NFL 2K is an American football video game series developed by Visual Concepts and published by Sega. Based on the National Football League, the series was originally exclusive to Sega's Dreamcast video game console. It is the very first '2K' game ever released and therefore the beginning of a running athletics series which has since spawned 2K Sports as a devoted publisher. After the Dreamcast was discontinued, the series continued to be published for other sixth generation game systems and became the chief competitor of EA Sports's Madden NFL series. However, after the competitively priced NFL 2K5 significantly reduced sales of that year's Madden release, EA signed an exclusivity deal with NFL that made Madden NFL the only series allowed to use NFL team and player names. After losing the NFL license, Visual Concepts made a brief return to developing football games with the release of All-Pro Football 2K8, which featured former NFL players.