There is no consensus regarding who has the authority to decide what is or isn't canonical, with copyright holders usually declaring themselves the authorities when they want to erase or
retcon materials that were approved by the setting's original creator (with
Star Wars being an example). The definition of canon is of particular importance with regard to
reboots or re-imaginings of established franchises, such as
the Star Trek 2009 remake, because of the ways in which it influences the viewer experience.
Examples The official
Star Trek website describes the
Star Trek canon as "the events that take place within the episodes and movies", referring to the live-action television series and
films, with
Star Trek: The Animated Series having long existed in a
nebulous gray area of canonicity. Events, characters, and storylines from tie-in novels, comic books, and video games 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". After
Disney's acquisition of the franchise, Lucasfilm designated all Expanded Universe material published before 25 April 2014 (other than the first six theatrical films and the 2008
The Clone Wars film and TV series) as the non-canonical "Legends" continuity. Material released since this announcement is a separate canonical timeline from the original George Lucas Canon, with all narrative development overseen by the Lucasfilm Story Group. 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 television series or its
spin-offs. The television series
The Simpsons has an example of non-canonical material, being the
Treehouse of Horror episodes, a series of Halloween-themed specials with several stories that take place outside the show's normal continuity.
Productions under
Walt Disney Animation Studios are considered by
The Walt Disney Company as the canonical stories under the company's "Disney" brand. Therefore, sequels, prequels, television series, or other related media produced by other studios of the company (as is the case of
Disneytoon Studios and
Disney Television Animation productions that serve as a continuity of the films), and events in other media like books or video games, are ignored within the main Disney brand, focused on productions under Walt Disney Animation Studios, thus other productions and media being considered non-canonical events. Several
anime television series adapted from
manga stories count with some extra episodes with original stories that are not part of the original manga, often being referred to as "
filler episodes," being outside of the canon of their source material. ==Additional works==