A spoiler is a piece of information that, when released too early, might spoil someone's enjoyment of a book, movie, story, etc. For example, information about who-done-it spoils a mystery; information about who-ends-up-with-whom could spoil a romantic story; or who wins the battle and who dies could spoil an epic about a war between good and evil. Anything about plot twists or surprises could be a spoiler.
Spoiler notices or alerts are sometimes included in article before the potentially spoiling content in order to warn readers.
On the Inheritance Cycle Wiki, spoiler alerts are posted at the top of pages. They look like this:
but will appear in the upper right corner of the page.
- Wikipedia article on Spoilers