Master

Master (マスター, Masutā^?) is a designation given to an individual, usually a magus, who has become one of the formal participants of the Holy Grail War by obtaining Command Spells and forming a contract with a Servant.

Characteristics

With advanced manipulation of the system, it is possible to accomplish feats like having two Masters for one Servant. Kayneth El-Melloi Archibald takes control of the Command Spells, while his wife, Sola-Ui Nuada-Re Sophia-Ri provides energy. Either one is capable of holding or accepting new Command Spells to control the Servant.

It is not possible for a person who is not a Master to steal Command Spells to become a Master, but a Master creating a Book of the False Attendant can provisionally transfer it so long as the person retains the book.

Under ordinary circumstances, a Master is always a spellcaster, usually a Magus with a Magic Circuit, who is selected by the Grail. It is possible for an ordinary person to become a Master, as in the case of Souichirou Kuzuki, as well as untrained individuals such as Ryuunosuke Uryuu, though this is rare.

A Master that is providing magical energy to a Servant will "leak" magical energy in a volume that is easily detectable to most spellcasters. The leakage is distinctive, allowing a Magus to determine that the Master has a contract with a Servant.

An active Master will also possess a Command Spell as a visible proof of their contract.

A Master is always a Master, whether he currently has a Servant or not, as long as he still has the Command Spell. A Master without a Servant can make a pact with an unclaimed Servant at will, though having too many Servants is hazardous to the health of a Master due to magical energy consumption. This also means that a Master can claim a new Servant regardless of the length of time since his last Servant.

Under the Fuyuki-related systems, it is possible for a Master to contract with as many Servants as they wish, but even excellent magi cannot materialize more than one Servant at once. The result would just be splitting their potential power by the number of Servants. Kirei Kotomine, Caster, Sakura Matou, and Shirou Kotomine avoid that obstacle by using alternate energy sources to provide magical energy for a number of Servants at once. Under the Moon Cell system, all Servants have a direct connection to the ID of their Masters, so the system inherently prohibits Masters from possessing more than one contract. Chaldea Security Organization's FATE system allows for hundreds of Servants to be materialized at once under the same Master by providing for their magical energy needs and augmenting the amount of magical energy they can hold. That said, due to the difficulty of coordinating the activities of multiple Servants and the risk of causing unnecessary strain on the Master only a handful of them are deployed at any given time; the remaining Servants remain on standby in Chaldea but can be called upon for aid whenever they are needed.

Magical Paths

In providing magical energy to their Servant, they are connected by Magical Paths to facilitate the energy. The Master has complete control over how much energy is granted, allowing them to have hold over the actions of the Servant except in cases where they possess Independent Action. They can limit the energy to keep the Servant at a level below themselves like Caster's original Master, and they can cut it off to force Servants into spiritual form. The Servants have some control over accepting the energy, allowing Rider to exclusively use his own energy to actualize his Noble Phantasm to keep from draining his Master to death due to his inferior ability as a magus. It is possible to redirect the paths to other magi, allowing for the burden on the main Master to be greatly reduced. If there is a problem in establishing the paths or if the Master is unable to provide energy due to being a normal human, the Servant will be limited to only their current stock of energy unless they establish outside means like draining from the leylines or eating human souls.

Masters and Servants share a deep mental connection, so it has been observed that both can see visions of each other's pasts in the form of dreams. It is a known phenomenon said to have widely occurred in the first three Fuyuki wars, the derivative wars of the Fate/Apocrypha world, and the Grand Orders, so those who know of it do not find the experience to be mysterious. While Servants do not need to sleep and do not normally have the capacity to dream even if they force themselves to do so for the purpose of saving energy, Servants can see the pasts of Masters as dreams as well. The viewers sometimes only realize the dreams' nature after waking and are sometimes conscious of themselves within the dreams, but are unable to reject them even if it means intruding on the mind of the other.

Goals

Traditionally, a Master is an individual who has formed a contract with a Ghost Liner type Familiar, for the purpose of acquiring the Holy Grail of Fuyuki City. There are no actual restrictions on how the contract is used, when it is made, or how long it lasts, but the Servant inevitably has goals of its own which complement those of the Master.

Creation

In order to become a Master, a person must successfully summon a Servant through the use of a specific Formal Craft ritual. Upon completion, the Master must formalize a contract with the Summoned Servant by acknowledging their respective roles. The process creates a link between the two, allowing the Master to support the Servant with their magical energy or an external source.

In every known case, with one exception, Masters only occur through the power of the Great Grail of Fuyuki City. The Grail both selects prospective Masters according to their need and provides the majority of the energy needed to manifest and maintain the Servant. It also provides the Command Spells which grant limited control of the Servant to the Master.

The one exception to the rule is the case of Illyasviel von Einzbern, who successfully summoned Berserker without the aid of the Grail through the techniques of the Einzbern family. Her Command Spells were physically inscribed on her body with an unknown power source. The Grail recognized her as a legitimate Master, despite the abnormality, as she had the aptitude to become the vessel of the Lesser Grail.

Card User

Card Users (カード使用者^?) are those participating in the Ainsworth Holy Grail Wars. Instead of summoning Servants as familiars, Card Users use Class Cards to imbue the power of Heroic Spirits directly into their bodies to fight each other.