The Japanese adult visual novel Fate/stay night features a number of characters created by Type-Moon, some of whom are classified as Servants with special combat abilities. The characters listed have appeared mainly in two anime television series adaptations with a movie trilogy adaptation produced by Studio Deen and Ufotable respectively, and it's visual novel sequel, Fate/hollow ataraxia. A Fate/stay night: Unlimited Blade Works animated film was released prior to its TV series.

Fate/stay night is a Japanese visual novel game developed by Type-Moon for Windows on January 30, 2004. Initially released as an adult game, a version titled Fate/stay night Réalta Nua, which replaced the sexual content with extensive visual and narrative elements, completed the story with an ending scene, and featured voice actors from the 2006 anime series, was released on April 19, 2007 for the PlayStation 2. It was later ported to Windows in 2011, PlayStation Vita in 2012, and iOS and Android in 2015. A remastered version of Réalta Nua is set to release for Nintendo Switch and PC via Steam in 2024, marking the first time the game will be available outside Japan. The plot focuses on a young mage named Shirou Emiya who becomes a warrior in a battle between "Servants" known as the Holy Grail War. Shirou bonds with a heroine through each route and confronts different adversaries participating in the war. The author, Kinoko Nasu, summarised Fate/stay night as:"...the story about legendary heroes and 'a boy meets a girl.'... The main theme is 'conquering oneself.' There are three story lines in Fate, each has a different themes. The first one is the 'oneself as an ideal.' The second one is 'struggling with oneself as an ideal.' The third one is 'the friction with real and ideal.' This game is describing the growth of the main character Emiya Shirou. The first storyline shows his slanted mind, the next storyline shows his resolve, and the last storyline gives another resolution for him as a human. All three storylines are essentially equal, but they have different forms."