The SNK vs. Capcom (or alternately Capcom vs. SNK) series is a collection of video games by either Capcom or SNK featuring characters that appear in games created by both companies. The "vs. series" terminology originates from the fact that many of these games (but not all) are fighting games.
The supposed origin behind this series was an issue of Arcadiamagazine in which there were articles covering both The King of Fighters '98 and Street Fighter Alpha 3, both of which were released at around the same time. Readers had misread the cover, which said KOF vs. SF, to mean that there was a fighting game that would pit characters from Street Fighter and The King of Fighters. Because of this uproar, Capcom and SNK supposedly signed a deal that would allow them to produce only two fighting games concerning both franchises in 1999 (the Card Fighters series (see below) were not fighting games and therefore were exempt from the rule). It is highly suggested[by whom?] that SNK vs. Capcom: SVC Chaos was only made in order to fulfill the contract obligations that SNK made prior to the company filing bankruptcy and their eventual closing in 2000. Also, if one company was the main creator of one game, the distributing company would gain the profits and not the company that licensed the characters for use (although SNK gave the rights to use the SNK characters to Capcom for the first Capcom vs. SNK game, SNK did not profit from the game, which did not help their financial problems). There were interviews with SNK that it would be possible to renew their contract with Capcom to make new SNK vs. Capcom games, but in another interview, both companies stated that they would not do any further collaboration with each other. SNK vs. Capcom: Card Fighters DS will probably be the last crossover game between both companies. However, in an interview from January 2009, Yoshinori Ono, the producer of Street Fighter IV, expressed interest in a possible third game if fans demand it.
Capcom vs. SNK: Millennium Fight 2000 - Released for Sega's NAOMI arcade hardware in 2000 and ported to the Dreamcast during the same year, the original Capcom vs. SNK features 28 characters (evenly divided between Capcom and SNK properties), two selectable fighting styles or "grooves" (based on the gameplay systems featured in the The King of Fighters and Street Fighter Alpha series) and a ratio-based character selection system that determines the number of characters in a player's team based on their strength.
An updated version titled Capcom vs. SNK Pro, released for the arcades and Dreamcast in Japan and ported to the PlayStation in 2001, which adds Dan Hibiki and Joe Higashi to the character roster (they originally appeared only in the ending sequence of the original game). The Dreamcast version of the game also discards the shop option to earn extra characters and colors, having all of them available by default.
Capcom vs. SNK 2: Mark of the Millennium 2001 - Titled Capcom vs. SNK 2: Millionaire Fighting 2001 in Japan. Released for the NAOMI hardware in 2001 and ported to the Dreamcast (in Japan only) and PlayStation 2 during the same year. The game expands on the "Groove" system from the previous game by featuring six different fighting styles or "Grooves" and adds twelve new characters in addition to the ones featured in Capcom vs. SNK Pro.
The GameCube and Xbox versions were released under the title of Capcom vs. SNK 2 EO. According to the Japanese official website for the GameCube version, EO stands for Easy Operation, because of a new feature that allows the player to assign special techniques to the right analog stick (C Stick for the GameCube version).
SNK vs. Capcom: Card Fighters Clash - Also released for the Neo Geo Pocket Color, a collectable card game featuring trading card based on SNK's and Capcom's properties. Two versions were produced; the SNK Supporter's Version and the Capcom Supporter's Version.