The Power of Blood

""For the soul of every sort of flesh is its blood by the soul in it. Consequently I said to the sons of Israel: 'You must not eat the blood of any sort of flesh, because the soul of every sort of flesh is its blood. Anyone eating it will be cut off.'""

- God, Leviticus 17:14

""Blood is life, lackbrain. Why do you think we eat it? It's what keeps you going. Makes you warm. Makes you hard. Makes you other than dead.""

- Spike, Buffy the Vampire Slayer

Blood. Animals have it, humans have it, even aliens have it. There's just something about the red liquid that flows through our veins that makes it seem important. Probably something to do with that whole..."keeping us alive" thing it does so well. As such, in fiction, it tends to have one or more of these properties.


 * A) Blood is binding -- Any Magically Binding Contracts made in blood must be honored, on pain of death, even if the contract was only written in blood because you Couldn't Find a Pen. If you make a Blood Oath, and swear that "if you break your word, may the earth drink your blood!", and break your word anyway, you may find yourself six feet under.


 * B) Blood is symbolic -- Blood may be used as a stand-in, or weaker form of souls, life force, what have you. Alternatively, other things may be used to symbolize it. The latter applies to things like an android's oil being sprayed out like it's High-Pressure Blood.
 * For examples of the latter, see Alien Blood or Symbolic Blood.


 * AB) Blood is magical -- Any spells that require blood as a reagent will probably be either extremely powerful, Black Magic, or both. Since blood is basically Life Force, anything using it will work similarly to things Cast From HP. The blood of especially powerful or arcane creatures may even become gems.


 * O) Most importantly, Blood is disturbing -- There's just something about blood leaving the body that generally freaks people out, either from fear or disgust. For obvious reasons, it's directly associated with pain, injury and death. Horror and Slasher stories rely on this. A further division of this, often connected to A, B, or AB, are messages written in blood, which are used primarily to scare the bejeezus out of people, but may also have magical, symbolic, or binding properties. This is sometimes combined with Room Full of Crazy for the extra creepy. Properly used, blood can turn fear into Primal Fear - as per the shower scene in Psycho: the sight of Janet Leigh's hand trailing slowly down the shower curtain - scary. The blood (actually just chocolate syrup) smearing under her fingers - PSYCHO! Many movies overdo this, resulting in mere Squick - Silent Hill pours on the tension until your heart threatens to explode from your chest - scary. Then Pyramid Head shows up and tears the skin from a woman in a single tug - not that scary, just your basic Gorn.

Now, remember: Type AB Blood Power draws off of all the others, and all of them draw from Type O. Just be aware of the donor; may contain Bloody Hilarity.

Anime and Manga

 * It's explicitly said in Chrono Crusade that when Chrono made a contract with, that she had to give him some of her blood to complete it. It's implied (using vampire imagery) that this was also the case with his contract with Rosette.
 * How forget Escaflowne? the movie version took it Up to Eleven
 * Eureka Seven
 * In Naruto, to summon animals one must first sign a summoning contract. It requires that the user must sign it in his/her name in their own blood followed by a fingerprints stamps in blood as well.

Film

 * In the film Mongol, young Temudgin makes a blood oath with Jamukha, who saved his life. This makes Jamukha the brother to Temudgin, and in the end,
 * Being 'blood brothers' is part of many westerns
 * McClintock
 * Being deemed negro was an important plot point in Show Boat. By sharing a drop of blood, the hero was now deemed negro and could marry his sweetheart without violating the miscegenation laws.

Literature

 * Tortall Universe 'Trickster's Choice/Trickster's Queen'- an oath sworn in blood kills anyone who breaks it, with the blood boiling in their veins.
 * Marie Brennan's Doppelganger duology features a blood-oath as a plot point in both books. If the oath is broken, the magically-sealed scar will bleed the Hunter to death through one wrist. Unique in that the oath binds both parties to their word (presumably; the actual wording states that the contractor binds him/herself to grant the contractee three boons without conditions, so magical compulsion may or may not extend to the contractor). Also a slight crossover with Type AB, as blood is used not only to bind the contractee, but as an elemental focus for shaping the complicated spell, and while it represents Fire in the blood-oath spell, it is "one of the rare foci that can serve for more than one."

Tabletop Games

 * In both Vampire: The Masquerade and Vampire: The Requiem, Vampires is highly addictive to both vampires and mortals. The eponymous Blood Bond is formed when someone drinks three times from the same Vampire within a period of time, and forms such an intensely emotional and psychological bond in the drinker that it becomes difficult for them to willfully do anything which could cause even distress or disappointment in the host vampire.
 * Warhammer 40000: the Grey Knights keep a massive library containing the true names of daemons, each written in an Imperial servant's blood one syllable at a time per copyist to prevent the daemon from having power over the book it's kept in.

Theatre

 * Two words: Doctor Faustus.
 * Averted in Damn Yankees, where Applegate laughs at the idea of having Joe sign his name in blood to the contract.
 * Show Boat, as described above.

Web Comics

 * In Sluggy Freelance only Gwynn can use the Book of E-Ville to cast spells because her name has appeared on the inside cover written in blood. Right above instructions to, if lost, drop in any mailbox to return it to the rightful owner.
 * In Sinfest, Satan wants the forms and waiver filled out in blood, of course.

Web Original

 * Whateley Universe example: Carmilla and Fey made a blood pact that was so powerful it gave them some of the other's traits. Carmilla now has Fey's body (including Pointy Ears) and hair, and Fey got some of Carmilla's mental capacity.

Anime and Manga

 * In Fullmetal Alchemist, Ed and Al use drops of their blood to stand in for "information of the soul" when trying to bring back their mother from the dead using alchemy.
 * Philosopher's Stones also comes in various forms. Solid, liquid, they're all blood red.

Tabletop Games

 * In an extension to the Vampire: The Masquerade example above, the Kuei-Jin, the Asian equivalent to Vampires, live on life-force. The weaker ones drink blood simply because that's the easiest way to get at somebody's life-force. The stronger ones can straight-up eat your soul.

Literature

 * In the Sword of Shadows series, blood is sacred to the Sull, who bleed themselves as a form of offering to their gods. Obviously, most Sull become very skilled at letting blood with minimum pain and without hitting anything important.

Anime and Manga

 * In Tower of God, King Zahard transfers power to Zahard's princesses, his adopted daughters, by his blood.
 * In Princess Tutu, Drosselmeyer wrote a story in his own blood.
 * Also, the Raven is so evil that his blood can turn people evil when they ingest it, bathe in it, or have it otherwise go into their body.
 * The jousei manga It's Not Like That, Darling uses a more passive form of this trope (a combination of Type B and Type AB). The main character gets a blood transfusion after an accident in the backstory. Later, the donor dies in another, unrelated accident and our heroine finds herself having the strangest thoughts... A tolerably good romantic comedy, as such things go.
 * In Clive Barker's Clive Barker's Jericho (by Clive Barker), the character of Wilhelmina "Billie" Church is a blood mage, whose spells can bind enemies and set them on fire. Her blood magic and abilities are also very important to certain aspects of the story.
 * In Mahou Sensei Negima, Evangeline, who was de-powered into being stuck on the school's campus by Nagi the Thousand Master says an ample (probably fatal) drinking of blood from him or one of his relations will somehow lift the curse.
 * It's stated (at least in the English translation) that an alternate method of executing a Pactio is "open veins, swap blood", but that's not as Fan Service-y as kissing, so it's never actually been done that way.
 * Even later, Negi learns a spell that requires him to bleed before he can use it, although that may be only in it's incomplete form. He uses the full version later and doesn't bother with the blood.
 * In Black Cat, Sheldon's Tao is manipulating blood.
 * In Fullmetal Alchemist, Ed uses his blood to draw the alchemical seal which binds Al's soul to the suit of armor. Apparently, being produced in a living body and rich in iron makes blood a good intermediary between souls and steel.
 * Hellsing, where it has slight crossover with Type B when referred to as "the currency of the soul." This just seems to be a poetic turn of phrase due to the fact that Alucard absorbs his meals' memories when he consumes their blood. Later, however, it's revealed that.
 * In Rumiko Takahashi's Mermaid Saga, mermaid flesh can, if you're (un)lucky enough to survive eating it without becoming a Lost Soul, turn you immortal. But in the "Mermaid Forest" story, all that Sawa has is a flask of mermaid blood to heal her sister's illness. It made Towa immortal, but deformed her arm like a Lost Soul's, and now she regularly replaces it with arms cut from the fresh corpses of young women.
 * Referenced in Hell Teacher Nube. Here, flesh from the (still living) mermaid Hayame has a 100% success rate, and her blood can instantly heal any injury no matter how grave, without conferring immortality. It does have the side effect of making the recipient into a moron for a short while, seeing as it comes from Hayame, after all.
 * One of the Contractors in Darker Than Black, Wei, is able to teleport away anything that is covered in his blood. This power is frequently used to create gaping holes in the torsos of his enemies. Naturally, the only way he can use this power is by carrying a knife and cutting his own wrists to toss blood on opponents. In case you couldn't tell, he's a bad guy.

Comic Books
"Batman: A spell written in blood. For a mage like Zatanna, no enchantment is more powerful."
 * In A Game Of You, menstrual blood is used to power a spell to send the characters to the land of the dead and come back alive . In The Time Of Your Life, the same spell is powered from blood from Foxglove's hand.
 * Another parody happens in Lenore the Cute Little Dead Girl, when she pricks her finger and spills a drop of blood on a doll. It turns out to be a vampire that was cursed to be an inanimate plaything, and her blood broke the curse. Unfortunately, he realizes he's still in a doll's body because the curse didn't break properly; she'd been embalmed.
 * Runaways: "When blood is shed, let the Staff of One emerge."
 * In Detective Comics #833 Zatanna is shot in the throat by the Joker and dunked into a tank filling with water, effectively keeping her from reciting her incantations backwards. When Batman escapes his own deathtrap to free her in #835, he finds her throat completely healed. Upon inspection, Bats discovered she'd used her own blood to write "HEAL ME" backwards on the inside of the tank's lid.

Film

 * The Golden Voyage of Sinbad. The wizard Prince Koura uses his own blood to create a homunculus.
 * Ryuhei Kitamura's Versus revolves around the "Blood of Resurrection," which the villain plans to use in the Forest of Resurrection to open some kind of a dark door and get "The Power." Zombies and reincarnated samurai are involved.
 * The blood of those who took the coins from the Chest of Cortez is required to lift the curse inPirates of the Caribbean: The Curse of the Black Pearl.

Literature

 * Melisandre of A Song of Ice and Fire uses the blood of a king in a ritual to . Possibly. The maegi Mirri Maz Duur also uses blood magic to   and the favor is returned by Daenerys when she
 * This was also part of the Targaryens' reasoning for their rampant incest.
 * Mercedes Lackey loves this concept, and blood mages are frequently villains in her books. Combines with Type O, since the shedding of blood is incidental -- the suffering and trauma of the victim is the real source of power.
 * There are also good people who use blood magic--they only use their own blood. Most notably, the Shin'a'in, whose patron goddess will sometimes require someone (usually a shaman) to sacrifice themselves to prove the people's need.
 * In Stardust, the witches use the hearts of living stars to prolong their youth as a form of blood magic.
 * In Harry Potter, Voldemort uses . In addition to reviving himself, it gives Voldemort the power to touch Harry, because the all-sacrificing love that Lily imparted to her son resided in Harry's blood. This later  didn't stop a rebounding Killing Curse later on.
 * Also, in Harry Potter, a small blood sacrifice is needed
 * And then there's unicorn blood. It will, according to Firenze, "keep you alive, even if you are at the brink of death, but at a terrible price. You have slain something pure and defenseless to save yourself, so you will have but a half-life, a cursed life, from the moment the blood touches your lips."
 * Discworld parodies this with the Rite of Ashk'Ente, which summons Death - it's implied that this is supposed to require a human sacrifice, but magical refinements mean that it's now possible with only "4 cubic centimetres of mouse blood".
 * In Carpe Jugulum, Granny Weatherwax uses this kind of blood magic against vampires by


 * In the Book of Amber series, the mystic Pattern that created the universe was drawn in the blood of its creator. The discovery that the blood of his descendants could erase it drives part of the plot.
 * In the Codex Alera series, the Alerans have magical creatures living inside them that give them elemental magic powers. The werewolf-like Canim don't have inherent magic like that.
 * To elaborate, we only see three spells cast by Canim ritualists. One creates clouds of acidic mist, another summons tentacled horrors from midair which are also acidic or at least venomous, and a third calls down lightning on chosen targets. All of these require the spilling of blood. However, it is stated that ritualists are also their peoples' priests and doctors, so presumably they have more benign spells that we don't see because we only see them during battles. In addition, some Canim use the blood of their enemies to fuel spells and sometimes kill civilians specifically for their blood, but more noble ritualists only use blood from volunteers or their own.
 * On the 'Night of Red Stars', the Canim ritualists cast a spell that puts acid mist clouds full of weird seemingly extradimensional tentacle monsters over a good part of the continent, preventing the Alerans from flying (since they get eaten/dissolved if they try to go through the clouds). But this huge spell is said to cost millions of Canim lives.
 * The Mosquito-kinden of Shadows of the Apt have a serious thing about blood, and huge quantities turn up in some prophecies.
 * Also from Sword of Shadows, it's possible for weaker sorcerers to enhance their powers by draining blood from a properly bound stronger sorcerer. Penthero Iss demonstrates both the binding and the bloodletting in Nightmare Fuel detail.
 * In the Old Kingdom trilogy by Garth Nix, the power of the Charter that gives the King, Abhorsen, and Clayr their unique abilities is found In the Blood - as in, both genetically and literally. Charter Stones, which keep the magical Old Kingdom sustained, can be broken if a Charter Mage's blood is spilled on them (in death), and the Great Stones can only be broken by the blood of one of the Charter bloodlines (see above.) Finally, in Abhorsen,
 * In one of Tamora Pierce's Circle of Magic books, Niko cuts his palm so that he can use his own blood to fuel a past-viewing spell, saying that mages will often use blood to make a spell more powerful. He then says some use their own, others use the blood of others - willing or not - and sternly warns the student listening to him not to use others.
 * Some cross-over with Type A in the Chronicles of the Kencyrath with blood-binders- Kencyr who have the inherent magical ability of creating a telepathic link with anyone who's exposed to their blood, a link that is so powerful that can endure past death. Darkling Changers have a related ability of being able to take the form of anyone whose blood they've sampled. If a Changer tries to feed on a blood-binder, and the blood-binder's magic is stronger, then the Changer will be wracked by intense pain, the only known release form which is death.

Live Action TV

 * Seeing as it provided the title quote it's not surprising that Buffy the Vampire Slayer has a few examples of this. The blood of a slayer apparently has mystical qualities, allowing Angel to survive Faith's poison, and granting the Master the strength to escape his prison in the first season. Dawn's blood was used by Glory to open the interdimensional portal.
 * Angel also used this quite extensively. The Beast dripped blood onto the artifacts it had gathered as the final part of its ritual to blot out the sun. The blood of a virgin was used to expedite the birth of Jasmine. Lorne's blood was used in another ritual calling for the blood of a demon. And of course Hamilton's blood turned out to be full of the power of the Senior Partners. There are probably a lot more. Any show with vampires and magic is likely to feature a lot of this trope.
 * In the Doctor Who episode "The Christmas Invasion", the Sycorax use samples of A Positive that they took out of a satellite to control everyone in the world of that blood type.

Tabletop Games

 * In the Shadowrun supplement Aztlan, mages can use Blood Magic: spilling a human's blood to enhance spellcasting and summon Blood Spirits. Extremely evil, restricted to Non Player Characters.
 * Dungeons and Dragons: One of the material components for the Cacodemon spell (which summoned a powerful demon) was a bowl of mammal blood, preferably human.
 * In-character folklore (well, one version of it) of the default D&D pantheon holds that elves and orcs were born from the blood of their respective creator-deities, Corellon and Gruumsh, which got spattered across multiple worlds when their deities were fighting a death-duel (both survived, however).
 * Common in the Ravenloft setting, both as a power-source for certain kinds of evil magic and as a means for vampires to bequeath temporary vigor and prolonged life to their mortal minions.
 * Exalted uses this trope in several places. Lunar Exalted gain their myriad of forms to pick from by hunting the creatures they seek and drinking their heart's blood; Abyssal Exalts can recharge their power by drinking blood; and several sorcerous (and all necromantic) rituals also require the sacrifice of blood in the process of casting. Sometimes from the caster him/herself.
 * As mentioned above, both Vampire games take full advantage of this subtrope. Once blood enters a vampire's body, it becomes something more than blood (often referred to by vampires as "Vitae").
 * In Legend of the Five Rings, "Bloodspeakers" practice a very evil type of magic, powered by blood that is usually (though not always) unwillingly donated by others, who typically don't survive the experience.
 * In Rifts and the Palladium universe, blood sacrifices are common for most kinds of magic because P.P.E. doubles at the time of death. But the actual representatives of this trope are Blood Shamans, who cast grisly spells from their own blood with a bit of Casting from HP.

Video Games

 * In the Dominions series, spells from most schools of magic are cast using "gems" which are basically elemental forces (fire, water, etc...) concentrated into portable form, and the casting prices of spells are listed in these gems. Instead of gems, however, one school of magic lists spell prices in blood. These prices are listed in increments of one blood slave, each of which must be drained completely empty, with high-level spell costs running into the hundreds.
 * Dragon Age: Origins has the Blood Mage class type, which uses Cast From Hit Points types of magic. A Tevinter Imperium blood mage even uses his own henchmen as sacrifices, usually by making them explode with the words "A blood sacrifice! For power!"
 * "Reavers", a particularly dangerous type of warrior that become stronger through suffering and exhibit certain magical powers, are created by drinking the blood of dragons. There are entire cults that spring up around high dragons for this reason.
 * Grey Wardens themselves are created by drinking a special cocktail of darkspawn blood and lyrium, which makes them immune to the darkspawn taint . The Warden's Keep DLC also confirms that Grey Wardens can gain other abilities through their tainted blood.
 * In World of Warcraft death knights have power over blood. Those that specialize in it can apparently suck blood they've lost back inside them through Death Strike (or possibly drain it from their enemies into themselves, how it's supposed to work isn't entirely clear), create a "blood shield", boil the blood of the enemies, and create bloodworms to attack their enemies. Which burst from gorging themselves, healing nearby allies through a mechanism that appears to be showering them in other people's blood. All in all it's pretty Squicky.
 * This is part of the plot to Zelda II the Adventure of Link. Link killed Ganon in the original game, but several of his minions are still running amok in Hyrule. While he goes on the eponymous adventure to return six crystals to six palaces, he has to be careful; the minions want to kill him so they can scatter his blood on Ganon's ashes and return him to life.
 * The monstrous Zulwarn ATAC in Vanguard Bandits needs Blood in order to run.
 * In Okamiden, the Big Bad Akuro must bathe his vessel in blood to become perfect. Or, maybe he has to bathe himself. The game can't agree with itself on this point.

Web Comics

 * Subverted in Sluggy Freelance. Torg finds out that his talking sword Chaz only has its mystical abilities to speak and kill damn near anything if it has fed on the blood of the innocent first, and so assumes it's an evil sword. Chaz clarifies that it is simply a weapon, and whether it does good or bad things is entirely up to the person using it.

Web Original

 * In the Breeniverse series Lonelygirl15 and Kate Modern, infusions of Trait Positive blood can extend the human lifespan considerably. In LG 15 The Resistance, blood grants total immortality.
 * Fey of the Whateley Universe used the blood of Hekate to throw a major Sidhe curse on her: a three-fold return of all the evil Hekate had done, which (given just what we've seen) will be horrific.

Western Animation

 * Two words: Blood Bending. Ya know, for kids!

Anime and Manga

 * In Death Note, Villain Protagonist Light Yagami kills people by writing their names in pages of a supernatural notebook. For emergencies, he keeps a needle and scrap of Death Note paper in a secret compartment in his watch, which means that even in tense situations where he's under surveillance, he can murder people by discreetly writing their names in his own blood.

Comic Books
"Carnage: My blood wants to kill you!"
 * Spider-Man villain Carnage has an alien symbiote mixed into his bloodstream that allows him to shape his blood and use it as a weapon. This is sometimes played for a more horrific effect, particularly in Warren Ellis and Kyle Hotz's Body Horror laden graphic novel "Mindbomb"

Literature

 * Dracula.
 * Dolores Umbridge and her blood quill uses this, which clashes horribly with her otherwise Kawaiiko persona.
 * In Robert E. Howard's Conan the Barbarian story "Shadows in Zamboula" Baal-pteor offers Human Sacrifice with a Neck Snap, to save blood for the god.

Tabletop Games

 * In Graham McNeill's Warhammer 40000 Horus Heresy novel Fulgrim, the influence of the Laer temple causes Serena to add blood to her paint in hopes of capturing the vivid colors she imagines.
 * For that matter, one could count anyone who worships Khorne, the GOD of Blood.

Videogames

 * In the climax of Ico, we see the only blood in the game when . The sudden physical sign of violence after a game full of whacking nothing but intangible Smokemen is like a punch to the gut.

Web Comics
"Hanna: It must be because I use magic, it taints my blood, but ANYWAYS."
 * In Hanna Is Not a Boy's Name, Hanna's blood is apparently particularly disgusting, at least according to a vampire. He attributes this to his use of magic (before quickly changing the subject).


 * In Roza, her blood is magical. It glows.