Chaos;Head (stylized as ChäoS;HEAd) is a 2008 science fiction visual novel video game developed by 5pb. and Nitroplus. It is the first game in the Science Adventure series. Following the original Windows release, the enhanced version Chaos;Head Noah was released for Xbox 360 in 2009, and has since been ported to multiple platforms. An English localization was released by Spike Chunsoft for Nintendo Switch and Windows in 2022. The game follows Takumi Nishijou, who gets involved in the "New Gen" serial murder case. He frequently experiences delusions and hallucinations, some of which the player can influence, which affects the progression of the story.