This is when an author writes in an atypical pattern. The reasons for this can vary, from LeaningOnTheFourthWall (if it's related to the story in some way), to keeping certain plot points and twists hidden to the very end (e.g. avoiding gender pronouns for a SamusIsAGirl twist) to simply being a stylistic choice. Some types of self-imposed challenges include writing in a particular metre, or making each line a letter longer than the one that preceded it; writing in code (e.g. replacing words with ones that appear a few places afterwards in the dictionary); avoiding certain common letters (the correct term for this is a lipogram, by the way); using words that display some sort of complex pattern (e.g. making large chunks of the story alliterative or in [[FunWithPalindromes palindromes]]); drabbles (stories of precisely 100 words) and many more.

Remember this applies to any challenge imposed on the author by themselves, so normal deadlines and schedules don't count, though improvising with limited resources or using a particularly strict time limit does.

The alternative name "{{Oulipo}}" is from a group of [[http://en.wikipedia.org/wiki/Oulipo French writers]] who were dedicated to this style of writing. TheOtherWiki also [[http://en.wikipedia.org/wiki/Constrained_writing has an article on the concept]].

Some authors might adopt this as a SignatureStyle. UnconventionalFormatting can be related. When this is used within an otherwise normal piece of writing to show something specific then it is PaintingTheMedium.

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!!Examples:

[[foldercontrol]]

[[folder:Literature]]
* ''Literature/AVoid'' (and ''La Disparition'', its Gallic original) shows a lack of fifth glyphs.
* ''Literature/{{Gadsby}}: A Story of Over 50000 Words Without Using the Letter "E"'' by Ernest Vincent Wright.
* Mike Keith has rewritten Creator/EdgarAllanPoe's ''The Raven'' with the limitation that [[spoiler: words must have the same number of letters as the corresponding digit of pi]]. Read it full here: http://www.cadaeic.net/naraven.htm
* ''Literature/LeTrainDeNullePart'' is a French novel with no verbs.
* In her first ''Literature/ThievesWorld'' short story, "The Secret of the Blue Star", Creator/MarionZimmerBradley carefully tried to [[spoiler: avoid referring to the gender of the magician Lythande to conceal the TwistEnding that [[SamusIsAGirl Lythande is a woman]].]] She did slip up at one point, however.
-->Lythande drew from the folds of his robe a small pouch containing a quantity of sweet-smelling herbs, rolled them into a blue-grey leaf, and touched his ring to spark the roll alight. He drew on the smoke, which drifted up sweet and greyish.
* Creator/DavidLangford's "[[http://www.ansible.co.uk/writing/drabbles.html A Surprisingly Common Omission]]" is a drabble written without using the letter E.
* Creator/HarlanEllison once sat in a department store window for five hours, with the challenge being that he write a 500+ page novel in that time-frame. And pulled it off. In addition, he's written several short stories in this manner, with other people providing written prompts just before he starts. One of his better-known storefront stories, "From A to Z in the Chocolate Alphabet", is a series of 26 short, disturbing proto-{{Creepypasta}} vignettes (one for every letter of the alphabet) written over the course of eight hours in the front window of a science fiction bookstore.
* UsefulNotes/NaNoWriMo's idea is to write a novel with at least X words in a month. The default value of X is 50,000, but some people go for up to million words.
** Similarly, ScriptFrenzy is a challenge to write 100 pages of script.
** On the other end of the spectrum, there's flash fiction, short stories under a certain length, and "drabbles", stories exactly 100 words long.
* Creator/DrSeuss:
** He wrote ''Literature/TheCatInTheHat'' as a challenge to write an interesting story using a very small vocabulary of words which a 6 year-old should know.
** Reportedly ''Literature/GreenEggsAndHam'' was a challenge to create an interesting children's story using no more than 50 different words.
* ''Eunoia'', by Christian Bok, is a collection of poetic prose. Each entry only uses words that use a single vowel. (The word "eunoia" itself is the shortest word in English that uses all five vowels). http://en.wikipedia.org/wiki/Eunoia_(book)
* Creator/IsaacAsimov wrote [[http://en.wikipedia.org/wiki/Insert_Knob_A_In_Hole_B Insert Knob A In Hole B]] live on television (although he admitted he saw the challenge coming and prepared for it). The preparation time was a few minutes before the show started.
* JimButcher wrote ''Literature/CodexAlera'' on a bet that he could write a story using what he thought were two terrible ideas: The LostRomanLegion and ''Franchise/{{Pokemon}}''.
* Creator/PoulAnderson wrote the essay "Uncleftish Beholding" in which he described basic atomic theory and the periodic table in a manner as if English had never adopted any French, Latin, or Greek vocabulary but instead only used its Germanic roots:
-->Some of the higher samesteads are splitly. That is, when a neitherbit strikes the kernel of one—as, for a showdeal, ymirstuff-235—it bursts it into lesser kernels and free neitherbits; the latter can then split more ymirstuff-235. When this happens, weight shifts into work. It is not much of the whole, but nevertheless it is awesome.
* ''[[http://en.wikipedia.org/wiki/Alphabetical_Africa Alphabetical Africa]]'' is a novel in 52 chapters, beginning with only words that start with 'a', and then 'a' and 'b', up to chapter 26, where all the alphabet can be used. From chapter 27 to 52, the letters words can start with recede back to 'a'.
* ''[[http://spinelessbooks.com/2002/book/index.html 2002: A Palindrome Story]]'' is a story written with exactly 2002 [[FunWithPalindromes palindromic]] words.
* In ''Literature/TheThreeMusketeers'', [[TheSmartGuy Aramis]] mentions that he has written a poem with each line consisting of only one syllable.
* In the Creator/GeneWolfe short story ''My Book'', the narrator is writing a book starting with the ''last'' word and working ''backwards''.
[[/folder]]

[[folder:Webcomics]]
* ''Webcomic/{{xkcd}}'' has [[http://xkcd.com/1045/ a comic]] about this.
[[/folder]]

[[folder:Web Original]]
* ''Blog/WhatIf'': After [[http://what-if.xkcd.com/75/ being asked what the most inconvenient word to type on an old cellphone would be]] (it's "nonmonogamous", which makes you hit the 6 key 16 times in a row), Randall has some fun with sentences that can only be typed with the left or the right hand (on a standard QWERTY keyboard). He also puts together some sentences that can only be typed using the home row or the top row. He comes up with some ''very'' [[ARareSentence rare sentences]] (which are also hilarious.)
--> ''(left hand)'' Ferret sex at great rates [[labelnote:''Alt Text'']]MEET SINGLE FERRETS IN YOUR AREA TONIGHT[[/labelnote]]\\
''(right hand)'' Buy my puppy milk, LOL\\
''(home row)'' [[KingArthur Galahad]] has a Flash SSD\\
''(top row)'' We owe it to you to pepper your puppy
[[/folder]]

[[folder:Western Animation]]
* ''WesternAnimation/TheSimpsons'': Multiple InUniverse examples.
** When Homer [[Recap/TheSimpsonsS11E3GuessWhosComingToCriticizeDinner becomes a food critic]], he writes a review without using the letter E. That's because the E key on his typewriter is broken.
** [[Recap/TheSimpsonsS5E18BurnsHeir Mr Burns tells Lenny that he will be fired unless he is able to explain why he shouldn't be without using the letter E]].
-->'''Lenny''': Uh, I'm a... good... work... guy... \\
'''Burns''': You're fired. \\
'''Lenny''': But I didn't say... \\
'''Burns''': [[YourBlankIsBroken You will.]] ''[pushes trapdoor button]'' \\
'''Lenny''' ''[falling]'': '''[=EEEEEEEEEeeeeeeeeeeeee!=]'''
[[/folder]]
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