The Command Spells (令呪, Reiju?, also romanized as "Command Seals") are three claims of absolute obedience, the crystallization of a great magic, that a Master has over a Servant in the Holy Grail War system. Unable to normally be controlled by humans, they are burdened by the "absolute condition for materialization", the authority of the Command Spell carved into them at the moment of summoning. They are holy marks signifying a magi's status as a Master, a system that was created by Zouken Makiri after the failure of the First Holy Grail War. Only known to the Three Founding Families and Supervisor, their truest purpose is to allow the winner of the Grail to force the Servant to kill themselves so that the ritual to reach the Root with all seven Heroic Spirits can be completed.
Usage
Masters must take careful consideration into the usage of Command Spells because they can be indispensable as both an emergency measure and method of governing the Servant. Depending on the relationship, they are the only thing keeping a Servant bound to them, while others will stay by their Master even without them, and those like powerful Berserkers cannot be ordered without them. Some Servants will become more antagonistic towards their Master should they attempt to bind them, so they pay careful consideration before using them. It is normal that a Master has general control of their Servant even outside of the Command Spells due to them being the anchor that ties them to the world with their magical energy. With those who have the Independent Action skill and can act independently from the Master, the Command Spells may be the only possible way to order them.
Command Spells require no incantation unlike normal spells, and the Master only needs to put their mind to it and order the Servant. Imagining the shape of the Command Spell and giving the order as they release it is enough to activate it. The proximity does not matter, allowing for it to take effect even if the Servant is miles away or through a Bounded Field advanced enough to cut off all other communication. It can be performed unconsciously if the command is direct enough, but will not be used if they are not serious about the Command.[7] The command needs to be put into words, so removing the jaw before it is fully spoken enough to stop it. Cutting off the hand with the Command Spells just as the command is spoken is also able to keep it from coming into effect.
They are three absolute orders of unconditional obedience that can either restrain or reinforce the action of a Servant. While geas can control the actions of the recipient to an extent, they cannot take direct command of their life. Command Spells can force Servants to do anything possible for them, even committing suicide. The strength of the command depends on the Master, directness of the order, and the amount of energy it requires. Those that are broad and long lasting will weaken the power of the Command Spell. Though it will last for a long time, orders like "protect me through this" and "win this battle" will make the pain associated with the command weak enough for a Servant to disobey. Normally a command like "obey my every order completely" could not be done even with one hundred Command Spells, but a powerful enough Master can change the effect from "well, I'll respect Master's opinions slightly" to dropping them a rank if they disagree with the Master.
Commands with simple orders like "deliver the next blow with all your power" and "don't break that glass" are the most absolute of commands, and even the most powerful of Servants will find it hard to disobey. Those that both the Master and Servant agree upon are most powerful, allowing for them to go beyond the ability to enforce orders. Supporting and amplifying the Servant, miracles beyond their normal capabilities become possible. While most cannot use Spatial Transportation on their own, ordering "go", having enough energy, and having the Servant's consent allows the Command Spell to overturn the normal methods of magecraft to make it possible to reach into the unprecedented level of Magic. Even vague orders to win that are absolutely agreed upon by both parties can have a great effect in amplifying the Servant's energy so long as they are aspired towards victory. It can allow for a Noble Phantasm to exceed its normal maximum output and perform actions beyond its normal scope like distorting cause and effect to surely hit the target. In temporarily strengthening a Servant, it converts its magical energy into energy for the Servant, enough to fill even Saber's enormous circuit.
Depending on the order, it will be impossible for the Servant to even try to resist beyond a few scant seconds of great pain. When forced to act, the Servant will use all of their abilities without any regard for their will. Like a machine, they can only watch and lament as they are manipulated. Weaker orders can be resisted at the cost of pain and decreased abilities. Those that are too broad can be almost completely ignored and have little lasting effect. Depending on the order, it will stay in effect for the duration of the Holy Grail War. It cannot be overturned by the Servant, and only the cancellation of the contract will cause it to stop being in effect. The only way to stop a direct order from a Command Spell is through the usage of another Command Spell to overwrite it. Other types of orders can be removed without such a method, such as Kayneth rescinding his order for Lancer to fight Saber and Archer asking for approval from Rin to lift her command of not harming Shirou. If a Servant is fatally wounded, an order such as "heal right this instant" will result in the wound being temporarily sewed shut with a thread of magical energy, allowing the Servant to survive for a brief period; it does not, however, provide any actual medical treatment. If a Servant is ordered to protect another person and that person may potentially seek to harm their Master, the Servant cannot work with that person unless they confirm their intentions.
While Servants can attempt to resist orders and fight against them to a certain extent, the ability to completely go against them is to "shake the very foundation of the Servant System." As they are magecraft, the A-rank Magic Resistance of Saber and Rider of Black are great enough to repulse and withstand a single stroke of a Command Spell. Saber has shown that some commands can completely overwhelm her, while she can fight back against those she is vehemently against. Against that of Caster, she is shown to be constantly under the effect and would eventually succumb with time. Given that it takes most of their strength to resist, they feel as if they are being torn apart and do not have the strength to resist a second stroke, immediately being crushed under the weight of both commands. It is possible for a Servant to lose all sense of themselves and forget the command given to them. Other means of resistance include:
Berserker is such a Servant that he could easily cancel the control of Command Spells of a normal Master, so he can only be controlled by Illyasviel von Einzbern's special Command Spells. Berserker of Red, the "hero of rebellion" who vehemently fights against such "shackles" and possesses an abnormal EX Mad Enhancement, will only be weighed down by a single Command Spell. He won't stop his advance or obey unless two are expended, and at the maximum level of Crying Warmonger where his energy goes beyond the binds of the Servant contract, even three would not be enough to stop him. Lancer of Black, after using Legend of Dracula and having Darnic Prestone Yggdmillennia's soul fused into his own, becomes a monster that can no longer be called a Servant. He cannot be bound by Command Spells in such a state, and due to Darnic's influence, could reject even a command from Ruler to kill himself. As Command Spells and Magic Circuits are different systems of magecraft, it is possible to exercise them without the ability to circulate magical energy. The can be used and forged into highly practical magical energy that has no alignments, and enough of them can act as expandable mock Magic Crests capable of rivaling houses that have built their Magic Crests for generations. With enough Command Spells, it becomes possible to harm even a Servant.
Transference
though they contain an enormous power and can be considered a kind of miracle, Command Spells are a form of exhaustible physical enchantment that can be transplanted or transferred through incantations. Depending on the willingness of the one losing the Command Spells, it can be done easily or forcibly with different methods. Sola-Ui Nuada-Re Sophia-Ri's method of spiritual healing can only extract them with consent from the owner. Kirei Kotomine can use Spiritual Healing with a brief moment of pain to take Command Spells willingly. Assassin of Black, admittedly not very good with transplant operations, can use her Surgical Procedure to transfer them in a process taking an hour. The Supervisor only needs to trace the marks on a Master's hand to transfer their Command Spells, but it is impossible to extract them by force with magecraft. They are protected by holy prayers, so only those who know the secret holy words may take them. Upon speaking the words, they are transferred one by one to the speaker.
As the Command Spells are integrated with the Magic Circuits, forcibly ripping off the Command Spells is roughly analogous to tearing out someone's nerves; therefore, if done poorly, the unfortunate victim can end up permanently crippled. Removing the limb and nerves containing the Command Spells allows for them to be taken and transferred at the person's leisure, but must be done before the original Master dies. No matter how superior of a magus, one cannot become a Master just by stealing a Command Spell because it is only something that can be done between Masters and Servants.
Usage
Masters must take careful consideration into the usage of Command Spells because they can be indispensable as both an emergency measure and method of governing the Servant. Depending on the relationship, they are the only thing keeping a Servant bound to them, while others will stay by their Master even without them, and those like powerful Berserkers cannot be ordered without them. Some Servants will become more antagonistic towards their Master should they attempt to bind them, so they pay careful consideration before using them. It is normal that a Master has general control of their Servant even outside of the Command Spells due to them being the anchor that ties them to the world with their magical energy. With those who have the Independent Action skill and can act independently from the Master, the Command Spells may be the only possible way to order them.
Command Spells require no incantation unlike normal spells, and the Master only needs to put their mind to it and order the Servant. Imagining the shape of the Command Spell and giving the order as they release it is enough to activate it. The proximity does not matter, allowing for it to take effect even if the Servant is miles away or through a Bounded Field advanced enough to cut off all other communication. It can be performed unconsciously if the command is direct enough, but will not be used if they are not serious about the Command.[7] The command needs to be put into words, so removing the jaw before it is fully spoken enough to stop it. Cutting off the hand with the Command Spells just as the command is spoken is also able to keep it from coming into effect.
They are three absolute orders of unconditional obedience that can either restrain or reinforce the action of a Servant. While geas can control the actions of the recipient to an extent, they cannot take direct command of their life. Command Spells can force Servants to do anything possible for them, even committing suicide. The strength of the command depends on the Master, directness of the order, and the amount of energy it requires. Those that are broad and long lasting will weaken the power of the Command Spell. Though it will last for a long time, orders like "protect me through this" and "win this battle" will make the pain associated with the command weak enough for a Servant to disobey. Normally a command like "obey my every order completely" could not be done even with one hundred Command Spells, but a powerful enough Master can change the effect from "well, I'll respect Master's opinions slightly" to dropping them a rank if they disagree with the Master.
Commands with simple orders like "deliver the next blow with all your power" and "don't break that glass" are the most absolute of commands, and even the most powerful of Servants will find it hard to disobey. Those that both the Master and Servant agree upon are most powerful, allowing for them to go beyond the ability to enforce orders. Supporting and amplifying the Servant, miracles beyond their normal capabilities become possible. While most cannot use Spatial Transportation on their own, ordering "go", having enough energy, and having the Servant's consent allows the Command Spell to overturn the normal methods of magecraft to make it possible to reach into the unprecedented level of Magic. Even vague orders to win that are absolutely agreed upon by both parties can have a great effect in amplifying the Servant's energy so long as they are aspired towards victory. It can allow for a Noble Phantasm to exceed its normal maximum output and perform actions beyond its normal scope like distorting cause and effect to surely hit the target. In temporarily strengthening a Servant, it converts its magical energy into energy for the Servant, enough to fill even Saber's enormous circuit.
Depending on the order, it will be impossible for the Servant to even try to resist beyond a few scant seconds of great pain. When forced to act, the Servant will use all of their abilities without any regard for their will. Like a machine, they can only watch and lament as they are manipulated. Weaker orders can be resisted at the cost of pain and decreased abilities. Those that are too broad can be almost completely ignored and have little lasting effect. Depending on the order, it will stay in effect for the duration of the Holy Grail War. It cannot be overturned by the Servant, and only the cancellation of the contract will cause it to stop being in effect. The only way to stop a direct order from a Command Spell is through the usage of another Command Spell to overwrite it. Other types of orders can be removed without such a method, such as Kayneth rescinding his order for Lancer to fight Saber and Archer asking for approval from Rin to lift her command of not harming Shirou. If a Servant is fatally wounded, an order such as "heal right this instant" will result in the wound being temporarily sewed shut with a thread of magical energy, allowing the Servant to survive for a brief period; it does not, however, provide any actual medical treatment. If a Servant is ordered to protect another person and that person may potentially seek to harm their Master, the Servant cannot work with that person unless they confirm their intentions.
While Servants can attempt to resist orders and fight against them to a certain extent, the ability to completely go against them is to "shake the very foundation of the Servant System." As they are magecraft, the A-rank Magic Resistance of Saber and Rider of Black are great enough to repulse and withstand a single stroke of a Command Spell. Saber has shown that some commands can completely overwhelm her, while she can fight back against those she is vehemently against. Against that of Caster, she is shown to be constantly under the effect and would eventually succumb with time. Given that it takes most of their strength to resist, they feel as if they are being torn apart and do not have the strength to resist a second stroke, immediately being crushed under the weight of both commands. It is possible for a Servant to lose all sense of themselves and forget the command given to them. Other means of resistance include:
Berserker is such a Servant that he could easily cancel the control of Command Spells of a normal Master, so he can only be controlled by Illyasviel von Einzbern's special Command Spells.
Berserker of Red, the "hero of rebellion" who vehemently fights against such "shackles" and possesses an abnormal EX Mad Enhancement, will only be weighed down by a single Command Spell. He won't stop his advance or obey unless two are expended, and at the maximum level of Crying Warmonger where his energy goes beyond the binds of the Servant contract, even three would not be enough to stop him.
Lancer of Black, after using Legend of Dracula and having Darnic Prestone Yggdmillennia's soul fused into his own, becomes a monster that can no longer be called a Servant. He cannot be bound by Command Spells in such a state, and due to Darnic's influence, could reject even a command from Ruler to kill himself.
As Command Spells and Magic Circuits are different systems of magecraft, it is possible to exercise them without the ability to circulate magical energy. The can be used and forged into highly practical magical energy that has no alignments, and enough of them can act as expandable mock Magic Crests capable of rivaling houses that have built their Magic Crests for generations. With enough Command Spells, it becomes possible to harm even a Servant.
Transference
though they contain an enormous power and can be considered a kind of miracle, Command Spells are a form of exhaustible physical enchantment that can be transplanted or transferred through incantations. Depending on the willingness of the one losing the Command Spells, it can be done easily or forcibly with different methods. Sola-Ui Nuada-Re Sophia-Ri's method of spiritual healing can only extract them with consent from the owner. Kirei Kotomine can use Spiritual Healing with a brief moment of pain to take Command Spells willingly. Assassin of Black, admittedly not very good with transplant operations, can use her Surgical Procedure to transfer them in a process taking an hour. The Supervisor only needs to trace the marks on a Master's hand to transfer their Command Spells, but it is impossible to extract them by force with magecraft. They are protected by holy prayers, so only those who know the secret holy words may take them. Upon speaking the words, they are transferred one by one to the speaker.
As the Command Spells are integrated with the Magic Circuits, forcibly ripping off the Command Spells is roughly analogous to tearing out someone's nerves; therefore, if done poorly, the unfortunate victim can end up permanently crippled. Removing the limb and nerves containing the Command Spells allows for them to be taken and transferred at the person's leisure, but must be done before the original Master dies. No matter how superior of a magus, one cannot become a Master just by stealing a Command Spell because it is only something that can be done between Masters and Servants.