Kamen Rider × Kamen Rider W & Decade: Movie War 2010 (仮面ライダー×仮面ライダーW（ダブル）&ディケイド MOVIE大戦2010, Kamen Raidā × Kamen Raidā Daburu Ando Dikeido Mūbī Taisen Nisenjū) is the commercial promotion for theatrical releases of the Kamen Rider Decade epilogue film, the Kamen Rider W flashback film, and a third film that serves as a crossover between the two and finale to Decade (all directed by Ryuta Tasaki). Unlike subsequent Movie War films, this film focuses more on Decade than W. The films were released on December 12, 2009.

Movie War 2010 is split into three parts. The Kamen Rider Decade segment, written by Shōji Yonemura and titled Kamen Rider Decade: The Last Story (仮面ライダーディケイド～完結編～, Kamen Raidā Dikeido ~Kanketsuhen~), follows the series' cliffhanger, "Destroyer of Worlds", is billed as the "True Ending" (本当の終わり, Hontō no Owari), and was originally subtitled Decade vs. All Riders (ディケイド対オールライダー, Dikeido Tai Ōru Raidā). The Kamen Rider W segment, written by Riku Sanjo and titled Kamen Rider W: Begins Night (仮面ライダーＷ（ダブル）～ビギンズナイト～, Kamen Raidā Daburu ~Biginzu Naito~), takes place between episodes 14 and 15 of the series and investigates the origins of the titular characters. Additionally, this film is described as the "True Beginning" (本当の始まり, Hontō no Hajimari) and was originally subtitled Episode Zero (エピソードゼロ, Episōdo Zero). The final segment, Movie War 2010 (MOVIE大戦2010, Mūbī Taisen Nisenjū), is a crossover of the two films that brings the casts and characters of Decade and W together to finish the fight with Super Shocker together.