Fate/Zero is a Japanese light novel written by Gen Urobuchi, illustrated by Takashi Takeuchi. It is a prequel to all routes in Type-Moon's visual novel, Fate/stay night.
See also: Fate/stay night, List of Fate/Zero episodes, List of Fate/Zero characters, Saber (Fate/stay night), Fate/stay night: Unlimited Blade Works (TV series), and List of Fate/stay night characters.