Chapter 4 Again", "Rude Interruption of the Story, Number Two", and so on...
* The Spanish novel ''La tournée de Dios'', much like the example of The Gods Themselves, has the story told out of order but the chapters numbered in strict chronological order. The author lampshades this in the prologue proposing options to the reader including cutting all pages then putting them in order or directly throwing the book out of the window without reading it (although he doesn't believe the last option to be the best)
* Brazilian novel ''A Lua Vem da Ásia'' has: "Chapter First" - "Chapter 18th" - "Chapter Twelve" - "(No chapter)" - "Chapter without Sex" - "Chapter 99" - "Chapter Twenty" - "Chapter I (again)" - "[[NoTitle Chapter ]]" - "Chapter CLXXXIV".
* In Creator/WilliamAlexander's ''Literature/GoblinSecrets'', the chapters are listed as Act and Scene numbers, like a play's.
* In Creator/RJAnderson's ''Literature/{{Ultraviolet}}'', it starts with zero, and ends with infinity, and includes not only the number but a parenthetical comment about how the number appears to the synesthete heroine.
* ''If You're Reading This, it's Too Late'' from the ''Literature/SecretSeries'' has the chapters in reverse order (starting with Chapter 34 and ending with Chapter 1) because the author hopes the book (and the secrets contained within) will explode like the countdown timer on a bomb. In ''This Isn't What It Looks Like'' there are normal chapters, but also negative chapters for the main protagonist, Cass, and what she's doing in the past.
[[/folder]]

[[folder:Live Action TV]]
* ''Series/MysteryScienceTheater3000'' began as a local TV show (on Minneapolis station KTMA), then became a 10-year national series on The Comedy Channel (later Comedy Central) and then the Sci-Fi Channel. Since all of its cable-era marketing treated the first national season as Season 1, fans and show archivists retroactively "numbered" the KTMA episodes "K01" through "K21", with an unaired pilot-show fragment numbered "K00". Confusingly, Website/IMDb originally called the KTMA shows "Season 0", but has now renumbered them all to Seasons 1-11, breaking with all other information sources (but oddly keeping the "0" number for the "pilot").
* ''Series/{{QI}}'' labels its seasons not with numbers but with letters, with series 1 being called "Series A", series 2 being "Series B" and so on.
[[/folder]]

[[folder:Music]]
* Professor Peter Schickele (University of Southern North Dakota at Hoople) is the world expert on the music of Music/PDQBach - the last and certainly least of Johann Sebastian Bach's sons. He has assigned Schickele numbers (S) to PDQ Bach's works.
** The ''1712 Overture'' is S. 1712.
** ''The Classical Rap'' is S. 1-2-3
** ''Einstein on the Fritz'' is S. e=mc2
** ''The Erotica Variations'' is S. 36EEE
** ''Hansel and Gretel and Ted and Alice'' (an opera in one un-natural act) is S.2n-1 (odd!)
** ''The 'Howdy' Symphony'' is S. 6 7/8
* Creator/StanFreberg's "Wun'erful, Wun'erful!" originally spanned two sides of a 45 RPM record, labeled "Side Uh-One" and "Side Uh-Two."
* The ''[[Music/EmersonLakeAndPalmer Karn Evil 9 Suite]]'' was originally four tracks -- called ''First Impression (Part One)'' (which ended Side 1 of the album), ''First Impression (Part Two)'', ''Second Impression'', and ''Third Impression''. At least one compilation album has featured a track which was supposed to be ''Second Impression'' but was actually ''First Impression (Part Two)''.
[[/folder]]

[[folder:Tabletop Games]]
* The original Malkavian clanbook in ''TabletopGame/VampireTheMasquerade''. So much so it calls the Appendixes "Liver One" and "Kidney Two".
* The TabletopGame/{{Normality}} game master's guide, which only manages to be ''a little'' less weird and disturbing than the other book. And that's very, very weird and disturbing. [[spoiler: Part Juan, Past Dues, Parrot Tree, Parched Fief, Park Sex.]]
[[/folder]]

[[folder:Video Games]]
* ''VideoGame/{{Braid}}'' began with World 2 and works it way to World 6, with World 1 being the last world you visit. It could be symbolic of the fact that [[spoiler: in the final level, time flows backwards.]]
** Similarly, the stages in World 1 count down from 4 to 1, probably for the same reason.
* The stages in ''VideoGame/RadiantSilvergun'' are numbered not by the order the player goes through them, but by the time period they take place. Because of this, the final stage, which is set millions of years in the past, is Stage 1.
* The story of VideoGame/TheWorldEndsWithYou is played by week. During the first week, each day starts with a "THE XTH DAY" screen and ends with a "CHAPTER TITLE" screen. The second week starts over, so your eighth day is again "THE 1ST DAY", ninth is "THE 2ND DAY" and so on. The first day of the ''third'' week, however, is [[spoiler:"7 DAYS LEFT", Week 3 Day 2 is "6 DAYS LEFT", and Day 7 is "THE LAST DAY".]] The unlockable bonus chapter is "ANOTHER DAY".
* The version of TabletopGame/FreeCell that comes with Windows has either 32,000 (pre-XP) or one million games, which are given positive numbers starting from 1. However, there are also [[EasterEgg secret deals]] -1 and -2, which are [[UnwinnableByDesign impossible]]. Vista added deals -3 and -4, which are [[ItsEasySoItSucks quite the opposite]].
* ''VideoGame/{{Minecraft}}'' Alpha and Beta releases had version numbers in the format of 1._____, eventually culminating in 1.9 prerelease 5. The "final" version of ''Minecraft'' is simply numbered version 1.0.0.
* The arcade game ''VideoGame/KamenRiderBattleGanbaride'' used straight numbers for its first several sets. When ''Series/KamenRiderOOO'' premiered, the sets were relaunched with set 001, when ''Series/KamenRiderFourze'' premiered it was relaunched again with set 01, and ''Series/KamenRiderWizard'' led to sets starting with "Shabadoobie". The same thing happens with ''VideoGame/SuperSentaiBattleDiceO'', where the early sets just had numbers, the ''Series/KaizokuSentaiGokaiger'' sets used "DX-{number)", the ''Series/TokumeiSentaiGobusters'' sets used "Tokumei-(number)", and the ''Series/ZyudenSentaiKyoryuger'' sets use "Gaburincho-(number)" (or "GB-(number)" for short).
* ''VideoGame/{{Touhou}}'' uses decimals for in-between installments. 7.5, 10.5, 12.3, 13.5, and 14.5 were fighting games, 9.5 and 12.5 were unique photographing games, 12.8 was a LowerDeckEpisode with Cirno as the main character, and 14.3 was a sequel to 14 with Seija Kijin as the main character. (Yes, there were 3 games between 12 and 13. No, they aren't examples of CapcomSequelStagnation.)
* ''{{VideoGame/Marathon}}'' has ''Marathon'', ''Marathon 2: Durandal'', and ''Marathon Infinity'' [[note]](more of a riff on the level editor being an important part in the package as well as an AlternateUniverse -oriented plot than a numbering joke, though)[[/note]]. As a continuation of this, the updated fan-supported source port version is called "Aleph One" - infinity plus one.
[[/folder]]

[[folder:Webcomics]]
* ''Webcomic/{{Adventurers}}'' had hundreds of strips numbered 999 during the final boss battle arc, as a joke on {{Cap}}s in [=RPGs=].
* The two prequel books for ''Webcomic/TheOrderOfTheStick'' are numbered volume 0 and volume -1.
* ''Webcomic/{{Homestuck}}''
** It was originally intended to have 7 acts. As time went on, however, more plot threads and characters were introduced, requiring more acts. Hence, we have, in order, Act 1, Act 2, Act 3, Intermission, Act 4, Act 5 Act 1, Act 5 Act 2, Intermission 2, Act 6 Act 1, Act 6 Intermission 1, Act 6 Act 2, Act 6 Intermission 2, Act 6 Act 3, Act 6 Intermission 3, Act 6 Act 4, Act 6 Intermission 4, Act 6 Act 5 Act 1, Act 6 Act 5 Act 2, Act 6 Intermission 5 (including Intermissions 1 to 6 and an "Interfishin"), Act 6 Act 6 Act 1 and a currently ongoing Act 6 Act 6 Intermission 1.
** It went BACKWARDS from Act 6 Act 5 Act 2 to Act 6 Act 5 Act 1.
--->'''Caliborn:''' GO BACK.
--->'''Hussie:''' No.
--->'''Caliborn:''' I MEAN BACKFORWARD.
--->'''Hussie:''' No.
--->'''Caliborn:''' GO BACKFORWARD TO ACT ACT ACT WHATEVER.
--->'''Hussie:''' No.
** It is lampshaded by Caliborn once more:
--->THERE ARE A LOT OF THESE [ACTS]. AND THEY ONLY GET LONGER. AND THEN BEGIN TO SPLIT? INTO ACT ACTS. AND ACT ACT ACTS. TRUST ME. THE STRUCTURE RAPIDLY DETERIORATES INTO UTTER NONSENSE. OR AT LEAST IT WOULD. IF IT HAD NOT ALREADY BEGUN. AS SUCH A REEKING PILE OF SHIT OUT OF THE BOX.
** As well as that, the acts are badly proportioned, as can be seen on [[http://readmspa.org/stats/ this site]].

[[/folder]]

[[folder:Web Original]]
* "A Beginner's Guide To The British" has Part One, Part Two, Part [[strike:Four]] three (oops), Part Four, and Part [[strike:Four]] five.
* WebVideo/TheNostalgiaCritic, in his Top 11 Mind**** Countdown, used entries such as "Number Guttenburg" "Number Lamp" and "Number Number" (depicted by a # sign).
* [[http://bookofsand.net/hypertext/ The Book of Sand]] puzzle does this with PAGE numbers. The page numbers are 999, 1001, 40514, 82499, 71077345, [[MouthfulOfPi 3141592654]], 11111000101, and 23^9. Worse yet, [[OutOfOrder they don't take place in order]]. Rather, the reader has to put them in order based on context of the story.
[[/folder]]

[[folder:WesternAnimation]]
* From the third season of ''WesternAnimation/{{ReBoot}}'' on, where the show kicked off a full MythArc, episodes were numbered like versions of software in the formula [=vX.Y.Z=] where X is the season, Y is which StoryArc of the season, and Z is which episode of the StoryArc.
[[/folder]]

[[folder: Non Fiction ]]
* One should not be surprised to open up a programming language reference book and see that the chapter numbers start at zero. If the author of the book has done this, the language will almost certainly use zero as the index of the first item in an array. Probably the languages to get this treatment the most are C and C++.
** Some math books also do this.
** John Conway's ''On Numbers and Games'' not only starts at chapter zero, it's also divided into a "zeroth part" and a "first part."
* The INTERCAL [[http://www.catb.org/~esr/intercal/intercal.txt.gz reference manual]] has a tonsil instead of an appendix.
-->"Since all other reference manuals have Appendices, it was decided that the INTERCAL manual should contain some other type of removable organ."
* Similarly, one strategy guide for the computer game ''Creator/MontyPython's Complete Waste of Time'' includes spleens instead of appendices, and they're scattered throughout the book rather than all placed at the end. Most of these are just quotes from various ''Creator/MontyPython'' sketches that are vaguely relevant to that part of the game.
* Donald Knuth has a tendency to give his software idiosyncratic ''version numbers''. The release versions of his font-design program METAFONT are 2, 2.7, 2.71, 2.718, etc, asymptotically leading to the constant "e"; similarly, the release versions of his typesetting program [=TeX=] are 3, 3.1, 3.14, and so on, converging to "pi".
** It's been claimed (possibly by Knuth himself) that when he dies the version numbers will be changed to e and pi respectively, and any further bugs will thereby be considered features.
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