Saber (セイバー), Knight of the Sword and Heroic Spirit of the Sword, is one of the Three Knight classes among the seven standard Servant classes summoned for the Holy Grail War. Servants placed within this class are agile and powerful melee warriors adept at swordsmanship, boasting high ratings in all categories, and they are often heroes from the Age of Gods when magecraft was still commonplace. The qualifying conditions require the Heroic Spirits to have legends as knights of the sword, and it is the class that requires the highest levels of attributes in all but the Magic attribute.
The standard opinion is that the Saber class is best of the seven classes and the strongest of the Servants, said to have made it to the final battle in the first four Fuyuki wars. They will generally have an overwhelming advantage over Caster-class Servants who use magecraft as their main offensive ability due to their Magic Resistance The weakness of the class is its straightforwardness in battle, only able to attack the enemy with their sword while unable to resort to other tactics like the Presence Concealment of the Assassin Class.