Will is one of the six base attributes assigned to characters based on their class. The Will attribute represents a character’s mental fortitude or mettle, and affects the character’s maximum MP and the rate at which their MP regenerates.
Classes like Chanters and Clerics, who rely on MP to keep themselves and others alive, will have more Will than classes like Rangers and Assassins, who use much less MP in comparison and can still be effective with little to no MP.
During character creation, characters are assigned a default value of the Will attribute based on their class. When a character ascends at level 10, their Will attribute can increase or decrease based on their chosen sub-class. However, external to character creation and ascension, the Will attribute cannot be increased or decreased.