Gyakuten Saiban Jiten (逆転裁判事典, lit. "Turnabout Trial Encyclopedia") is an encyclopedia of sorts for the first three games in the Ace Attorney series, as well as the DS-exclusive case from the original game (Rise from the Ashes). It was released for the Nintendo DS as a part of the Japanese Limited Edition version of Gyakuten Saiban 4 (Apollo Justice: Ace Attorney), and contains character profiles, evidence lists, character animations, opening cinematics, background images, music from the game, and so on. It did not see an international release.
The main objective of the game is to read information about the cases from the first three games in the series. Each section in the encyclopedia details information about each case (i.e., case synopses, character profiles, and location information), with a particular section being unlocked after being viewed in the index page, which contains a list of all the sections for easy viewing. As sections are unlocked, the game's completion percentage in the index page will increase. Other features include a library of background music from each game and a gallery of each character's animations (including some animations that were cut from the final game).
Hidden content is unlocked on completing a certain percentage of the encyclopedia: 30% will unlock all of the opening cinematics, 60% will allow the player to view all credit sequences (including Rise from the Ashes), 90% unlocks all breakdown animation sprites for each episode's culprits and 100% unlocks a gallery of all the still images used in the games.
- In the background music section for Gyakuten Saiban 3 (Phoenix Wright: Ace Attorney: Trials and Tribulations), some tracks are missing "instruments" that were present in the DS version. A notable example would be "Pursuit ~ Cornered 2004". As Gyakuten Saiban Jiten was released four months before the Nintendo DS version of Gyakuten Saiban 3, it is possible that these tracks may have been ported from the Game Boy Advance version.