Canon AU

Canon AU is a term that can have different meanings depending on context.
The term has two common definitions:
# an AU that originates within the commercial source work itself, which can include dream worlds created by magic or other means, as in the musical episode of Supergirl and the Bones episode The End in the Beginning
# a fanwork AU that diverges relatively narrowly from that of its source work. the change may be limited to a particular event or character so that the canon story is still recognizable as the changes are explored. Alternate Canon refers exclusively to these types of works, and they have significant crossover with the Canon Divergence AU genre.
The different meanings of the term can lead to confusion, for example on multifandom archives or bookmarking sites when fans who understand it to mean a fanwork AU that diverges relatively narrowly from that of its source work tag fanworks with the same term other fans use to tag a fanwork set in a canonical alternate reality. See Canon Divergence AU and Canon AU tags on AO3.
==Fandom-specific popularity==
Fandoms with different universes within the canon of the commercial source work itself (for example the universes seen through the Quantum Mirror in SG-1, the Vegasverse in SGA, the Wishverse in BtVS, the Mirrorverse in Star Trek) sometimes refer to these universes as Canon AUs. Fanworks based on these source-canon AUs (a.k.a. canon "Alternate Realities") may be labeled in various ways as well, sometimes using source-canon episode titles, and sometimes coining new terms, such as: 
* In Stargate Atlantis fandom, Mensaverse or Mensa AU denotes works spun off from the episode McKay and Mrs. Miller (so named because of a glancing reference to the John Sheppard of the alternate reality being active in Mensa). 
* In Xena fandom, Conqueror tags stories set in the world of the Hercules episode Armageddon Now.
* The Marvel universe is a multiverse. See List of Marvel Universes 
* in Lois and Clark fandom, Alt-Clark refers to works based on the AU shown in the episode Tempus, Anyone? and its sequels, showing an alternate Clark who lost his adopted parents early, never met his world's Lois, and was unmasked as Superman shortly after canon Lois met him and persuaded him to start using his powers.
*The "Djinnverse," "It's a Terrible Life (Smith/Wesson)" verse, or "The French Mistake" verse from Supernatural 
In Merlin fandom, Canon AU means an AU set in the Canon Era of the fantasy Camelot setting, distinguishing them from "modern AU" works. This can include stories where Arthur Conquers Ealdor, Merlin came to Camelot earlier or later than in canon, they meet under different circumstances but Merlin still ends up as Arthur's manservant, Merlin is an enemy sorcerer (who becomes an ally or enslaves Arthur) or they find themselves in a marriage of convenience to bring peace to the land. Fusions with other fantasy sources can also be Canon AUs in Merlin fandoms. See :Category:Merlin Canon AU for example fanworks.
==External Links==
*Alternate Universe - Canon works on Archive of Our Own
*Alternate Canon works on Archive of Our Own
*Recs tagged Canon Alternate Realities at Fancake
Category:Merlin Tropes & Genres
Category:Tropes & Genres