Fate/stay night chronicles a two-week period in the life of Shirō Emiya, an amateur mechanic who attends school called Homurabara Gakuen in Fuyuki City. Ten years ago, Shirō was caught in a massive fire hazard that incinerated his parents and consumed a large portion of the city; as he was dying, an enigmatic man discovers and treats him. This man, Kiritsugu Emiya, decides to adopt him, though the two maintain a distant relationship because of Kiritsugu's frequent departures from Fuyuki City. One moonlit night, Kiritsugu and Shirō had a discussion outside of their home, and Shirō discovers a fact about his father that Kiritsugu was actually a mage.
聖杯):傳說中可實現持有者一切願望的寶物。而為了得到聖杯的儀式就被稱為聖杯戰爭。
參加聖杯戦爭的7名由聖杯選出的魔術師被稱為御主(マスター,英文Master),與7名被稱為從者(日文:サーヴァント;英文Servant)的使魔訂定契約。他們是由聖杯選擇的七位英靈,被分為七個職階,以使魔的身份被召喚出來。
能獲得聖杯的只有一組,這7組人馬為了成為最後的那一組而互相殘殺。
基本沒有學習魔術的才能的魔術師主角衛宮士郎,偶然地與從者中的劍士·Saber(セイバー)訂定契約,被捲入聖杯戦爭當中。 fate線中,衛宮士郎發現自己愛上自己召喚出來的從者Saber,但最後卻因為為了破壞聖杯而用掉最後的令咒而失去Saber 。