Canon

Canon is a fan-based idea that exists in a unique way within Doctor Who fandom. In theory, it means a body of work that an established body of literature that can draw upon, but it is more commonly thought as what a fan considers what forms part of the Doctor Who universe, or what "really happened". Despite this being a personal choice, it has been discussed and argued about in practically every Doctor Who-related forum or message board that has existed on the internet.

Unlike the Star Trek and Star Wars universes, the British Broadcasting Corporation has never made a pronouncement about what is or is not canon for Doctor Who. Shortly after he brought Doctor Who back to television in 2005, Russell T Davies specified that canon "is a word which has never been used in the production office, not once, not ever". Similarly, at a 2008 San Diego Comic-Con panel, Steven Moffat remarked, "It is impossible for a show about a dimension-hopping time traveller to have a canon." Even when specifying that the television show was going to contradict certain revelations about Time Lord history and biology from the Virgin New Adventures, Moffat declared that those novels were "a separate (and equally valid) continuity".

The only exception to this is in regards to video games: in August 2010, a BBC press release stated that, in Doctor Who: The Adventure Games, "Players will encounter new and original monsters, in stories which form part of the overall Doctor Who canon". Similarly, in July 2018, BBC Studios announced that, with games like Doctor Who Infinity, they would be "taking content from our major brands and delivering gaming experiences that actually form part of the canon. It's not led from TV series it comes to the game first."

A large issue when attempting to construct a definition of canon for Doctor Who is that it is never finished; between its many stories across practically every medium, Doctor Who has been in more or less constant production in one way or another since 1963. Some fans may want a complete narrative, but Doctor Who can never be complete.

Narrative history
Canon can be defined as the cultural/narrative history of Doctor Who, in that everything Doctor Who, from the annuals to the audio stories, including their ideas and their histories, becomes part of the larger Doctor Who universe. Writers frequently reference or are influenced by this body of works while creating new stories. This can also be seen as continuity, which is, roughly speaking, the interconnectedness of stories and how they are referenced in each story.

As a narrative history, the fact that it exists is enough to consider it canon, and elements might make their way into future productions. The Dalek spacecraft of The Dalek Chronicles were worked into CGI replacement shots on the DVD of The Dalek Invasion of Earth, and then further into television stories such as The Parting of the Ways. Again, this in an example of continuity within the show rather than as an established canon.

Competing narratives
Throughout Doctor Who's production there have always been "competing narratives": stories produced across several mediums that used the TV-created characters. In the 1960s and '70s, these took the form of short stories and comic stories produced in annuals and comic strips. In the 1980s, Doctor Who Magazine joined the fray with their own comic strip based stories, and, in the annuals, short fiction is also produced for the magazine.

During the 1990s, Doctor Who as a brand shifted and fragmented with the end of television production, with multiple Doctor Who spin-offs produced by fans and novel series published by Virgin Books continuing the Doctor's travels beyond its TV realm. Concurrently, the TV series was analysed in detail, with academics unearthing long undiscovered materials about the genesis of the show. Official history of the Doctor Who series was greatly expanded upon within a postmodern context.

Other universes
There have been deliberate moves to create separate canons of Doctor Who, the earliest examples of which are the two movies of the 1960s starring Peter Cushing. Dr. Who and the Daleks and Daleks' Invasion Earth 2150 A.D. make no effort to be a part of the "established canon", with none of the Doctor Who elements, aside from the police box and the Daleks, appearing in their accepted form. These stories, however, still "exist" and have not been ignored by even the BBC, with a short story appearing in the BBC Books short story anthology Short Trips and Side Steps featuring Dr Who.

Other examples are evidenced with an official shift in definition; 2003's Scream of the Shalka was to have been the continuation of Doctor Who, with Richard E Grant promoted as the "new" Ninth Doctor. The BBC's first edition of Doctor Who: The Legend even has several pages which details the "Ninth Doctor". But this detail was changed, and the "Shalka Doctor" shifted away from "canon" with the arrival of the new BBC Wales series in 2005.