- Two bits of common fanon in the Ace Attorney fandom would be calling Manfred von Karma the "Demon God" Prosecutor and that the reason Manfred adopted Miles Edgeworth was partly for an heir, this coming from his aristocratic attitude. Of course, this makes no sense given that canonically Von Karma explicitly screams that he always hated Edgeworth for scarring his arm with the misfired gun during the incident that led to Von Karma murdering his father and taking in Edgeworth in the first place. The reason he took him in was to set up a Evil Plan to ruin Edgeworth's life by making him believe he murdered his own father instead of Von Karma.
- Despite the lack of voiced dialogue except for the Stock Audio Clips, the fandom collectively decided that Edgeworth speaks using Received Pronunciation, though he is an American raised by a German (and his Japanese counterpart is, well, native to Japan, but raised by an American).
- The Ace Attorney Kink Meme also has its own fanon, like OCs which are used by different users for different stories, and when a story centers around a pairing other than the usual popular ones, it will normally be taken for granted that the series doesn't really have a canon on shipping... just a lot of Ship Tease.
- Do NOT try to claim that WrightWorth (or Narumitsu in Japanese) isn't canon and Phoenix and Miles are Just Friends. It is easily the most beloved pairing in the franchise despite them never openly showing physical affection or outright stating their feelings for one another. Capcom does not help because they appear well aware of its popularity and love to play up their romantic subtext in both the games and the anime.
- Klavier and Kristoph Gavin's father is often assumed to be named "Kurtis". This isn't canon but it shows up in multiple fan works.
- In the Apollo Justice era, Edgeworth is assumed to wear glasses. This has now become canon as of Dual Destinies. The jury's still out on whether it's Ascended Fanon or I Knew It!, though.
- Players of Dual Destinies often come to the conclusion that the Phantom murdered Bobby Fulbright so that he could take his identity. In canon, it's never revealed how Fulbright died, only that his body couldn't be identified until the closing hours of Case 5-5.
- As of Spirit of Justice, Gumshoe is one of the only classic trilogy recurring characters who hasn't appeared post-Time Skip. Fanon usually has him in some not-insignificant position in the police department (sometimes even as chief) and married to Maggey.
Fanon / Ace Attorney