Magic Prerequisite

These are the external factors needed to make a spell or ritual work. They fall under five main categories.

• The right time—when the moon is full, the summer solstice, an eclipse.
• The right place—somewhere mystically significant, such as Stonehenge or a place where two or more Ley Lines intersect.
• The right target—spells that only work on werewolves, or people wearing red.
• The right caster—spells that can only be cast by someone genuinely happy, or on the brink of death.
• The right condition of negation—spells that only work if there is a way to undo them.

They range from difficult to completely impossible for the caster to control. Persuading the target to wear red is fairly easy; making the sun set on command is beyond most wizards' powers.

Spells that only work at the right time serve to control the pace of a plot. If the Big Bad can only cast the ultimate spell of world domination on one specific night, that both gives the heroes a deadline and explains why the Big Bad didn't conquer the world ages ago. Spells that only work in the right place lead to battles for control of the key sites.

Inherent gifts are another common form of prerequisite; the spells only work for people born with the right talent.

See also Spell Construction, Power Source and Insert Payment to Use.

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Examples:

Anime and Manga

• The Contractors from Darker than Black, who are required to perform Remunerations whenever they use their powers, lest they suffer from Power Incontinence. These Remunerations range from smoking to eating boiled eggs to writing poetry to breaking a finger to drinking the blood of children, and a Contractor doesn't exactly get much choice in which one comes with their powers.
• A number of spells in Negima! Magister Negi Magi require that the magic of The World Tree be active in order to work, such as the spell the the festival arc's Big Bad attempts to use to break The Masquerade.
• In Yu-Gi-Oh!, Yami's power can only be activated through games. If his opponent loses the Shadow Game, he is free to dole out magical punishment.

Films — Animation

• In Turning Red, the red moon ritual only works during a lunar eclipse and if the person undergoing the ritual is within a chalk circle.

Film — Live-Action

• The Mask: The titular Mask of Power only works at night, apparently because Loki was a night god. Oddly enough,the cartoon features no such limitation.

Literature

• In Harry Potter, the brewing of Polyjuice Potion involved particular parts of a lunar cycle. Indeed, since Astronomy is a basic class celestial phases are probably involved in many kinds of magic; we just aren't given the tedious details.
  • Also, it's stated that a certain mindset is needed for certain spells, particularly hatred for the Cruciatus and Killing Curses.
  • And the Patronus charm, where the caster must be thinking of the happiest thought they can muster, which, given the circumstances of using the charm (being attacked by an Emotion Eater), is no easy task.
  • Magic in general can only be done by wizards. Give a muggle a wand and instruct them on how to cast a spell and they'll fail.
• In The Magicians, the effectiveness of spells vary depending on numerous factors (phase of the moon, the weather, etc) that students at Brakebills have to memorise. The fourth year at Brakebills South is dedicated to ensuring that the graduating students can act on these factors without even thinking about it.
  • Also, magic has to be practiced with a relaxed and stable mind, otherwise a particularly spectacular Magic Misfire will occur.
• The Dresden Files: In Blood Rites Murphy asks Harry why he just doesn't do the "pocket full of sunshine" trick on the Red Court vamps. He states it turns out you have to be genuinely happy to make the spell work.
  • More generally, no act of magic can be performed if the caster doesn't believe that it is an appropriate course of action. So if you don't believe that setting someone's face on fire is a good idea, you won't be able to do that (on purpose).
• Jonathan Strange & Mr. Norrell: Many spells only work while the "King's Roads" are active.
• This is the main limitation of magic in Rick Cook's Wiz Biz series. The more powerful the spell is, the more prerequisite it has and the more likely it is to fail or do something completely different if the prerequisites are not filled.
• The 'negation' angle comes up in the Discworld novel Sourcery. A wizard seeks to escape Death by sealing his soul inside his wizard's staff. Death tells him no deal, unless there's a condition that causes his soul to be released (because nothing escapes Death.) The wizard offers to let his soul be freed if his son willingly tosses aside his staff. Death accepts.
  • Well, his first suggestion was "when hell freezes over", but Death shut him down.
• Subverted in The Elenium. Sephrenia makes a huge deal about how magic spells must be cast in Styric, not Elene, but later it is revealed that this is because the spells are actually prayers directed at each Knightly Order's patron deity. Sparhawk speaks Elene to Aphrael on several instances when requesting magic be done, and she complies with no issues. Likewise, the Bhelliom is shown responding to Elene, Styric, Tamul, and even Troll.
• In Athyra, as Vlad decides to teach someone some of the basics of witchcraft, he mentions 'Places of Power'; practicing magic tends to be easier (particularly if it was created by someone performing magic there).

Live Action TV

• This is the only thing that keeps the universe of Buffy the Vampire Slayer from ending, since all the BigBads that want to destroy the world have to wait their turn and go to Sunnydale, where the Hellmouth resides, and where they have to face the Slayer.

Tabletop Games

• The cantrips of Changeling: The Dreaming had bunks, little obligations to the Dreaming that would make using a certain ability easier. Want to fly? Burn an eagle's feather, or tap your foot three times. Want to talk to rocks? Paint a little sigil on them. The more complex the bunk, the more likely the cantrip is to succeed.
• Chronicles of Darkness:
  • Changeling: The Lost: Each Contract has a specific Catch. By performing the Catch, the changeling avoids spending Glamour to activate the Contract. These Contracts range in applicability from "You must be fighting multiple foes, bare-handed, by yourself" to "You must use this power within five minutes of noon" to "Your target must be wearing or touching gold."
  • In Mage: The Awakening: Summoning Rituals impose extra conditions, unlike conventional spells:
    • Supernal entities can only be summoned by a mage whose Path matches the entity's home realm, and impose some kind of trial as part of the summoning. For example, to summon a spectre from Stygia, a Necromancer might have to prepare gifts that remind it of what it means to be alive.
    • Abyssal entities can only be summoned at a location tainted by evil and harm that match the spirit's area of influence, using similarly corrupt implements. A lesser Familiar only comes for someone who destroys a Spell Book with a piece from a fallen tower, whereas the Darkness that Thirsts requires a lightless place where atrocious human suffering has been concealed.
  • Immortals: Under the rules of Equivalent Exchange, Blood Bather rituals can be designed with more stringent conditions for greater benefits. A ritual that requires multiple Targeted Human Sacrifices, a full Cult ceremony, a marble tub, precious unguents, and the night of the winter solstice generates more metaphysical oomph than a quick dousing of animal blood.
• Dungeons & Dragons: Several cursed (or in this case unreliable) items have prerequisites that would render then practically useless, others just need to be used in the dark or by a certain gender.
• There are a number of spells in Magic: The Gathering that can only target creatures of a certain color; more commonly, creatures will have "protection from [color]," preventing them from being harmed by creatures or spells of that color. Finally, there are some spells that can target anything-but-color; this is mostly Black being unable to destroy other Black creatures, possibly symbolizing how Black can be its own worst enemy.
• Warhammer Fantasy Roleplay: Ritual Magic can surpass the limits of normal spellcasting but has more stringent prerequisites, ingredients, and consequences for failure. Vampires can only be resurrected on Unholy Ground; the Neiglish Rot can only be inflicted by a spellcaster who has survived it; a Sterility Plague can only target a bloodline with no currently pregnant members; and so on.

Video Games

• Warcraft III has several spells with targeting restrictions.
  • Most magic buffs and debuffs don't apply to mechanical units. Except, for some reason, Inner Fire, which increases armor and damage, and thus is often seen on the already hard-to-kill Siege Engines.
  • The Tauren Spirit Walker has the Ancestral Spirit spell which brings back a dead Tauren from the dead. Naturally, this only works on units classified as "Tauren", leading to major Gameplay and Story Segregation in Rexxar's campaign where centaurs (who are something of an Evil Counterpart to the tauren) were classified as such as one of their spellcasters had the same spell.
  • In-Universe with the revival of Kel'thuzad in the pool of mystic energy called the Sunwell (requiring the destruction of the high elf kingdom to reach it) and the summoning of Archimonde at Dalaran, requiring the use of a magical artifact and Kel'thuzad channeling magic for half an hour.

Western Animation

• Avatar: The Last Airbender:
  • Bloodbending requires a power boost from the full moon (unless you have the proper genes to bloodbend whenever you want). Explained by the moon being the power source for waterbenders, of which bloodbending is a complicated form.
  • On a variant, there is ten-fold amplification of firebending that allows for grand conquest only happens once every hundred years - Sozin's Comet. Whether conditions exist that would amplify air or earthbending (and why a comet would amplify fire and not earth or water) is open to speculation.
  • On a similar note, the various forms of Bending and the way they affect their respective cultures tend to breed different ways of looking at the world; in order to master any given form of Bending, Aang has to learn to think like its practitioners. Earth gives him particular trouble because the forceful, head-on approach of the Earthbenders is the polar opposite of the Zen, understand-all-angles approach he was raised with as an Airbender.
  • In a similar vein, Korra in the sequel has already mastered three of the four elements but has a mental block when it comes to Air because she is a Hot-Blooded person who likes to face challenges head-on. She also cannot tap into the Avatar state because of her lack of spirituality.
  • As the bending disciplines are stronger at certain times, so is there an off switch. Where there is a solar eclipse, firebenders lose their powers. The other elements' weaknesses are not known. (Yes, you'd think waterbending's a no-go during the new moon, but that's never stated outside the realm of fanfic).
  • Metalbending is apparently less bending the metal itself and more the impurities in the metal (e.g. if you interpret steel as iron and charcoal). Platinum, for whatever reason, is immune to this.
• In Gargoyles, magic works easier if there is a defeat condition built into it (Gargoyles were mystically turned to stone until the castle rose above the clouds, humans would continue to turn to stone at night until the sky burned with fire, etc). The conditions tend to be hard, but not impossible, tasks. Magic requiring it is the justification for the Curse Escape Clause trope being in effect when no Big Bad would ever create such a condition. The third race, being magically powerful by nature, rarely bother with such conditions.

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