The Fuyuki Holy Grail grants a total of twenty-one Command Spells in each war. Masters obtain three Command Spells, and Servants have no choice but to cooperate with their Masters due to their hold over them. Depending on the nature of the Servant, such binding is not necessary, while others may slay their Master instantly should all three be lost. They disappear as they are used up, and it can be said that a Master who uses up all three loses authority over their Servant. Even if a Master contracts with multiple Servants at once, they will only be given a total of three Command Spells that can be used on any contracted Servant. It is possible to steal more from other Masters or receive more from the overseer depending on circumstances, and it is also possible that anyone interfering with