Detective in the court game
In Phoenix Wright: Ace Attorney, the player takes on the role of Phoenix Wright, who must do various tasks, some being standard operation for a defense attorney and some having nothing to do with the profession. Except for the first case, the game cycles between two phases: Investigation, and Courtroom Sessions. Investigation phases consist of gathering clues that will be needed to prove a client's innocence, while courtroom phases consist of cross-examining witnesses and presenting evidence. The new episode takes advantage of the DS's features at several points, such as spraying luminol with the touch screen to locate blood stains at crime scenes, dusting for fingerprints, or examining a three-dimensional view of evidence.
The first case of the game presents defense attorney Phoenix Wright at his first trial under Mia Fey's watchful eye, successfully defending his childhood friend Larry Butz for murder. However, in the game's second case, Mia is murdered for being aware of corporate blackmail, and her younger sister Maya Fey is charged with the crime because her name was found on a piece of evidence. While defending her, Phoenix is reintroduced to another childhood friend, Miles Edgeworth, who is the prosecutor for Maya's case and has established himself as a "genius" for the prosecution system. Maya is found not guilty of the crime, and becomes Phoenix's assistant in further cases, offering her channeling ability as a "Spirit Medium" of Kurain village to bring the spirit of Mia to help at critical times. Phoenix and Miles find that while they have their friendship from their youth, they continue to face off against each other in the courtroom.
In one case, Miles is charged with murder, and Phoenix steps up to defend him. It is discovered that Miles was set up by his old mentor, Manfred von Karma, who several years before had shot and killed Miles' father (which a young Miles witnessed while they were trapped in an elevator after an earthquake, though Miles had thought he himself had done it) for ruining Manfred's perfect record in court, and who was making sure that all those that knew of this were dealt with. Phoenix is able to expose Manfred's cover-up and achieve a "not guilty" verdict for Miles. After the case, Miles thinks about taking time off from his position to consider the events, while Maya announces she is going back to her home in Kurain Village to train more.
The fifth case, exclusive to the DS version, has the scientifically-minded Ema Skye begging Wright for help to defend her older sister Lana, who claims she murdered someone. Using Ema's scientific help to establish evidence and the surprising prosecution help of Miles during the trial, Phoenix is able to learn that Lana Skye was blackmailed by the Chief of Police Damon Gant into covering for a murder she thought that Ema had committed several years before, labeled the SL-9 Incident (the common name among civilians in the game is "The Joe Darke Killings"), when in actuality Damon himself had committed it and pinned the blame on Ema.
The five cases within the game are:
The First Turnabout
Phoenix defends Larry Butz for the murder of his girlfriend Cindy Stone. Cindy was killed by Frank Sahwit when he was caught stealing Cindy's items. He panicked and struck her with "The Thinker," a precious item Larry had made for Cindy. This is Phoenix's first trial.
Phoenix defends Maya Fey for the murder of her older sister Mia. Mia Fey was really murdered by Redd White with the help of his assistant Mrs. April May (she gave a false testimony to implicate the defendant). Redd struck Mia with the item Larry gave her after the first case, "The Thinker." Redd also forged evidence by writing Maya's name in blood in an attempt to frame her. Later, when Phoenix manages to track him, Redd pins the murder on him. Phoenix has to defend himself in court, but manages to turn the tables and prove that Redd was the one who murdered Mia.
Phoenix defends the actor Will Powers for the murder of co-star Jack Hammer, who was really murdered by Ms. Dee Vasquez. Ms. Dee Vasquez pushed Jack Hammer off the stairs to his death when he fell on top of sharp garden spikes at the bottom of the stairs. Dee Vasquez and the director of the Steel Samurai, Sal Manella, changed the appearance of Jack Hammer's body so it looked as if Will Powers had killed him. It was revealed Jack Hammer did this to someone else five years ago.
Phoenix defends Miles Edgeworth for the murder of a key attorney involved in the murder case of Miles' father, labeled as the DL-6 Incident. Yanni Yogi turned out to be the real murderer of Robert Hammond who shot him to death after his tragic past. However, Edgeworth protested against his innocence and asks to be tried for the DL-6 Incident. It is revealed that Manfred von Karma killed Miles' father, after Edgeworth accidentally shot him in the shoulder.
Rise from the Ashes
Phoenix attends Ema Skye's request to defend her sister Lana in a murder charge, despite her claims of guilt. Bruce Goodman wasn't killed by Lana, but by Damon Gant in the Evidence Room, who then got Lana Skye (with blackmail) to help him get rid of the body, Lana Skye changed the evidence everywhere so it made her look like the murderer of Bruce Goodman.