Apollo Justice: Ace Attorney (Japanese: Gyakuten Saiban 4) is a courtroom adventure video game developed and published by Capcom. It is the fourth installment in the Ace Attorney series, and the first to be released on the Nintendo DS. The game follows rookie attorney Apollo Justice as he investigates and defends cases for his clients in the court of law. Players explore crime scenes and collect evidence, then present it in court to prove their client's innocence. During court sessions, players cross-examine witnesses and use evidence to expose contradictions in their testimony. The game also introduces the 'Perceive' system, which allows players to spot subtle changes in a witness's demeanor as they present their evidence. Apollo Justice: Ace Attorney is a unique and engaging adventure game, and is sure to please fans of the series.