Ansatsuken

is a Japanese neologism used frequently in fictional works to describe any martial art style or fighting technique that has been developed with the purpose of killing an opponent. The term is used interchangeably as well and the homophonous term  is used when the martial art style or technique explicitly revolves around swordsmanship rather than barehanded combat.

Examples in fiction

 * Hokuto Shinken from the Fist of the North Star franchise, which is described as an "assassination art passed down from one master to a single successor" (一子相伝の暗殺拳). The term ansatsuken has also been applied as well to other fighting styles in the series, particularly Nanto Seiken, Gento Kōken and Hokuto Ryūken (see list of fighting styles in Fist of the North Star).
 * Tenshū, Suichū and Chishū, the three sons of Zekū in Ironfist Chinmi, are collectively known as the "Three Brothers of the Assassination Fist" (暗殺拳の三兄弟), as each of them are proficient in their own assassination styles: Hangetsuken (半月拳), Sentōken (旋刀拳) and Ryūsōken (龍爪拳) respectively.
 * Street Fighter: Ansatsuken (ストリートファイター 暗殺拳) is a live-action feature film. It depicts the fighting style used by Street Fighter characters Ryu, Ken, Akuma and Gouken is described as a "martial art rooted as an assassination art" (暗殺拳をルーツとした格闘術). Although Ansatsuken is a general term in Japanese, it has been used in the English language edition of Street Fighter: Eternal Challenge and other English-language Street Fighter media specifically as the name of Ryu and Ken's fighting style which is heavily based on striking-based martial arts such as Karate and Kempo. Though not a mistranslation, it likely stems from a wrong understanding of the usage of the term when converted to the English media from the Japanese sources.
 * Gen from the Street Fighter series employs two assassination styles, Mourning style (暗殺拳・喪流) and Hateful style (暗殺拳・忌流).
 * The Twin Tailed Scorpion Fist (双尾蠍拳) used by El Gado in Final Fight Revenge.
 * The Shadow Dragon Fist (魔竜拳) in Lunar: Eternal Blue.
 * Gensatsuken (幻殺拳) used by the Mysterious Warrior in the NES version of Double Dragon II: The Revenge. In Double Dragon Advance, this style is renamed Gensetsuken (幻截拳) and its now used by a group called the Five Emperors.
 * The Japanese language edition of Avenger!, the first book in the Way of the Tiger series, is titled Tiger Ansatsuken (タイガー暗殺拳).
 * The character Myousai Kakouen in Ikki Tousen has been described as a "master of the assassination fist" (暗殺拳の使い手).
 * The character Kuzuki Soichiro in Fate/stay night uses a rare martial arts technique known as Hebi (蛇).
 * Kenichi: The Mightiest Disciple has "Satsujinken" as the main opposition to the protagonists. It's a principle followed by warriors who do not hold back in a fight and aim to kill their opponent, as they believe martial arts were created for this purpose.