For software, see Wikipedia:Software (WP:SOFT); for Spoken Wikipedia, see Wikipedia:WikiProject Spoken Wikipedia (WP:WSW). For Wikipedia guidelines regarding non-spoiler warnings, see Wikipedia:No disclaimer templates (WP:NDT).

A spoiler is a piece of information in an article about a narrative work (such as a book, feature film, television show or video game) that reveals plot events or twists. If someone hasn't read, watched or played the material to which the warning refers, they might wish to avoid reading the spoiler before fully experiencing the work. Because some people prefer to avoid spoilers, however, it became common on the Internet to put before such descriptions a spoiler warning. In scholarly reference works, however, this is rare, and thus spoiler warnings are generally avoided on Wikipedia.

Concern about spoilers should never be a reason for any decisions about the structure, content, or formatting of an article. If a piece of information that could be considered a spoiler is one of the most essential aspects of a topic (remembering that fictional topics should be considered from the perspective of the real world, not fictional worlds) it should be present in the article lead. To do otherwise is, at its best, bad encyclopedia writing, and at its worse, a violation of Wikipedia:Neutral point of view.

Note that in cases where plot details genuinely are not widely known (such as when writing about an unreleased work) care must be taken not to violate Wikipedia's policies on original research.

The term "spoiler," when used in this sense, is a neologism that is inappropriate for Wikipedia. (See Wikipedia: Manual of Style (neologisms) Furthermore, as Wikipedia is an encyclopedia, it is assumed that it will contain information - in fact, it is stated explicitly in the general content disclaimer that "WIKIPEDIA CONTAINS SPOILERS AND CONTENT YOU MAY FIND OBJECTIONABLE". To warn about such content is redundant, and, as we don't warn about other objectionable content, including, in cases such as Jyllands-Posten Muhammad cartoons controversy, content that people have been killed over, silly.

• Spoiler tags are redundant when used in ==Plot== or other sections that are clearly going to discuss the plot.

• Spoiler warnings may be used where the editors proposing them can provide a compelling and justifiable reason to insert one. Such reasons should show that knowledge of the spoiler would likely substantially diminish the readers enjoyment of the work. Restrict such warnings to areas where a reader wouldn't reasonably expect to read a spoiler.

• A spoiler warning is a courtesy note to readers, such as those who find articles from search engine results. As such it's more of a reminder note and not a label to be used for every spoiler. Such tags should only be used once in an article. Such a note is never guaranteed.

• Use only {{Spoiler}} to mark spoilers.

• Spoiler warnings must not interfere with NPOV, completeness, encyclopedic tone, or other elements of article quality.

• Spoiler warnings must not be used on ancient texts, literary classics, classic films, or works whose plot is 'common knowledge'. There is some support for use in more recent works. While this is often obvious, grey-area situations should avoid the use of spoiler templates or discuss the matter on the individual article's talk page.

• Spoiler warnings must never be used for non-fictional subjects. For non-fictional subjects that still rely on an element of surprise, such as magic tricks or puzzles, use section heads that give a clear sense of where tricks and secrets might be revealed.

In mid to late 2006, a spoiler template before the fact that Snape Kills Dumbledore in Harry Potter and the Half-Blood Prince would be warranted. Due to the wide dissemination of this information, however, a spoiler tag would not currently be appropriate. The same reasoning can be used for major spoilers in Ender's Game, The Usual Suspects, and The Sixth Sense.

The following methods should never be used to obscure spoilers:

• Making "spoiler free" parallel versions (content forks) of an article. (Since Wikipedia content is available under the text of the GNU Free Documentation License, creating parallel versions outside of Wikipedia is generally acceptable.)

• Deleting relevant, neutral and verifiable information about a narrative work from Wikipedia "because it's a spoiler".

• Structuring an article around spoilers, confining them to a particular area of the article (e.g. under ==Plot==), when unnecessary or in a way that decreases article quality.

• In various Internet discussion forums, a widespread convention is the insertion of blank (or virtually blank) lines before a spoiler (which removes the offending text from the reader's view, until he/she scrolls to the next page). Obviously, this is unacceptable in a general-purpose encyclopedia.

• On the Usenet computer network, a popular method of concealing spoilers (and sometimes, offensive material) is ROT13 encryption. Again, this is unacceptable in a general-purpose encyclopedia.

• Another common method of hiding spoilers from readers is to change the color of the text to match that of the page background, thus rendering the text unreadable until highlighted by the reader in a selection. Hiding text in this manner is unacceptable here because it requires explanation to readers unfamiliar with the practice, and because it may be incompatible with computer accessibility devices such as screen readers. Also, some web browsers highlight text by inverting the colors of the text and background. In these browsers, for white text on a white background, highlighting produces black text on a black background. Also, it is possible for a user to set their browser to refuse to change text color (just as they can refuse to display images); text-only browsers (such as Lynx) may likewise disregard requests to change text color. In addition, it renders the text unprintable.