The King of Fighters (KOF) is a Japanese fighting game series by SNK that began with The King of Fighters '94 in 1994. The series was developed originally for SNK's Neo Geo MVS arcade hardware. This served as the central platform for the series until 2004 when SNK retired it in favor of the Atomiswave arcade board. Two King of Fighters games were produced for the Atomiswave platform (The King of Fighters Neowave and The King of Fighters XI) before SNK discontinued using them for the series. The series' most recent arcade hardware is the Taito Type X2, first used with the release of The King of Fighters XII. Ports of the arcade games and the original The King of Fighters games have been released for several video game consoles. The latest entry in the series, The King of Fighters XV, was released in February 2022. The game's story focuses on the title tournament where fighters from multiple SNK games take part. SNK also created original characters to serve as protagonists from each of their story arcs while still interacting with fighters from Art of Fighting and Fatal Fury, among others. Multiple spin-off games, such as the R duology for the Neo Geo Pocket and Maximum Impact for the PlayStation 2, for example, have also been released. There have been multiple cross-over games where the SNK cast interacted with characters created by Capcom, while some characters have been present as guest characters in other games, such as Mai Shiranui in the Dead or Alive games, Geese Howard in Tekken 7, Kyo Kusanagi in Fighting Days, Kula Diamond in Dead or Alive 6, and Terry Bogard in Fighting EX Layer and Super Smash Bros. Ultimate. The King of Fighters was originally conceptualized as a side-scrolling beat 'em up until SNK changed it to a fighting game that took its subtitle from the first Fatal Fury game: Fatal Fury: King of Fighters. Though originally released yearly from its first inception, the company decided to take more time to develop its games after 2004. Critical reception of video games has been generally positive with their use of teams and balanced gameplay often cited.