>>64393402The game explains most of what you need to, but the basic gist is:
There's a magical cup. Everybody wants the magic cup, because it'll grant you any wish. So people that can use magecraft (mages), constructed a battle royale ritual (Grail War) in order to summon the magic cup. They summon historical/mythical figures (Servants) and form contracts with them (the winning Servant also gets a wish) in order to become a duo that competes against all the other Servant/Master pairs. There are seven Servant classes that are summoned in a Grail War: Saber, Lancer, Archer, Rider, Assassin, Caster and Berserker. That's basically all you need to get started.
