The Willpower trait is used in all games of the Storyteller System, Revised Storyteller System and Storytelling System. Willpower is rated from 1 to 10, and has both a permanent rating (or score) and a pool of temporary points.
Permanent Willpower indicates a character's overall determination and strength of personality. Average humans generally have ratings between 3 and 5; only a rare few, usually fanatics, have a Willpower higher than 7. Most Classic World of Darkness games illustrate the scale of Willpower using the following descriptors:
In the Storyteller System, Willpower is an independent trait and may rise and fall regardless of a character's Attributes or other Advantages. Different character types figured their minimum Willpower scores using different means: Kindred, for example, used their Virtues to determine their starting Willpower, whereas for Hunters it was decided by their Creed.
In the Storytelling System, Willpower is a derived trait, with a character's maximum score determined by their Resolve and Composure Attributes. Willpower may only be raised by raising these Attributes, though Willpower may fall below the maximum rating (see below). In such cases, it must be raised independently back to the maximum.
Willpower dots may be spent in some games, representing a permanent sacrifice of a character's mental power. This is typically used to achieve a permanent magical effect: making an illusory object real, siring a new vampire (in Vampire: The Requiem), or crafting one's soul to join a Legacy.
It is also possible to lose Willpower dots unwillingly; this is usually due to supernatural misadventure (like a curse or botched use of Thaumaturgy), but may also result from torture, psychological abuse, or possibly extreme psychiatric treatment (e.g. lobotomy).
Whereas permanent Willpower encompasses a character's drive in general, temporary Willpower indicates her current state of mind. A character whose temporary Willpower points equals their permanent Willpower rating is energetic (or at least upbeat) in relation to his normal mood, while a character with only a single Willpower point left is downright lethargic. Having no willpower points often indicates complete mental and emotional exhaustion. Under normal circumstances, a character may not have more temporary Willpower points than her permanent Willpower rating; some games and specific rules systems do allow for higher numbers of points, but this rarely, if ever, exceeds a maximum of 10 points.
Temporary Willpower may often be spent for a bonus on a roll, representing a notable dedication to a specific task. In most Storyteller system games, this granted an automatic success, while in Exalted, Scion and Storytelling System games it grants bonus dice to the roll. It may also be spent to empower certain kinds of magic (like Thaumaturgy or Pledges), to resist natural or unnatural urges or compulsions, or even to prevent supernatural mind control. Such expenditure is not always voluntary: characters who choose or who are forced to act against their instincts or judgement may be required to use up Willpower points to do so. This is especially true of character types who suffer from supernatural compulsions, for example vampires and werewolves, who must struggle against their predatory natures, and Exalts, who suffer under variations of the Great Curse.
When rolling Willpower, the permanent trait is used.
Willpower points are generally regained through proper rest, or by accomplishing tasks which reaffirm one's essential nature. This is achieved in Storyteller System games by acting in accordance with one's Nature, and in Storytelling System games by following the needs of one's Virtue or Vice.