Constrained writing is a literary technique in which the writer is bound by some condition that forbids certain things or imposes a pattern.
Constraints are very common in poetry, which often requires the writer to use a particular verse form.
Description
Constraints on writing are common and can serve a variety of purposes. For example, a text may place restrictions on its vocabulary, e.g. Basic English, copula-free text, defining vocabulary for dictionaries, and other limited vocabularies for teaching English as a second language or to children.
In poetry, formal constraints abound in both mainstream and experimental work. Familiar elements of poetry like rhyme and meter are often applied as constraints. Well-established verse forms like the sonnet, sestina, villanelle, limerick, and haiku are variously constrained by meter, rhyme, repetition, length, and other characteristics.
Outside of established traditions, particularly in the avant-garde, writers have produced a variety of work under more severe constraints; this is often what the term "constrained writing" is specifically applied to. For example:
Reverse-lipograms: each word must contain a particular letter. Univocalic poetry, using only one vowel. Mandated vocabulary, where the writer must include specific words (for example, Quadrivial Quandary solicits individual sentences containing all four words in a daily selection). Bilingual homophonous poetry, where the poem makes sense in two different languages at the same time, constituting two simultaneous homophonous poems. Alliteratives or tautograms, in which every word must start with the same letter (or subset of letters; see Alphabetical Africa). Lipogram: a letter (commonly e or o) is outlawed. Acrostics: first letter of each word/sentence/paragraph forms a word or sentence. Abecedarius: first letter of each word/verse/section goes through the alphabet. Palindromes, such as the word "radar", read the same forwards and backwards. Anglish, favouring Anglo-Saxon words over Greek and Roman/Latin words. Pilish, where the lengths of consecutive words match the digits of the number π. Anagrams, words or sentences formed by rearranging the letters of another. Limitations in punctuation, such as Peter Carey's book True History of the Kelly Gang, which features no commas. One syllable article, a form unique to Chinese literature, using many characters all of which are homophones; the result looks sensible as writing but is very confusing when read aloud. Chaterism, where the length of words in a phrase or sentence increases or decreases in a uniform, mathematical way. Aleatory, where the reader supplies a random input. Erasure, which involves erasing words from an existing text and framing the result on the page as a poem.
The Oulipo group is a gathering of writers who use such techniques. The Outrapo group uses theatrical constraints.
There are a number of constrained writing forms that are restricted by length, including: Six-Word Memoirs: 6 words Haiku: ~ 3 lines (5–7–5 syllables or 2–3–2 beats recommended.) Minisaga: 50 words, +15 for title Drabble: 100 words Twiction: espoused as a specifically constrained form of microfiction where a story or poem is exactly 140 characters long. Sijo: three lines average 14–16 syllables, for a total of 44–46: theme (3, 4,4,4); elaboration (3,4,4,4); counter-theme (3,5) and completion (4,3).