Master Chief Petty Officer John-117, or "Master Chief", is a fictional character and the protagonist in the Halo multimedia franchise. Master Chief is a playable character in the series of military science fiction first-person shooter video games Halo: Combat Evolved, Halo 2, Halo 3, Halo 4, Halo 5: Guardians and Halo Infinite. The character also appears in Halo books and graphic novels – including Halo: The Fall of Reach, Halo: The Flood, Halo: First Strike, and Halo: Uprising.