Canon (fiction)

In fiction, canon is the material accepted as "official" in a fictional universe. It is often contrasted with, or used as the basis for, works of fan fiction. The term "canon" can be used either as a noun, referring to "the original work from which the fan fiction author borrows," or as an adjective to describe whether or not certain elements are accepted as authoritative parts of the fictional universe. Fan-fiction would be described as "non-canon," while an event from the official source material would be "canon." The alternative term mythology is often used, especially to refer to a richly detailed fictional canon requiring a large degree of suspension of disbelief (e.g. an entire imaginary world and history).

Origin
The use of the word "canon" in reference to a set of texts derives from Biblical canon, the set of books regarded as scripture, as contrasted with non-canonical Apocrypha. The term was first used by analogy in the context of fiction to refer to the Sherlock Holmes stories and novels, written by Sir Arthur Conan Doyle. Ronald Knox used the term in a 1911 essay "Studies in the Literature of Sherlock Holmes" to distinguish Doyle's works from subsequent pastiches by other authors. It has subsequently been applied to many media franchises. Among these are science fiction franchises such as Star Trek, Star Wars, Halo, Fallout, Mass Effect and Doctor Who, in which many stories have been told in different media, some of which contradict or appear to contradict each other.

Canonicity
When there are multiple "official" works or original media, the question of what is and what is not canonical can be unclear. This is resolved either by explicitly excluding certain media from the status of canon (as in the case of Star Trek), by assigning different levels of canonicity to different media (as in the case of Star Wars), by considering different but licensed media treatments official within their own continuities but not across them (as with Battlestar Galactica), or not resolved at all. The use of canon is of particular importance with regard to reboots or re-imaginings of established franchises, such as the 2009 Star Trek film, because of the ways in which it influences the viewer experience.

The official Star Trek website describes Star Trek canon as "the events that take place within the live-action episodes and movies" (that is, the television series Star Trek, Star Trek: The Next Generation, Star Trek: Deep Space Nine, Star Trek: Voyager, Star Trek: Enterprise, and the Star Trek motion pictures). Events, characters and story lines from tie-in novels, comic books, video games and Star Trek: The Animated Series are explicitly excluded from the Star Trek canon, but the site notes that elements from these sources have been subsequently introduced into the television series, and says that "canon is not something set in stone." One example of a non-canonical element that later became canonical in the Star Trek universe was the name "Tiberius" becoming the official middle name of Enterprise captain James T. Kirk. The name was introduced in the Star Trek animated series, and was later added into the official biography of the character by its mention in the live-action film Star Trek VI: The Undiscovered Country.

The Star Wars canon exists on several levels. The highest level is the six Star Wars films, and statements by George Lucas; tie-in fiction from the Expanded Universe has a different level of canonicity. The complex system is maintained by Leland Chee, a Lucasfilm employee. The makers of Doctor Who have generally avoided making pronouncements about canonicity, with Russell T Davies explaining that he does not think about the concept for the Doctor Who TV series or its spin-offs.

Fanon
Fan fiction is almost never regarded as canonical. However, certain ideas may become influential or widely accepted within fan communities, who refer to such ideas as "fanon", a portmanteau of fan and canon.

Fanon is a common feature in large franchises and fictional universes where there are many canon and non-canon works, as in the Star Trek universe.