Canon

Canon refers to all official and undeniable information within a general series. Originally a religious term used to refer to which scriptures written "counted" in a religion, the term has expanded to have meaning in fictional continuities as well.

In the Pokémon franchise there are several canons, usually sharing elements and concepts among them, most notably the existence of. Aside from this and the interrelation of the various species of Pokémon (such as by evolution), these worlds can vary from one another in canon and storyline either very little or very greatly.

Canon is different from fanon in that, while fanon things may be mutually agreed upon by most, and possibly all, fans, they are never officially stated.

Games
The canon of the core series consists of the following:
 * Events occurring in the core series games are the ultimate canon.
 * Choices made by or for player characters, such as the hero's gender and starter Pokémon, are generally not fixed within the canon, with the exception of from the Generation I games and . In appearances in later games, Red possesses all three of the original starters as well as.
 * Different versions of a game all occur in parallel universes. Both and  are canon, but occur in different universes.
 * Content from side series games, such as Pokémon Colosseum and Pokémon XD: Gale of Darkness, is canon to the core series unless it conflicts with events in the core series games. Content from spin-offs, such as the Pokémon Mystery Dungeon series, is generally non-canon.
 * Canonical material may also be found in related media, like animated trailers, manuals, or merchandise.

Anime
The canon of the Pokémon anime consists of the following:
 * The events of each and every episode are canon, and occur in chronological order with the exception of EP052, which takes place before EP049. Also, the special episodes Holiday Hi-Jynx and Snow Way Out! (originally postponed after EP038 caused seizures in some viewers) take place either directly before or after EP039. Three unaired episodes (one in the and two in the ) are not canon.
 * All movies up to Pokémon the Movie: I Choose You! are canon to the TV series (although only one of the two versions of the 14th movie is canon), and usually act the same as filler episodes, as and  do not obtain, evolve, or release any Pokémon, and do not earn any Badges or Ribbons. Often, a movie takes place chronologically between the episodes between which it premieres in Japan.
 * Pokémon the Movie: I Choose You! establishes a new canon that is followed by The Power of Us.
 * The Japanese version of the anime supersedes any and all dubs if there is conflict between them, unless the dub corrects an obvious error. If something is said in a dub that is not mentioned in the original, it may or may not be canon.
 * Some of the Pikachu shorts, as well as three special episodes and two animated shorts based on Pokémon Mystery Dungeon spin-off games are not part of main anime's canon.
 * Pokémon Origins, Pokémon Generations, and Pokémon Black Version 2 and Pokémon White Version 2 and Pokémon Omega Ruby and Pokémon Alpha Sapphire Animated Trailers are not part of the main anime's canon but are instead their own canons.

Manga
The canon of the various Pokémon manga consists of the following:
 * Each manga series is a separate canon, except in the case of sequels, such as Pokémon Chamo-Chamo ☆ Pretty ♪, which follows from Magical Pokémon Journey.
 * Pokémon Adventures chapters and rounds follow chronologically from one another, rather than having the and s occur contemporaneously to the  and s as the storylines of the games they are based on do. The same applies to  and s which do not occur simultaneously with the . The exceptions to this rule are the  and s, both of which occur between Emerald and Diamond & Pearl. Although the rounds of a chapter follow chronologically from one another there are few exceptions to this. For example, Buzz Off, Butterfree! (round 152) takes place simultaneously with Slugging It Out With Slugma (round 117).
 * Pokémon Ranger the Comic: Double Mission and by extension, Darkrai Mission Story: Pokémon Ranger Vatonage - the Comic, although not strictly related, are canon within Pokémon Adventures, as evidenced by The Final Dimensional Duel XI.

Differences between canons
Characters that are well known in the Pokémon franchise can have vast differences between the various canons. For example, in the games, Brock is a well-known Gym Leader, the toughest Trainer in the area of Pewter City, and remains as the leader of its Gym between the time of /'s journey and //'s. In the anime, however, while is a tough Trainer, his true calling is as a  (and later on, a Pokémon ), and he took the mantle of Pewter Gym Leader only because both of his parents left on their own Pokémon journeys, leaving him in the care of the Gym and their rather large family. Differences can go much further than that, with Sabrina being a kind shrine maiden in The Electric Tale of Pikachu, a misguided young woman due to the development of her powers in the anime, and a Team Rocket member in Pokémon Adventures.

Canone