Powered by a Forsaken Child



"Dr. Orpheus: It's powered by a FORSAKEN CHILD!?

Dr. Venture: Might be, kind of--I mean, I didn't use the whole thing!"

- The Venture Brothers, "Eenie, Meenie, Minie... Magic"

A piece of Applied Phlebotinum that doesn't work unless you pay a really ghastly price... or have someone else pay that price for you.

Can have The Dark Side effect, as in being willing to pay the price can make you more evil. May be the result of a Deal With The (Super-Powerful Alien) Devil. See also Black Magic and Utopia Justifies the Means.

May be a form of Aesoptinum. May use Human Resources or a Captured Super Entity as the Power Source. If done on a wide enough scale, it becomes Industrialized Evil.

Compare Artifact of Doom and May Contain Evil. Contrast Psycho Serum, for which the users themselves generally pay the price. See also Human Sacrifice and Horror Hunger. This is a type of Living Battery.

Anime & Manga

 * Subverted in Inuyasha, when Inuyasha obtains the red Tetsusaiga, an ability supposedly obtained by killing the guardian of the demon-bat caves. The guardian turns out to be a small half-demon child, Shiori, being forced to put a barrier around the caves. Inuyasha has to save her but won't kill her, at which she willingly gives him the ability by having him break open the crystal ball that created the barrier.
 * Magical Girl Lyrical Nanoha Strikers has the Saint's Cradle, a massively overpowered Cool Starship that can only power-up when commanded by a direct descendant of the Saint Kings of Ancient Belka. The problem? The last Saint King died over a hundred years ago without any heirs, so their bloodline is effectively extinct. So what is a Mad Scientist to do? Why, The problem with that?.
 * Puella Magi Madoka Magica:.
 * In Mahou Sensei Negima, as a child, was   used to power the magic-cancelling defense system of Ostia while bound in chains. Later she was also used to power the magic-cancelling spell that would have destroyed the whole Magic World. Thanks to everyone's joint effort at containment, only the whole of Ostia was destroyed. The resulting mental trauma from being used as the power source to destroy a whole country was probably one of the reasons Nagi and party decided to.
 * This is subverted in the case of Negi himself. Magia Erebea is literally powered by the body and soul of a forsaken child. The subversion lies in the fact that the child in question is also the (voluntary) user of the technique.
 * In Reborn, the first generation of the Gola Mosca were powered by Dying Will Flames.
 * As shown when Tsuna rips the Gola Mosca attacking Hibari and his friends apart and discovers a person inside of it. The situation is made worse for Tsuna since it was his grandfather', the 9th head of the Vongola family inside of it.
 * In Noein, the only thing protecting La'cryma from the encroachment of Shangri-la is a quantum computer powered by the humans embedded within it.
 * In Vision of Escaflowne Abridged, Emperor Donkirk became ruler of Zaibach by inventing a machine like this, one that turns blood into oil. As he put it "Cutting out the middle man"
 * "The Record of a Fallen Vampire" - the Black Swan parasite inhabits teenage girls to kill the Strauss. If they can't, they are themselves killed by the Black Swan, usually in about 5 years. Also,
 * In the original Blue Drop manga, the Arume use their own children as bomb disposal units. They also use synthetic ones, but the "sacrifice" of the Arume children is more "beautiful" in the Arume's way of thinking--even though the synthetic children are full-blown sentient beings in their own right.
 * Most of Fullmetal Alchemist revolves around figuring out what makes the Human Resources work best, since live human beings are ingredients to creating certain powerful artifacts. Later in Fullmetal Alchemist (2003 anime only), it's revealed that.
 * And in the manga/second anime, it is stated at some point that the Amestrian Alchemy but the Xingese Purification Arts and Xerxes Alchemy are clean. As the series progresses it is revealed that Amestrian Alchemy really does derive from the Earth's energies as originally taught,   More to the point,.
 * Galaxy Express 999 had the upper class using android bodies, powered by tiny energy cells that were made by harvesting humans.
 * In the Ghost in The Shell franchise, it is possible to produce hyper-real androids with all the neurological affectations of a living human via electronic "Ghost Dubbing". This process drains and kills the original after only a few copies are made, and in the Ghost In The Shell universe, it is a serious crime punishable by life in prison or getting your brain wiped; plotlines concerning the process appeared in Ghost In The Shell: Innocence, a few Stand Alone Complex episodes, and the original manga.
 * In Innocent Venus,  provide the neural systems in the mechas so that they are psychically compatible with the pilots. The memories of the trauma inflicted on them remain in the mechas, making it dangerous for pilots to stay psychically linked to their mechas for too long... Unless they're Complete Monsters.
 * In Kurau Phantom Memory, human beings are deliberately afflicted with Rynax energy in an attempt to turn them into superweapons. Since Rynax energy consists of sentient beings, this procedure almost always causes a lot of misery for all involved test subjects.
 * In Mai-HiME, the summon monsters controlled by the HiME tied to the life force of their "most important person" (a family member, boyfriend/girlfriend, etc.). If that monster is destroyed in combat, the person dies with it and fades into the ether, also robbing the HiME of her abilities.
 * Similarly, in Mai-Otome, the Otome usually can only use their robes after linking themselves to the life of a master.
 * Also in Mai-Otome,  is the Predecessor of the Valkyries.
 * One episode of the Miniseries MAPS featured an orbital laser that was powered by the psychic energy released by hundreds of small animals being brutally killed en masse.
 * The titular robots from Neon Genesis Evangelion are made from the cybernetically modified cloned flesh of the very aliens they're used to fight and.
 * And they're piloted by forsaken children, themselves. Incuding
 * Meta-example: Several of the crude images flashed up in End of Evangelion were drawn by abused children. Evangelion is itself powered by a forsaken child. It's that kind of show.
 * In Naruto, members of the Uchiha clan can only get the Mangekyo Sharingan by killing their best friend. The Anime has not revealed how Kakashi got his (which looks quite different), but the Manga reveals that
 * The manga has just revealed that
 * Akatsuki member Kakuzu
 * Fellow Akatsuki member Sasori
 * Jugo . However, he's a nice enough guy that.
 * Impure World Resurrection resurrects one dead person as an undying slave of the technique's user, at the cost of a live person used as a medium.
 * Soukou no Strain has the evil Deague searching for "samples", i.e. the mysterious alien Emilys. What they are samples of is.
 * Serial Experiments Lain features a scientist who tried to tap the psychic energy of hundreds of children, apparently draining them and leaving them in a deep coma.
 * There seemed to be a some sort of explosion caused by an overflow of psychic energy, dissolving the children's bodies, trapping them forever in the Wired. The scientist comments how no matter what he does, bringing them back to real world is impossible.
 * In Vandread, the enemy's planet harvest organs to support themselves on a planet so polluted that they had to convert the entire surface into a giant machine. The enemy has gone as far as to manipulate the cultures of human colonies to cater to the harvest.
 * The bloody war between men and women in the protagonists' home system exists only to prime sexual dimorphism for the reaping.
 * A planet of telepaths have had a strong oral tradition until their vocal cords were stolen. They developed their ability to compensate.
 * In Witchblade the I-Weapons are corpses that had a cloneblade stuck on them.
 * Orbo, the fluid in Witch Hunter Robin that nullifies witchcraft, is later discovered
 * There was also a witch whose power allowed him to sacrifice people to heal others. However, he only killed crooks, and eventually himself.
 * The Millennium Items in Yu-Gi-Oh are revealed to be created with the souls of 99 slaughtered victims.
 * In the original Japanese version,
 * Also, the Duel Monsters used in the show are actually the souls of at least several citizens and soldiers from Ancient Egypt during Pharaoh Atem's rule, if not from billions of people in the anime's past.
 * Romeo X Juliet eventually reveals that Neo Verona's prosperity (and continued existence) is contingent on.
 * Digimon Savers has the good Dr. Kurata, who removes the hearts of digimon in order to transform them into his Mecha Mooks, the Gizmon. It goes further
 * A quite literal (and disturbing, especially for a kids' show) application of this trope occured in another Digimon series, Digimon Tamers. The Big Bad D-Reaper is a mass of otherworldly energy which intends to slowly consume the entire world. Held captive at its core, though, is Juri Katou, a very young girl who is in deep despair over the death of her best friend and Digimon partner, which was the final and hardest blow to her after several years of quiet and hidden suffering started by her mom's demise. The D-Reaper is literally powered by Juri's misery.
 * Gundam X featured, as a minor plot point in its ocean Story Arc, a group of pirates who use special radar systems made from the brains of dolphins. By the end of the arc the systems are destroyed.
 * Maybe Powered By a Forsaken Child to you, but dolphins are complete jackasses.
 * Before this there was the MAN-003 Patulia, a Mobile Armor that required a Newtype (in this case, ) to operate its wired beam cannons. Said newtype was rescued before the machine could consume him.
 * Let's not forget how another newtype was sought after to force her lend her massive newtype powers to those who found her  . The Lorelei arc was focused on the Freeden crew finding said newtype first and saving her.
 * All of these devices are predated by Victory Gundam's Angel Halo, a huge Zanscare fortress that contains
 * Come to think of it... every single Mobile Suit piloted by a Newtype or an Artificial Newtype can be seen as such, to different degrees. Double if it's an artificial Newtype, as these people are specifically trained and experimented on to adquire Psychic Powers at huge health and mental cost.
 * The last use of this trope is seen in Gundam AGE,
 * In the non-canon crossover between Mobile Suit Gundam ZZ and Space Runaway Ideon, Neo Zeon planned to use seven-year-old Princess Mineva Lao Zabi and her Newtype powers to reawaken Ideon. All it did was piss off the mecha and force Amuro Ray and Judau Ashta to save her and put it down.
 * Project ARMS. Pretty much literally. Almost every Egrigori experiment uses a child as the test subject. Most prominent are the, the Chapel children who were given drugs while in the womb to make them super smart and work as scientists for the group, various mutant and psychic children taken to be soldiers, and Alice who was on the research team and . There's also the other ARMS teens, who were specially genetically engineered to be soldiers to take down the Egrigori.
 * The magic in the parallel world in Fairy Tail comes from the lives of the people from the normal world.
 * Elfen Lied has Number 28 and  The less said about how they operate, the better you'll sleep at night.
 * In Bokurano, the energy that fuels the Humongous Mecha is
 * Moreover, it's theorized (and strongly implied) that  The world of Bokurano is such a nice place, isn't it?
 * The Reverse Explosion system in Zero Zero Nine One, which is powered up
 * An episode of Betterman reveals that an "unmanned" mech is actually piloted by another character's "dead" baby brother - now effectively a Brainina Jar. Releasing him really does kill him.
 * A short anime called Hide and Seek had kids being hunted through an empty city, and when they were caught,
 * Its also strongly implied that
 * Rah Xephon. The huge mecha style beings attacking the city are in fact  There is a rather interesting plot twist in that  Cue angst.
 * Junior, from ROD the TV appears first as a mysterious, effeminate child antagonist, working as a secret agent for the British Library towards their heinous goal. He's lived a lonely life, and is automatically drawn to those that show him kindness. However, after his  it becomes apparent that Junior
 * In Dragonball Z, Paragus, in order to lure Vegeta into a death trap as revenge for his father nearly executing his family, had used Broly, his own son, shortly after placing a Hypno Trinket / Power Limiter on him, to blow up most of the Southern Galaxy in one fell swoop (enough planets in a short period of time to get King Kai to notice and commission Goku to locate and defeat the new threat). It is also implied in the flashback that Broly was unwilling to wear the Power Limiter/Hypno Trinket. Taking this into account, it really is no wonder why Broly would attempt to kill Paragus after his anger became powerful enough to release him from the device.
 * Then again Broly was a psychopath, anyway. While his father's use might fit this trope in the pure technical term, he was actually sparing the universe of Broly's might, rage and pure Ax Crazy-ness.
 * Actually, it was implied that he actually destroyed far more planets in the South Galaxy while Broly was under his control than Broly himself did when he was not controlled.
 * In Bleach, Aizen nonchalantly reveals that Also
 * In the Battle of the Planets episode 'The Space Beetles', the title mechas were powered by kidnapped children. Making the premise even MORE evil than the Science Ninja Team Gatchaman episode it was derived from (which simply used children's destructive instincts to direct the mechas).
 * In the Sailor Moon Super S movie, Queen Badiane wanted to use all of the children on Earth like this, kidnapping them and putting them on stasis to feed off their dreams.
 * Taken as literally as possible in Sword of the Stranger. The antagonists want to sacrifice Kotaro, an orphaned child, to make their emperor immortal.
 * In the Kikaider OVA series, an enormous doomsday device requires Dr. Gill's son to power it.

Card Games

 * Magic the Gathering has a whole color of this: Black. One common combo is creature removal (i.e., killing creatures), discard spells, and the Avatar of Woe, a huge creature which costs eight mana (two of which have to be black), but only costs the two black mana if there are a total of ten or more creatures in all graveyards.
 * It should also be noted that the whole concept of black mana is sacrifice for selfish, personal gain - even to the point of sacrifing bits of yourself. Perfect example - Necropotence.
 * Years before Necropotence was the Ur-example of self-sacrificing cards: Lich.

Comic Books

 * In the last post-Zero Hour volume of DC's Legion of Super-Heroes, there was a new galaxy-level faster-than-light spaceship drive introduced by the government of the United Planets. The Legion discovered that the drive power sources were living and sentient beings who had been created by the government via the abduction, torture, and genetic splicing of citizens of two of the United Planets' member worlds - and that being used to power the drives put them through agonizing pain and slowly killed them.
 * A Marvel Comics crossover storyline had the villainous Secret Empire capture Mutants to drain their greater-than-normal psychic energy to power weapons and vehicles to take over the U.S.
 * The events are later revisited in the short prose story "Firm Commitments", told from the point of view of a scientist who discovers the immense thermodynamics-breaking potential of Mutant neurons, gets involved with events far greater than himself, and has his life ruined as a result.
 * Dr. Doom permanently sealed his position as truly evil rather than arrogant Well Intentioned Extremist when he tracked down his first love, convinced her he had abandoned his technology and evil ways, then.
 * Well it would have been permanent had not every writer after these events pretended they never happened.
 * During the Messiah War X-Men storyline, an alternate future version of Kiden Nixon is used by Stryfe to empower a machine that prevents time-travelling.
 * In Elseworlds Finest, there is no Superman or Batman, the most powerful superheroes are their Distaff Counterparts, Supergirl and Batgirl. Batgirl is trying to take down Lex Luthor, and elicits a reluctant Supergirls help. They both travel deep underground Metropolis, trying to find the 'clean fuel source' that Lex Luthor discovered for the city years ago. It turns out that But considering that this is Lex Luthor, are we truly surprised he'd stoop so low?
 * The power rings of the death worshipping Black Lantern Corps of Blackest Night don't rely on emotions like the others. Instead they are powered by killing a lot of people. Killing a person and stealing their heart restores 0.01% power to every ring in the Corps. So it takes about 10,000 hearts to recharge all the rings to maximum power, minus the power used to steal those hearts of course. And when all the rings are charged to 100%,
 * Blue Mountain, home of the Gliders in Elf Quest, featured doors and ornaments that were maintained and controlled by rock shaper elves. Once free-willed elves, these rock shapers were so deeply sunken into meditation or mental numbness that they were oblivious to all but other Gliders' commands to open or close.
 * of Fables  in exchange for her considerable magical powers. In order to keep said powers,  . In modern times she has supposedly stopped   and uses   instead. It's heavily implied that she also maintains her magic by
 * Actually, some of the text from that part implies she
 * The Iron Man miniseries Hypervelocity reveals that the AI used for Life Model Decoys and elswhere in the Marvel Universe -- such as the Virtual Ghost backup of Tony Stark who's the series' protagonist -- was based on horrific human experimentation. The bad guys in the series are the Virtual Ghosts of some of the test subjects.
 * Iron Heights, the horrendous supervillain prison for the enemies of The Flash, is powered by Fallout, a man who was irradiated and accidentally killed his family. He is so irradiated that he needs to be quarantined so that his energy can be safely released. When the Flash first sees him, the process for powering the prison is extremely painful. He later makes the warden change the system so that Fallout is more comfortable.
 * This is oddly similar to The Dark Knight Strikes Again, where Flash himself is used to power an entire city, by essentially running on a giant hamster wheel all day every day.
 * Emperor Palpatine did this to maintain his immortality. To be exact, he dreamt of conquering the entire universe and drawing on the Force from every individual for the sole purpose of keeping himself, and possibly Darth!Luke alive for all eternity. And yes, all Sith are obsessed with immortality.
 * In an obvious shoutout to The Matrix, the American Sonic the Hedgehog comic features a new creation by Dr. Eggman/Robotnik after the Roboticizer is rendered obsolete: the Egg Grape Chambers. Eggman captures Mobians in them and uses their life force for power. This slowly drains their memory as well. Left too long, they can be killed, or at the very least left with amnesia of varying degrees.
 * The use of someone's life force for energy is also the principle behind the energy weapons and rockets built into Bunnie's robotic limbs. One enemy (the Iron Queen), who usurped control of her robotics, tried to use this to kill her via overexertion.
 * In the Mystique comic, there's a mutant who can control all machines and gets plugged into a giant device that requires her power to run. She's a little girl, of course.
 * DC Comics. Reign In Hell miniseries reveals one of the more feared punishments of hell was becoming a building materials.
 * Incorruptible. The Superman analogue goes quite insane after . Oops.
 * In Mark Waid's Empire, Golgoth
 * Give Me Liberty has secret experiments performed with schizophrenic kids. One of them turns out to be a telepath.
 * A plot point in Teen Titans had Deathstroke's team breaking up a drug manufacturing ring that created Bliss, a drug literally made from children. It's later revealed that the reason for Roy Harper's behavior while supposedly on heroin (supposedly in that there was no way a man on heroin would be able to fight like he was) was that Deathstroke was secretly spiking his heroin with samples of Bliss.
 * Secret Six: In the Villains United miniseries, the team is shown invading a power plant in a Southeast Asian dictatorship. A boy emitting solar power is hooked up to a machine siphoning the energy. They break him out, but leave him in the Mirror Dimension, on orders to make sure he is no longer a threat to American interests.
 * In the 2008 Guardians of the Galaxy series, the alien Universal Church of Truth powers its technology with "Belief Engines", generators that draw on the faith of its legion of worshippers. At least one of their starships is shown carrying storage banks full of the faithful, kept in stasis and wired directly into the ship's power systems.
 * The X-Men storyline that introduced the Broods established that the Brood's ships are made of the Acanti, huge alien life forms that float around space. The Brood capture them, lobotomize them and turn them into living vessels powered by pain.

Fanfiction

 * Aeon Natum Engel has a Patrone system being both using and used by Special Services sorcerers.
 * In Divine Blood most of Kodachi Kuno's power comes eating the minds of her mass produced daughters leaving their identities fragmented and their souls chained within hers.
 * Scapegoat is a Ah! My Goddess crossover (wouldn't do to spoil the cross) that explores this concept brilliantly.
 * In the Pony POV Series,
 * In Rainbow Factory, rainbows are made out of

Film

 * According to Warlock, one of the ingredients of a flying potion is the rendered fat of an unbaptised child. Even in modern times when there are alternatives, the character is from the 17th century, back when there were no alternatives. The potion is based on a (supposed) actual witches recipe of the era ("fat of unbaptised brat" even gets a mention in Shakespeare). Likewise the nail in the footprint has a real world source.
 * You can still extract fat from a kid without killing them via Liposuction
 * Arcade features a video arcade named "Dante's Inferno", where a new virtual reality arcade game called, boringly enough, "Arcade" is being tested. If you lose, you're trapped inside the game and die. Turns out the game is Powered By a Forsaken Child.
 * The boy was abused and, eventually, killed by his mother. The game designers decide it's a good idea to take a few thousand brain cells from the body and use them in the game.
 * Apparently, the game is somehow able to transcend virtual reality and enter Real Life. At first, it can only grab people who are in the arcade booth. Then, the game is ported to consoles, and the game is able to do the same thing in people's homes. At the end of the film, it looks like the boy projects himself on the street, meaning the game is becoming more powerful.
 * Soylent Green Also this trope's original namer.
 * In The Matrix, we're all Forsaken Children.
 * In The Animatrix it also becomes Fridge Horror when you realize this is Humanity's fault as well: The Machines originally ran off mostly solar power until some geniuses created the eternal night to try and shut them down for good. The Machines simply got creative and ironically green in their quest for alternate energy sources.
 * In Thirteen Ghosts the ghosts of the title are used to power some sort of demonic machine designed to open "the eye of hell"
 * Minority Report has a pretty literal version: the Precrime department's method of predicting the future involves three psychics, kept in chemically-induced dream state 24-7 and hooked up to a computer, so that the detectives can piece together visions of murders from their recorded dreams. Where does literal come into it? Well, it turns out that the Precogs are actually the abandoned, mutated offspring of drug addicts. Doubly frightening was the knowledge that one of the creators of the Precrime system was willing to kill the mother of one of the Precogs to ensure that they would stay Forsaken Children.
 * The first X-Men film has the machine that turns ordinary people into mutants powered by Magneto--but using it weakens the power source (likely killing him if he uses it on full power), so he forcibly has the power-stealing mutant Rogue absorb him and uses her to power the machine.
 * In the original draft for the movie, Magneto actually wanted to use Wolverine instead as a sort-of living antenna to amplify his powers, apparently due to his Adamantium skeleton.
 * And in the second movie, Stryker's mind-control serum is derived from chemicals secreted by the brain of his own son, Jason; though still alive and still capable of using his impressive powers of illusion, Jason's been given a lobotomy to make him more pliable and is confined to a wheelchair- complete with a shunt in the back of his head used for collecting the fluid.
 * In Monsters Inc., the entire monster society is powered by the screams of children. Later on, we get introduced to the Scream Extractor, which fits this trope even better by sucking out the screams of a single kidnapped child in order to gain more power. Thankfully it never gets put into mass use,
 * In Pirates of the Caribbean: On Stranger Tides, the ritual for the Fountain of Youth. When Jack finds out it requires a human sacrifice, he immediately finds his desire for the fountain "greatly lessened".
 * A Nightmare on Elm Street's Freddy Krueger's Nightmare powers are Fuelled by Children's fear and their Souls.

Literature
"From outside comes the clank of the Big Combination and the screams of the children who march, march, march on their bleeding footsies, running it."
 * The Hugo-winning short story "The Ones Who Walk Away from Omelas" by Ursula Le Guin is entirely about this trope.
 * In Steel, by Carrie Vaughan, the villain crafted a sword by quenching it in the blood of his own daughter.
 * In Black House by Stephen King and Peter Straub, the "Big Combination" is a gigantic city-machine powered by the slave labor of abducted children, and their collective screaming can be heard over the roar of the machinery from miles away.

"" "Any sentient mind will serve the purpose," said the Alayan. "Any mind with a grasp of reality and the ability to change reality through fantasy, if you will. We direct the fantasies so that they become real . . . and the vessel moves in objective reality through the pressure of the subject's mind. Unfortunately, that mind moves as well, in a psychic dimension from which it cannot be retrieved. We could use ourselves as subjects, but we do not do so while we have minds aboard which are not ours. That is the main value for which we trade.""
 * The Wamphyri in the Necroscope series use humans to build their warships, chthuluesque warbeasts, homes, plumbing, etc.
 * The Utopia in Ursula K. Le Guin's short story The Ones Who Walk Away From Omelas is  Its earlier inspirations make this Older Than Radio at the latest.
 * David Mitchell's Cloud Atlas contains a sinister example.
 * David Drake has two separate examples in one book, in Cross the Stars:
 * A settlement of Kettleman Bubble houses, which are luxury dwellings that can produce anything the people in it ask for, and use anything organic (but non-human) as raw material. The problem arises because Kettleman was a raving racist bigot who had a very narrow definition of "human" -- it didn't include Italians, for instance...
 * The Alayan space drive, which is based on warping the perception of objective reality in a sentient mind, eventually driving the "fuel" mad and useless.


 * In Harry Turtledove's Darkness Series, a high fantasy take on World War II, magic is charged from people's lifeforce. This leads to several scenes of soldiers charging their magic wands with their recently dead comrades, and eventually to the Germany-equivalent nation Algarve to round up Kaunians (people with blonde hair who they are highly prejudiced against) for mass killings to give its armies a major magical boost at the proper moment. This leads the USSR equivalent to retaliate by killing criminals and eventually just lower class citizens for its attacks, while the Japan equivalent uses volunteers from its armed forces.
 * In Mike Carey's Felix Castor series, the Satanist Church of the Americas, under the command of AntonFanke create "sacrifice farms" in order to have a regular supply of forsaken children for precisely this purpose.
 * In Vernor Vinge's A Deepness in the Sky, the Emergents' society is driven by the Focused; people who have had their brains reconfigured to make them obsessed with a certain subject, making them super-competent at that but unable to function in anything else, putting them in a sort of intellectual slavery.
 * In The Gone-Away World by Nick Harkaway, the world has been polluted by "Stuff" which responds unpredictably to human thought. Normal life is only possible in the neighborhood of a pipeline that pumps out the counter-agent, called FOX. The main character eventually learns that FOX is
 * The Harry Potter books have three:
 * Using the blood of a unicorn can keep you alive, but you have to kill a unicorn to get it. This also curses you for life, although the specifics of this curse are never explained; Firenze simply refers to it as a "half-life, a cursed life". Voldemort only uses it as a stop-gap on the way to his true goal.
 * The spell that restores Voldemort to full power requires the bones of his dead father, the flesh of a servant (Wormtail's hand) and the blood of an enemy (Harry).
 * Using a Horcrux to store your soul requires killing someone, and splits your own soul apart, leaving the other part in the Horcrux.
 * In Philip Pullman's His Dark Materials we find out in the last book that the Spectres (intangible soul eating wraiths and the series' Eldritch Abominations) are actually made by.
 * A more direct example from The Golden Compass was cut from the movie version: Lord Asriel was required to
 * That scene was still filmed and can be see on YouTube. It gives us the chilling line from Lord Asriel, "The life of one child does not matter. Not when freedom is at stake."
 * Similarly, in the David Brin novel Kiln People the Big Bad's plan depends on
 * This is also one of the plots of the The Illuminatus Trilogy, where many of the aging higher members of the Illuminati intend to become transcendentally Illuminated, that is, immortal disembodied spirit-beings, by  and used to achieve immortality. They're stopped when  . Yeah, it's an odd book.
 * In the Nightfall novels, the Hitman With a Heart protagonist and other characters in the universe are some form of metahuman (like the Mutants of the X-Men). Sorcerers in this world gain their powers by murdering these mutants and stealing their innate power, and the magic involved results in the slain being trapped in torture for all eternity. Thus, sorcerers are by nature evil in this universe, and the villain of the first novel is an Evil Chancellor who has become very powerful by killing a number of metahumans.
 * Literal in Tamora Pierce's Protector of the Small series.
 * The science fiction novella Thor Meets Captain America, by David Brin, is not about Superheroes. It proposes that the Nazi death camps were an attempt to practice Necromancy on an industrial scale, and it is set in an alternate world where it worked; the unprecedented amount of deliberately imposed death and suffering has brought the Norse gods to reality, on the Nazi side. The invasion of Normandy was completely destroyed and a stalemate ensued. Fortunately for the Allies, the invocation was so authentic that Loki the Ever Contrary defected. The most depressing part is that this still makes more sense than the real version.
 * This same theme is used in The Atrocity Archives, by Charles Stross. In this case, the Holocaust was part of a Summoning Ritual to bring an Eldritch Abomination to the aid of the Nazis. In true Cosmic Horror Story style, the thing they were trying to bind to their will was just a teeny, weeny, eensy bit more powerful than they had suspected. They were stopped, but a modern day cultist opens a portal to a reality where they succeeded. Hilarity fails to ensue.
 * The Expanded Universe Star Wars novel The Truce at Bakura involves a race of aliens who steal sentient minds to operate their weapons.
 * Oh, it's much worse than that. The entechment souls both powered and controlled the systems they were hooked up to, leading to unbearable misery as your soul was sucked out to power the guns you were forced to fire.
 * In Venus on the Half-Shell by Kilgore Trout (Philip Jose Farmer, NOT Kurt Vonnegut), the interstellar drive works by painfully draining the Life Energy from beings in another universe. The faster you went, the louder the wailing you heard coming from the engines. At the end of the novel,
 * In the Dark Tower's Wolves of the Calla, it's revealed that the bad guys' captive psychics are being fed a substance to boost their powers. That substance is withdrawn from the brains of kidnapped twin children, one from each pair, leaving them mentally slow, unnaturally big and doomed to die young.
 * Dracula -- and most other vampires since him -- have to drain the blood, or life force depending on variation, of living people just to survive.
 * Lightbringer, Azor Ahai's sword from A Song of Ice and Fire, which the smith tempered by plunging it into the heart of his beloved, killing her horribly.
 * Most major magic in the Ice and Fire universe seems to have some element of this: a repeated statement is that "only death can pay for life" when performing blood magic. That includes
 * Employees of The Pilo Family Circus are paid in bags of mysterious powder that, when melted down and drunk, can grant wishes. It's later revealed that every grain of this powder was once part of a human soul, extracted from the Circus' audience.
 * Subverted by Alastair Reynolds in the short story Weather. Conjoiner drives include living, thinking human brains as an integral component, to calculate reaction pathways--but Conjoiners consider this a high honor and an enjoyable experience (so long as the drive's working right.) It's something akin to a challenging video game.
 * Myrddraal swords in the Wheel of Time gain their exceptionally lethal properties from an exceptionally unpleasant process. After being quenched in a black river that would be lethal even to the rock golems that make them, they're finished off with a human soul. They are implied to require regular "topping up."
 * In the Otherland series, the network is
 * In The Black Wind, a novel by F. Paul Wilson, the titular "Kuroi Kaze" or "Black Wind," a hideous black cloud that kills all living things, is powered by a child's death. Preferably a "mixed heritage" child (i.e. a child of mixed race.)
 * In the Myst novel The Book of D'ni, the beautiful realm of Terahnee is secretly sustained by the ceaseless labors of millions of mind-numbed slaves, kept out of sight in underground warrens. Atrus is horrified to learn his own innocent request that an entertainment device be run at high speed has killed dozens of men and women, worked to death to power an apparatus he'd assumed was engine-powered.
 * More precisely, it was another member of his expedition, Marrim, who made the request.
 * In the Nightside, Forsaken Children are fairly standard-issue sources of power for villains. In Nightingale's Lament, for example, John Taylor discovers that  Passing references to ambulances powered by human pain are used simply to set the mood of the neighborhood.
 * In the opening sequence of Just Another Judgement Day, Dr. Frankenstein uses counterparts from another dimension to provide the local party people with eternal youth through an arrangement similar to Dorian Gray's.
 * In Timothy Zahn's Deadman Switch, a planetary system is discovered that's full of extremely valuable minerals...but there's a field around it that shuts off FTL travel, so there's no practical way to get in. Unless, as it turns out, you have a freshly dead corpse in the navigator's seat. No, this doesn't cause people to write the place off, don't be silly. They just start using convicted criminals...
 * It's slightly more disturbing when you realize the other consequences. Like the fact that the initial research team only got their because while investigating the "cloud" their navigator had a fatal heart attack... and once they figured it out, they had to draw straws for who would die so they could make the return trip...
 * In Interworld by Neil Gaiman and Michael Reaves, the ships used by HEX and the Binary to move between worlds is powered by the life essence of captured Walkers. At least in the case of HEX, they first boil away all unnecessary parts, such as your body - while keeping you magically alive through the entire process.
 * In The Sword of Truth books, in order to get into the world of the dead and back alive, you had to (minus the incantations):
 * In David Farland's Runelords series, anyone can acquire magical upgrades to their senses, strength, intelligence, speed and so forth with magical "endowments." The catch? Endowments don't create ability, they just transfer it from one person to another. So you can have the strength of two men, but in order to provide it there's got to be another man lying in a bed somewhere who's too weak to even raise his own arm because all his strength is being funneled to you. To receive an endowment of wit (intelligence) is to literally convert someone else's brain into an extension of yours. Now consider that nobles often have dozens of endowments...
 * In the Mithgar books, a mage literally has to give of their own soul to work their magic, causing them to age dramatically (though they can then go into stasis for extended periods to recover lost youth). Black Mages, on the other hand, find this process cumbersome and inconvenient, so they power their magic with other people's souls, generally wrenched from them through acts of tremendous mental and physical cruelty. As this process is implied to become somewhat addictive, there's a reason most Black Mages end up insane Complete Monsters.
 * In American Gods we encounter one small Midwestern town with none of the problems of young the folk moving away and aging populace and unemployment, crime, and drugs that plague the region. Wanna know what the town's guardian god has to do to keep  the "one good town in these parts"? Three guesses, and the first two don't count.
 * Not only that, but hundreds of years ago
 * In Simon R. Green's Deathstalker series, the Darkvoid Device turns out to be one of these... powered by
 * In the Vorkosigan Saga by Lois McMaster Bujold, there is House Bharaputra, a clan/business on the disreputable world of Jackson's Whole. They specialise in cloning and genetic engineering, and most notably provide a rejuvenation program for the very rich: clone them, brainwash the clones so they won't fight it, then transplant the brain of the original into the clone.
 * In the Gemma Doyle Trilogy, someone without power of her own can get a warped version of it by performing a sacrifice. This is what  try unsuccessfully to do to , what   almost does to a deer, and what   does to  . This is either part of the reason for her corruption or a result of it.
 * In the Secret Histories series by Simon R. Green, specifically in The Man With the Golden Torc, Edwin Drood uncovers his family's greatest secret:
 * In The Laundry Series by Charles Stross, many of the Laundry's weapons are made this way. Standard issue Hands of Glory are sourced from political prisoners in China (they tried using chimpanzees for a while, but there was less bang for the buck and animal rights activists got involved). The construction of the Violin that Kills Monsters required the torture and murder of twelve innocent people. (They investigate the feasibility of making more like it, but "Just owning the necessary supplies probably puts you in breach of the Human Tissues Act of 2004, not to mention a raft of other legislation.") The ritual for binding the Humanoid Abomination codenamed TEAPOT calls for the blood of babies.
 * In the Chanters of Tremaris trilogy, the Palacae of Cobwebs, a beautiful and delicate structure that looks like it's, well, made of cobwebs, is the home of the Emperor of Merithuros and his court. Unbeknownst to its inhabitants, the Palace cannot actually stand and must be continually chanted into being, day and night, by five children, all of which have had their legs broken and never set properly so they are unable to escape.
 * This is given chillingly realistic form (if you ignore the economics of it) in Never Let Me Go, where the characters are clones kept to provided transplant organs, and are so conditioned that they don't even think to fight the system.
 * In CS Friedman's Magister Trilogy, magic is harnessed by making use of one's life force. While normal witches wind up prematurely aging and dying while still relatively young because of this, the Magisters themselves figured out a workaround for it. Simply put, they link themselves to the life force of some complete stranger elsewhere in the world. The mere mortals have no idea that they're being used by the Magisters, believing that people who are linked in such a way are suffering from some horrible disease that even a Magister is not able to cure. Needless to say, fledgling Magisters have been hunted down and killed by their teachers in order to keep that little fact a secret.
 * Many forms of Black Magic in The Dresden Files rely on torture and death to power them, with the Darkhallow in Dead Beat being perhaps the most extreme. It involves the sorcerer
 * The heroine in Lynn Flewelling's Tamir Trilogy is hidden from a King Herod style massacre of the innocents by a Gender Bender spell powered by sacrificing her twin brother at birth, an act of necromancy so horrific it has consequences that last for years and eventually causes all of the witting participants to meet untimely and grisly deaths.
 * In Warbreaker, all magic is powered by breath. Each person has one breath, the loss of which saps creativity, harms the immune system, and can lead to mild depression. People can voluntarily give their breath to others, so poor people often sell theirs to the rich. Most magic takes upwards of 20 breaths to accomplish, and some people have more than several hundred.
 * The "gods" of the series, the Returned, each need to consume one breath per week or they die. The donor is often a child since their breaths are considered better than that of the elderly.
 * From Mistborn by the same author, Hemalurgy, one of the three core magic systems, works on this principle. Its use involves trapping a portion of someone's soul in a metal spike and then sticking the spike into someone else, endowing the recipient with superhuman abilities via the stolen life-force (what, exactly, is transferred depends on the kind of metal the spike is made of and where it's placed on the recipient's body). Oh, and so far as we know, it's not possible to do this without it being fatal to the unfortunate "donor".
 * In John D. MacDonald's Ballroom of the Skies, the galactic government deliberately keeps Earth impoverished and war-torn ... because that toughens Earthpeople spiritually to the point that they make good recruits — to run the galactic government.
 * One Animorphs book has a controller who's discovered a way to avoid returning to the pool every three days. He eats his fellow Yeerks, killing lots of human controllers to get them.
 * One Animorphs book has a controller who's discovered a way to avoid returning to the pool every three days. He eats his fellow Yeerks, killing lots of human controllers to get them.

Live Action TV

 * "Stargate SG-1" had tretonin, a drug that granted the user perfect health-but had a side effect: the drug destroys the immune system, rendering the user dependent on the drug forever. The SG-1 team, after beginning negotiation for some of the drug, learn that the drug is actually created from the offspring (read babies) of a Goa'uld queen the Pangarans discovered in a stasis jar. normally this would not be so bad considering the Goa'uld are the series' Big Bad and they are parasite that force there way into human's brains and take over their bodies while most likely applying eternal mental torture to the host mind, but much later, after the Tok'ra (the rebel faction of the Goa'uld who were allies with Earth) are brought to help analyze the drug, it is discovered the Goa'uld queen is actually the Tokra's long lost queen (and their last hope of reproducing as their number are dwindling and she was the only known Tokra queen). Naturally the Tokra object to such treatment of their queen.

""You mean... you're shooting up on ?""
 * Babylon 5 had an immortality drug that required killing people to manufacture it.
 * The Shadows use living beings, suitably adjusted, as the control units for their spacecraft. They also use people to grow some of their technology, according to one of the canon novels. It's not stated whether this kills the people on whom the stuff is growing or not, but it's not a pleasant process.
 * Babylon 5 also contained the alien healing device, which can cure any wound or illness but only by siphoning life energy away from a healthy being (its creators used it as a means of "just" capital punishment, taking their life to insure somebody else got to keep theirs).
 * The Buffy the Vampire Slayer episode "Doublemeat Palace" leads the viewer to believe Buffy has encountered a Soylent Green-type situation -- only to move on to a more realistically plausible, but equally strange-feeling twist.
 * The Season 8 comics have
 * The First Slayer herself is essentially a forsaken child forcibly infused with demon energy by magicians. Essentially true of all slayers.
 * Cleopatra 2525's robotic oppressors of humanity were revealed to be slightly less robotic than believed: They're cyborgs, using brains harvested from human children.
 * HBO aired Cosmic Slop, three short supernatural stories hosted by George Clinton. One story was about a fleet of aliens arriving to earth and offering to solve all of the world's current problems. In return for all of the people of African descent who do not pass the 'paper bag test'. Did they get their price? In a heartbeat!
 * In the Doctor Who episode "Revelation of the Daleks", Dalek creator Davros offers to help solve a galactic famine problem. How convenient that he's set up shop on a cemetery planet...
 * In "Remembrance of the Daleks",
 * The Toclafane in The Sound of Drums / Last of the Time Lords, who the Master uses as his personal army of Happy Fun Balls, can be considered part of this trope.
 * "The Girl in the Fireplace": "We lacked the parts."
 * The Controller in "Bad Wolf"--although she's an adult when we see her, one of the minor characters explains she was "installed" when she was five years old.
 * She's also the only one who knows about the villain and their evil plan, but she can't say anything about it until a coincidental solar flare cuts her off from their control.
 * In "The Beast Below",
 * Also subverted in that
 * Classic Who, Fourth Doctor, "Warriors' Gate": Rorvik's culture has spaceflight dependent on wiring a time-sensitive slave into the navigation systems and hitting that slave with high voltages.
 * In Fringe: Time Travel has the unfortunate consequence of killing everything and everyone within the immediate vicinity of the destination, dependent on the length traveled.
 * "Walternate" was building some sort of Doomsday Device to destroy our universe that he intended to be powered by . , you really begin to wonder which Walter is the bigger monster.
 * In Torchwood: Children of Earth,


 * The way Torchwood fights back
 * And it happens just when you think things can't get any darker.
 * Almost all the cursed artifacts in Friday the 13 th The Series.
 * In Heroes, the Big Bad of the first season, Sylar, is capable of "acquiring" the superpowers of others through an unshown (until the beginning of season 3) procedure that requires killing them and removing their brains.
 * Technically he doesn't have to kill them to do it as he learned in volume 3. However the quickest route to it is studying the brain and (Unless the victim has a healing factor) the process of slicing their head open is shown to be fatal.
 * It's implied in a later volume that he knew even before volume 3 he could absorb powers through empathy. He just liked knowing every little thing about the power, and the life of the person who had it meant little to him.
 * Sakurai Yuuto, aka Zeronos in Kamen Rider Den-O has people around him lose their memories of his future self every time he transforms. When that turns out to be insufficient, then he gets his new Zero Form, which is powered by peoples' memories of his current self (this after nearly disappearing completely after his past self is killed by an Imagin).
 * The first season of Lexx, also known as "Tales from a Parallel Universe", was made up of four movies. The second movie, "Eating Pattern", revolved around a junkyard planet where bodies could be made into a highly addictive drug called "Pattern". The title Living Ship also eats planets, occasionally including inhabited ones.
 * Let alone growing the Lexx in the first place; prisoners from all over human space (most of whom had only committed fairly minor offences) had their major organs cut out by circular saw (to make robotic drones, apparently?) and the rest of their body was shrinkwrapped and fed to the Lexx. All it has to say on the matter was that "The food was good there".
 * And even later,   received the same treatment; becoming food for.
 * The Otherworld episode "Paradise Lost" had a immortality drug called Kaloma that was created by draining the life force of human beings.
 * Star Trek Voyager had another ship trapped in the Delta Quadrant - with an enhanced warp drive that burned alien Energy Beings to get them home.
 * In an episode of Masters of Horror entitled "The Fair-Haired Child", the plot involves a grieving couple appealing to an otherworldly force to resurrect their dead son. They in turn, have to feed him ten children.
 * The child shows his um...gratitude to them in a similar way O_O
 * The Attic from Dollhouse is first introduced as a classic And I Must Scream scenario. What it actually is, however, is much worse:
 * In an episode of The Invisible Man, an eminent neurologist is removing pieces of homeless people's brains in order to cure those he considers more worthy who've suffered brain injuries.
 * He gets proper justice in the end - he falls off the stairs to his death. Since he's an organ donor, his own brain serves to cure one of his victims.
 * Power Rangers RPM, or more acuratly "invented by a forsaken child." Everything from  to the Ranger suits and Zords were created by Dr. K.
 * In one episode of Sliders, the characters stumble upon a village with its own Fountain of Youth. Which is the excretions of a gigantic mutant worm...whose primary diet is people.
 * An episode of The Worst Witch has Sybill turning a torch into a magic lamp that will grant any wish. The catch is however that it'll absorb energy from other things to grant each wish. When it runs out of plants to absorb, it starts to drain the girls and the teachers instead.
 * in Battlestar Galactica Reimagined, President Roslin's cancer is cured by . Thankfully, they don't need all of it.
 * An episode of First Wave had Cade stumble upon a Gua-run hospital, where they were helping some people... by giving them parts from other people's bodies. None of this was altruism, of course, but merely just another experiment.

Music

 * ORPHAN TEARS by Your Favorite Martian
 * The Vocaloid song Kagome, Kagome heavily implied this.
 * London Bridge is Falling Down

Tabletop Games

 * Paranoia has this when you ask what the incredibly Dystopian society is eating. Depending on the version, it's everybody who dies, or everybody who dies who wasn't Blue rank or above. Including children. (Or just bland things like algae and synthetic protein, but even then, people accidentally falling into food vats is disturbingly common.)
 * All Arcane (non-Badass Normal) powers in Deadlands work this way. The setting has it as an explicit rule. The soul involved is inevitably your own.
 * Except for Blessed and Shaman powers, which only require adherence to your religion and (in Shamans' case) proper rites. You still do the sacrifice, but it's voluntary and only involves limiting yourself.
 * While not known in Deadlands: The Weird West, it is common knowledge in the Wasted West that
 * The game Fairy Meat (a spin-off from the Knights of the Dinner Table comic) involves characters eating parts of each other to regain health.
 * In Magic the Gathering, Urza collapsed Serra's Realm, killing everyone inside, to activate the powerstone core of the skyship Weatherlight.
 * Also from Magic, all colors have some sort of ubercard that's cheap to use but has some drawback. Black, however, is the king of this, with a hideous amount of cards that allow one to do quite a lot of awesome things, but cost you creatures, land, life, cards in hand, cards in graveyard (a viable resource for black, so not something to be sneezed at), or something else (one example makes you lose the game if you don't win by the end of your next turn!). A notable early example: Lord of the Pit, an extremely powerful creature for its cost that requires a sacrifice of one creature per turn or it turns on you.
 * Not to forget that black's ways of regaining life generally involve taking it from others, as per the classic Drain Life spell...
 * Nuts to all that. The ultimate archetype is Necropotence which allows the player to trade life for more magical power and knowledge (i.e. draw cards). This card was so powerful it has been banned or restricted in most formats.
 * During the Invasion block, when Urza led a group of planeswalkers into Phyrexia to destroy it, he powered the bombs he planned to use with the soul of the planeswalker he expected to betray them.
 * Justified, since he was right.
 * Dungeons and Dragons
 * The 2nd Edition Spelljammer campaign setting had the Lifejammer helm, a magical device that allowed ships to travel through space by draining the life energy of creatures placed within it.
 * Too many examples in Ravenloft to mention them all; perhaps the nastiest was Azalin's Doomsday Device, powered by the stolen souls of his murdered enemies and the collective life forces of every living thing in Il Aluk, greatest city in the game setting. Also featured in Dance of the Dead, a Ravenloft novel, in the form of an enchanted riverboat powered by captive fey and magical beasts.
 * In Birthright, wielders of bloodsilver weapons can kill other beings to steal their bloodline powers.
 * The creation of permanent enchantments in AD&D involved the decrease of the Constitution attribute. The Forgotten Realms setting has the Blood Link spell, which allows the vitality of another sentient creature instead of the caster's own to be sacrificed for permanency (though this could compromise alignment, like most lifeforce-draining effects). Which also explained how drow and Red Wizards got tons of magic trinkets.
 * Continued in later editions, with slight modifications. In Third Edition, permanent magic item creation requires spending XP. Note that XP and levels in this game represent life-force: many vampires and similar creatures literally drain your levels when they feed.
 * In the Dark Sun setting, use of arcane magic, by default, drains life force from the environment around you, killing plants and leaving the soil infertile for years. Widespread use of such magic led to the world of Athas becoming a desert wasteland. Magic users who embrace this are called Defilers; those who learn to use magic without harming the environment are called Preservers. The respective advantages and drawbacks of Defiling vs. Preserving varies from edition to edition. In second edition, Preservers advanced in power more slowly than Defilers. In fourth edition, Defilers can drain life force from their own allies to empower their magic.
 * The Book of Vile Darkness supplement (basically featuring all the most evil stuff in the game, to help the DM make villains the heroes will really hate) features a foe called the Dread Emperor who uses this trope. He wears special golden armor that has four small children attached to it by lengths of chain. When hurt he can drain life from the children to heal himself. Players wishing to take him down (and who wouldn't?) must find a way to deal with this or risk sacrificing four innocent lives in the process.
 * The book also includes the Soul Eater prestige class, which allows the player to gain strength and abilities by bestowing negative levels on their enemies, essentially draining their life force. The player can eventually take their victim's appearance and all of their abilities if they kill someone this way.
 * In the Warhammer 40000 universe, the Imperium of Man has the Astronomican, a giant psychic beacon essential for warp travel. Originally powered by the Emperor's immense psychic strength, the device is later powered by the souls of ten thousand psykers (daily) trained for the purpose. The Astronomican's extreme psychic energy requirements cause the psykers' deterioration and death in only a few months. A constant stream of sacrificial psykers is therefore required to power the Astronomican.
 * Although at least the psykers who power the Astronomican are trained, and see the giving of their lives as their last and greatest duty. A similar process of soul-draining is used to feed the Emperor, and their compliance is... not so neccessary.
 * In the Ciaphas Cain novels, there is a mention of "tasty, nutritious Soylens Viridians."
 * It's also implied that the longevity treatments that allow even Puny Humans with enough wealth or ranking to live for a few centuries are made from children. Even sympathetic and otherwise heroic characters are known to use them, just to show how fucked up the setting is.
 * Depends on which type of juvenat treatment it is: they apparently range from synthetic/cybernetic organ replacements and plastic surgery through to (implied) fetal stem-cell therapies. There is one variant noted in the early fluff which involved cloning a person, applying some phlebotinum to cut-and-paste said person's soul into the clone, then spending a couple of decades (re-)teaching it skills and brainwashing it to think it was the original. Sure, it runs afoul of the Continuity Problem, destroys the soul of an innocent and wasted 20 years back in school, but hey, what with the other treatments out there, this body's good for another 2-3 centuries or so...
 * In addition to preying on humans to sustain themselves, the vampires of Vampire: The Masquerade can perform diablerie - feeding on their elders to improve their generational status.
 * Then again, their elders tend to be homicidal maniacs, stark raving crazy or complete monsters. And of course, every vampire's afraid of the day the Elders (note capitalization, they're that old) are going to rise again, eat every last one of their children and generally be bad for the neighborhood. So, killing older vampires is a "sacrifice" many younglings are willing to make. As soon as possible.
 * In Genius: The Transgression, materials like these are called Larvae. They constitute any item which invoked an Obligation roll to obtain, and offer increases to efficiency. Earlier editions followed up the section on Larvae with the quote from Doctor Orpheus at the top of the page.
 * In Werewolf: The Apocalypse, most supernatural items known as Fetishes (no, not that kind) are powered by a spirit that's permanently bound into the item. While most werewolves prefer to strike a voluntary bargain with a spirit, others may skip the "voluntary" part...
 * Characters in Mage: The Ascension with enough skill in the Spirit sphere could do the same thing and were considerably more likely to substitute coercion or brute force for diplomacy.
 * Since Vampire: The Requiem (Masquerade's reboot) doesn't have the concept of 'generation', it handles eating other vampires differently: if you chow down on someone more powerful, it boosts the power of your blood, expanding your capabilities. Sufficiently potent vampires, however, end up needing to feed on other vampires to survive.
 * Speaking of Vampire: The Requiem, there's a Trope Codifier for this trope in the form of the Belial's Brood faction known as the Mercy Seat. They are based on gnosticism and believe that the world is evil. It is possible to leave this evil world and reach a higher realm of existence, but in order to do so, they must basically damn someone to hell in order to rectify a cosmic imbalance. The more innocent the sacrifice was, the better the chances of leaving this world. Allegedly. The fact that there's a bunch of evidence, both in mechanics and fluff, to back their assertions up is another trope.
 * In Mage: The Ascension, it was possible to extract quintessence (the energy that makes reality real) from the life force of a willing creature. Many mages use their own life force. Some use specially reared livestock. A few villains use specially raised children. (A larger number of villains will attempt to use unwilling sacrifices, but this creates enough "resonance" opposed to the intended effect that it cancels out any potential benefit. They either don't notice, or don't care.)
 * The Mage: The Awakening Sourcebook detailing the Seers of the Throne includes their special servitors. The Myrmidons are fairly standard inborn Super Soldiers (although they are cursed to have to follow any command given to them in a certain language) and the Hive-Souled are Exactly What It Says On the Tin. The Grigori (a kind of ghost spy which can sense and follow the connections between people and things) and the Hollow Ones (people who can have their personalities rewritten) on the other hand are created by wrapping a person in a shroud which tears out their mind and reworks it, and exposing someone to an Eldritch Abomination which eats the part of their soul which lets them have any semblence of individuality (and the personalities they can be given are inevitably temporary), respectively. Neither process can be reversed.
 * And, as in Ascension before it, a mage can gain Mana from sacrifice. Most sacrifice their life force or their physical capabilities (both eventually get restored), but they can also sacrifice other living creatures. Trouble is, to do so they have to kill the victim - and humans give more mana than animals.
 * In Wraith: The Oblivion, the spirits of the dead -- which would include the characters -- can be boiled down and forged into anything from furniture to money. If that weren't bad enough, the unfortunate victims used to make this "soulsteel" remain conscious, and those who carry soulsteel items can occasionally hear them weeping.
 * In Exalted, the magical material known as Soulsteel is...well, filled with the aware, agonizing souls of the imprisoned dead (not surprisingly, Wraith was a big influence on Exalted's Underworld).
 * And Starmetal is made out of the bodies of (usually) minor gods, although in this case the gods in question are not conscious (with one non-painful exception).
 * Perhaps the most literal case in the setting is the phylactery-womb, the device that the Yozis use as the staging point and storage device for Infernal Exaltations. Her name used to be Liliun once, and she was . Now she's been twisted and violated in a number of senses, left barely lucid and babbling, just so that she can serve as the perfect receptacle for the Infernal shards.
 * Her Dad, however, has never stopped trying to find her, and when he finally does? Well, the Dad happens to be part of The Realm...and he hired one of the Anethema (A Lunar Exalted, which the Immaculate Faith teaches are evil monsters) to get his daughter out of Hell. He was willing to throw his lot in with creatures he THINKS are insanely evil, who he's fought against his entire life...Just to get his little girl back Betcha' the Ebon Dragon didn't see THAT coming!

Video Games
"Zelos: This is the grand Tethealla Bridge, powered by FIVE THOUSAND EXPHERES."
 * In Bio Shock, the Plasmids are marvels of superscience that give powers from generating electricity, to telekinesis, to shooting swarms of angry wasps from your arm, through genetic engineering far ahead of their time -- or our time. But to obtain ADAM, the Applied Phlebotinum needed to make new plasmids, sea slugs have to be implanted into little girls -- it must be little girls, for reasons that are never explained.
 * At some point shortly before the beginning of the game, a plasmid has been developed that will allow someone to destroy the sea slug from within, yielding a considerably lesser amount of usable ADAM but rendering the girl a normal human being again.
 * In Breath of Fire 4, The Empire has a long range "hex cannon" that's powered by torturing people to death, and does more damage the stronger the connection between the victim and the target. Normally this is used as a weapon of mass destruction powered by prisoners of war.
 * In most versions of Dwarf Fortress, dwarves will occasionally enter a "Fell Mood" - leading them to kill a nearby dwarf, process his carcass in the nearest Butcher's Shop, and turn it into an artifact. This being Dwarf Fortress, nine times out of ten it's something like a dwarf-bone scepter decorated with an image of a dwarf-bone scepter in dwarf leather.
 * ... adorned with hanging rings of dwarf bone and menacing with spikes of dwarf bone.
 * Also, this being Dwarf Fortress, the other dwarfs don't freak out when one of their number starts murdering people. It's more a case of "Hey, what a neat scepter!"
 * To the point where tons of engravings, sewn images, et al. will be made to celebrate the creation of this fine dwarf bone scepter. Again, this being Dwarf Fortress...
 * Heroic spirits in Fate Stay Night agree to fight in the Grail Wars because they believe it will grant them a wish, usually to let them live a second life or fix a past mistake. However, However, very few of the main characters actually know this while competing, possibly only Ilya and Zouken Matou.
 * Mind you,
 * have another (and very literal) use of this trope going straight into horror, no questions asked.
 * Final Fantasy IV's Dark Knight Cecil and the Fake King have a few shadows of this. The former's Dark Knight Armor is aparently powered by Cecil's own Spirit (it actually reduces the stat), while the King's first mission is to destroy a town to gain power.
 * Final Fantasy V's Job Crystals are apparently the souls of past Light Warriors. Yup, those crystals you use to change class are the crystallised souls of your predecessors. Still want to finish your quest so bad?
 * Final Fantasy VI's Magitek and Magitek Knights come from draining a still-living Esper, and siphoning its power into weaponry and human soldiers such as Kefka and Celes. The very Magicite that the player characters can equip and use in order to learn magic and enhance their skills is actually the crystallized remains of a dead Esper -- to the point that many living Espers deliberately reduce themselves to Magicite either to strike back at The Empire or to assist the party members, but the latter never show any regret for using the crystals.
 * Final Fantasy VI's World of Ruin is created by 3 statues sacrificing, well, everything.
 * Final Fantasy VII has this on a global scale. Mako Energy is powered by the life of the planet, or the latent life force that is currently cycling around waiting to be reborn.
 * In a similar vein, and with a similar refusal to stop using the Powered By a Forsaken Child Applied Phlebotinum, in Final Fantasy VIII,
 * Additionally, the final Guardian Force, Eden, has an ability called Devour, which enables Eden's host to eat his or her opponent in order to gain various benefits from HP to stat increases - although depending on the opponent, the effect could be negative instead. Either way, the game cheerfully acknowledges the rather Squicky implications of this: the animation for the ability involves cutting to a screenshot of a serene landscape, over which is played the very loud, messy slurping and smacking noises of the target being messily eaten. Bwahahaha.
 * Final Fantasy IX has Quina the Blue Mage. To learn blue magic spells, s/he has to eat the enemy. His/her weapon? An oversized fork. Additionally, the fuel everybody uses to power airships, Mist, is made of souls barred from the afterlife, but it's never made quite clear whether they're actually consumed in the process.
 * Each summonable creature in Final Fantasy X is powered by a different Fayth, Look at the lovingly rendered  They're really quite lovely.  Somebody put real care and artistic vision into those, which is morbid beyond belief when looked at in this context.
 * The Fayth are on call for the summoners at all times;
 * Final Fantasy X-2's Dresspheres are created from memories of past people, in fact Yuna being overcome by the memory of the Songstress Sphere is a major plot point. Now keep in mind there are about 40 of these dressspheres, most of them created by Shinra 'during' gameplay.
 * In Final Fantasy XI, learning blue magic involves "absorbing" the "essences" of monsters. Translate the euphemisms yourself. Furthermore, it's dangerous to do this, as a blue mage grows gradually less human as they gain more spells. It's implied that any character who actually does pursue the path of blue magic is amoral and ambitious.
 * Now consider the fact that likely ninety percent of the Player Characters have unlocked Blue Mage as a job class. Now consider that roughly half of those have likely spent any amount of time leveling it.
 * In Final Fantasy XIII, . Of course, this gets more complicated when you find out that.
 * Wasn't the entire point that
 * This appears pretty often in Heroes of Might and Magic V. The Necropolis Town has a building that can convert living units into Undead. There's an adventure map building where a Hero can sacrifice units in exchange for experience. The Demon Lord Heroes' "Consume Corpse" ability removes dead creature stacks from the battlefield to replenish mana. The Stronghold faction introduced in Tribes of the East owns this trope though. First, there's the "Slave Market" town building that lets you sell units for resources (ironic, given the Orcs' history as oppressed slaves). The Wyvern Upgrade, the Pao-kai, can consume dead creature stacks to heal and revive their own numbers. Their strongest unit, the Cyclops, can use Goblins (the weakest unit) as food and ammunition, making the poor saps literal cannon fodder. The Shaman upgrades, the Sky and Earth Daughters, are both able to sacrifice Goblins to replenish their own mana. In fact, this is the only way the Sky Daughter can use her "Chain Lightning" ability since she doesn't start battle with enough mana to use it. Her in-game creature description ends with this little gem: "Because of this, they are greatly feared by their opponents - and by Goblins". Not to mention that the Cyclop's description mentions that the Orcs bought the Cyclops' allegiance by offering them their favorite food: Goblins. Yeah, Goblins are pretty much the Stronghold's Buttmonkeys.
 * In Neopets, Caption Contest #214 featured this alarming image. Knowing TNT, though, it's probably a joke.
 * The manual for the RTS Earth 2150: The Moon Project contains several essays to bring the player up to date with the plot. One of the more memorable ones is a request for asylum from a disillusioned soldier formerly of the United Civilized States military forces, describing how the cyborg battalions of the last war disappeared only just prior to the invention of a portable AI module, large enough to store a human brain and a few electronics, that also has a very large warning stating the type of execution awaiting anyone who opens it. In another essay this is alluded to, as well as praising the soldier for anticipating the turn of events and defecting.
 * In Overlord, your armor and weapons are forged with fires fueled by the deaths of your minions, not that you care.
 * In Planescape Torment, . Naturally, the people this happens to aren't terribly happy about it:.
 * In the Neverwinter Nights 2 expansion Mask of the Betrayer the player is afflicted with a curse that makes him or her hunger for spirits, and able to choose to increase his or her power by eating said spirits. In addition to being obviously morally questionable, spirit-eating on a regular basis also has the downside of increasing the player's hunger to the point that he or she requires multiple spirits per day just to keep from dying.
 * Obsidian is REALLY fond of this one, it seems. In the second Knights of the Old Republic, the Jedi Masters explicitly state that the Exile is a "Wound in the Force," and not truly connected to it. Due to your connection to the Force being severed and your powers stripped, throughout your whole adventure, you siphon the Force energy from those you kill and your own party members (most of whom are Force-Sensitive and all of whom are in some sense bound to you) to stay alive, become stronger and use your Force powers.
 * In Quake IV, the main character eventually gains the ability to use a miracle healing fluid called Stroyent... which is created by using a bizarre cyborg monster to process liquefied human bodies. Indications in both this game and predecessor Quake II is that the humans are usually alive when they're liquefied -- fortunately, the liquefaction process, although gruesome, does seem to kill them.
 * It also shows up in Enemy Territory Quake Wars as a dual health/ammo pickup for the Strogg team, and destroying a processing plant for it is the GDF objective for one stage, but its origins aren't directly addressed in that game.
 * Though it is part of the advertising campaign for Quake Wars. In spite of its Soylent origins, the advert that features it is rather hilarious.
 * You also see dismembered humans powering certain devices around the Strogg factories, as well as one powering, and they are also alive and at times trying to escape. Most of them appear to be heavily drugged, a state in which they're probably better off.
 * Resident Evil: Survivor reveals that
 * Shin Megami Tensei: Digital Devil Saga, in a rather disturbing version. Your characters (and, by extension, your enemies, who have the same power) get stronger by eating other people. Which they do. With frequency and sometimes gusto.
 * Other demons, to be more exact. Killing humans actually gives you no Atma and you can't use Hunt skills on them either. It's definitely as per the above as far as the backstory is concerned, though.
 * In Star Control, the ships of the sinister Druuge can restore their energy meters faster by tossing members of their crew into the ship's furnace.
 * Their entire culture revolves around this. They consist of just one company, the Crimson Corporation, which owns everything. So any Druuge that transgresses is fired, which immediately leads to them being guilty of stealing Corporation resources (such as air), at which point they feed the furnaces. The creators of the game are quite proud of this little bit of nastiness.
 * In The Sims 2, a Cowplant's milk can grant the drinker an extra five days of life, at the price of one human life a pop. Sims can roll wants to "drink" their enemies.
 * Video Game Cruelty Potential if there has ever been any. If you want to be especially evil you can feed your entire neighbourhood to the Cowplant, making your own Sim immortal by eating the souls of children, so to speak.
 * In the doujin game Sora, Starbreaker has to tie herself to a satellite in order to attack the earth.
 * In Starflight, it is revealed that
 * Tales of Symphonia features Exspheres, a form of Magitek symbiote mass-produced by the villains that empower their wielders with superhuman abilities and can be used to power Magitek devices. The heroes must use them anyway, because the villains certainly won't stop doing it.
 * Tales of Symphonia features Exspheres, a form of Magitek symbiote mass-produced by the villains that empower their wielders with superhuman abilities and can be used to power Magitek devices. The heroes must use them anyway, because the villains certainly won't stop doing it.


 * Tales of Innocence has a line of giant war mechas called the Gigantess. These happen to be powered by the bodies of captured humans with magical powers like a literal battery.
 * The blastia in Tales of Vesperia are a widely used technology made partly from the souls of sentient monsters known as Entelexeia.
 * A bit of Wild Mass Guessing by The Sign Painter in World of Goo posits that the cute little sentient goo are the power source for the entire world.
 * Xenogears has a variation on this; the murderous pseudo-undead monsters known as Wels are revealed to be the byproducts of Solaris' human experimentation projects. At first, this causes the PCs to wonder if it's actually right to kill them... but then, it's further revealed that the reason they're murderous is that the experiments leave them in constant, maddening agony which they lash out with violence to try to relieve, and death is the only true escape left to them.
 * Also in Xenogears, the meat made in Soylent in Solaris is made of Wels.
 * In fact, the entire Soylent System -- a mechanism used to reabsorb mankind and Wels for their raw materials -- is a reference to the actual Soylent Green movie.
 * In Xenosaga, the nerve cells of Realians (who are basically "Bio-Androids" or human beings specifically made for certain tasks) are eaten as a drug. Arguably this is Squickier then if they were used for a food source. As least sustenance is a need.
 * Cecily and Cathe. Just...Cecily and Cathe.
 * Fable II features Reaver, who is as close to Complete Monster as is possible to get while being voiced by Stephen Fry. First, Second,
 * Try almost every enemy in Half-Life 2. There's a reason the Big Bads are known as the Combine (as in harvest). Combine mooks? Normal people with most people-bits taken out and cyborg alien science put in. The Headcrab zombies? Turns out the 'zombies' underneath the Headcrabs aren't all the way dead (and their screaming is some of the most potent nightmare fuel in the game). The Striders? Same thing as the "human" soldiers, but with another alien race. The same goes for their Dropships and Gunships, by the way. And who's in charge of assembling these things? The Stalkers. Humans with their limbs cut off and their vital organs removed, but kept alive and utterly dependent on obeying their orders. Walking is a privilege they have to earn, as are eyes. Without effort on the viewer's part, they're no longer recognisable as human. Alyx puts it best. "I hope you don't remember who you were."
 * In Galactic Civilizations there is a chance that any particular planet that is being colonized will have something special on it that lets the player choose from three options: Good, Neutral, and Evil. Many of the evil options (and some of the neutral options) are of the Forsaken Child variety. For example, a life form on the planet links people together to create a psychic network that gives a huge improvement to science production on the planet, but the people must permanently enter the life form's pods (signified by a reduction in population). The options are: (Good) Cordon off the area and allow NO ONE to enter.(Neutral) Hook up only the infirm and the elderly. (Evil) Excellent! Hook up a random selection of the population.
 * Yuri's household in Red Alert 2:Yuri's revenge would make even NOD shiver with unease. He got power from bio-generators (like in Matrix) that could be enhanced by placing additional humans in them. His primary harvesting facility was a Slave miner and the secondary one was a huge Grinder that processed humans into credits. He used cloning vats to churn out infantry and his super-weapon turned humans into bulky brute mutants. Oh, and all his army was mindcontrolled by him. What a jerk.
 * World of Warcraft's Scourge qualifies for horrible often enough, but the creation known as Thaddius fits this trope specifically, being made up of the souls and bodies of women and children slaughtered in conquering Lordaeron.
 * The Lich King's sword "Frostmourne" can absorb the souls of those it slays to power up, or to turn the slain into Scourge, controlled by the Lich King.
 * Its sister weapon, the player-obtainable axe "Shadowmourne" must absorb the souls of 1000 entities from Icecrown Citadel as part of its manufacturing process before it gains its full power. The visual effect of the buff it grants the wielder is a vortex of the absorbed souls swirling around the player.
 * And then, there's.
 * While by no means a required facet of gameplay, The Elder Scrolls series allows such behaviour. In Morrowind, soul gems can be used to eternally trap the souls of defeated monsters, and the resulting soul can then be used to fuel a magical weapon. However, Oblivion lets you take the same concept that little bit further, with the use of "black soul gems", a variant favoured by Necromancers that allows the trapping and fusing of human souls. In fact, human souls create the most powerful enchantments in the game. Not that every magical item could be eternaly fueled by an innocent animal's soul such as elks, foxes or even rabbits is any comfort.
 * The Shivering Isles takes this a step further with Dawnfang/Duskfang. To start with, it's a magical weapon and so must be recharged with soul gems. What's worse, it changes damage type with the day/night cycle (fire by day, frost by night), and each time it switches it can become (for the next 12 hours) a stronger version of itself... if the other form was "fed" 12 souls. So in order to keep the blade perpetually in its Superior state, one has to let it claim 24 souls EVERY DAY * and* make sure the enchantment itself is charged with souls. Add that to the rather disconcerting toothy maw of the blade, and one begins to wonder what sane hero would willingly carry this on her person.
 * You find it in the Shivering Isles, also known as the Realm of Madness. What did you expect?
 * In Skyrim, the Ebony Blade has turned into this as well. In the previous games, it was merely a particularly powerful Ebony Dai-Katana with some nice buffs. In Skyrim, it has a Life-Steal power that can be enhanced... by using it to kill people who love you. (In in-game terms, any NPC you've completed enough quests for to make them 'like' you.) In its base form, it's marginally useful. Fully-boosted - which requires you to murder 10 people who consider you a friend at the very least - it provides a powerful life-steal with infinite charges, making you extremely hard to kill in a melee.
 * In Metroid Prime 3: Corruption, you awaken after an unfortunate encounter with Dark Samus to find that your weapons, your suit and your body now run on Phazon.
 * Is this before or after Samus was saved by Metroid DNA in Metroid Fusion? Which, come to think of it, was created from research done on the last metroid hatchling from Metroid 2. Samus... is literally powered by a forsaken child?
 * The 'Prime' games are 'mid-quels', as it were. They take place after the first Metroid, but before Super Metroid.
 * All of Pathologic's healers' techniques involve this to some extent.
 * In Lost Kingdoms 2, it is strongly implied that the artificial Runestones  You only find this out if you go back and check  without meeting the requirements for the Good ending.
 * In the third Thief game (Deadly Shadows),
 * Mass Effect 2
 * As well as
 * Bio Ware also had this trope runnning in Jade Empire..
 * That's just an extension of the worst act.
 * Dragon Age has the golems, who
 * Also, a defeated blood mage will offer to magically increase your strength and endurance in return for his life,.
 * The trope is the force that drives the plot of all the F.E.A.R games.
 * The Soul Reaver in the Legacy of Kain series drains the souls of enemies in order to power itself up. However, the whole reason it can do this in the first place is that a maddened, ravenous spirit is trapped inside the blade...
 * The Angelic Rifle in Baroque fires bullets that contain
 * The Void Walker skill Breath Of The Dead Child from the now defunct Nexus War does Exactly What It Says On the Tin. in-game it's powered by magic points, but according to the fluff, the demon infiltrates the paediatric ward of hospitals, harvests the dying breaths of children, and unleashes them later, causing the children's tormented souls to bite and gnash at his foes. Hope you weren't planning to sleep tonight.
 * In Super Robot Wars, Jurgen's ODE System which was used to command the Bartolls which required living humans hooked up to cores. The Mironga, a variant merely has the pilot using the system linking them directly while maintaining some will of their own. The ATX and SRX team were shocked to learned about this, the fact that Lamia was used as the main nexus of the core prevented further victims from being used for the ODE System as the newer ones were totally unmanned
 * In Amnesia the Dark Descent,
 * Nearly everything in Blaz Blue is Powered By a Forsaken Child. The Magitek that the world is so heavily dependent on for its survival relies on seithr, The Corruption created by the Black Beast that made it necessary in the first place, . The Nox Nyctores that several characters use in battle
 * In Fatal Frame, the reward for the eight-year-old who wins a game of demon tag is to spend ten years locked in total isolation before being torn apart by ropes, all to keep the Hell Gate closed. The loser doesn't fare much better, having stakes stabbed into her eyes and becoming "it" for the next game of demon tag.
 * In Light and Dark the monsters you fight are fellow Guardians, people who decided to stand up against Darkside Raiders. But that goes against their nature, so the Gods in their infinite compassion blessed all Lightsiders so when they mentally degenerate into that which they fight, they physically degenerate as well. Oh, and half the player characters are Lightsiders, and no, they are not exempt. In fact the first main lead Caren learns a skill, "Love", to absorb the degeneration of others, but takes a burn back to her own.
 * In Chaos Legion,
 * The Garland device in Hellsinker is powered by four dead children buried beneath it.
 * Alice Madness Returns has the Dollmaker power the infernal train with the bodies of insane children, which reaches horror levels when you realise the very deliberate pedophilia subtext in that level.
 * In Deus Ex Human Revolution, the Hyron Project
 * And those system generated passwords? Hyron employees keep complaining in internal email how creepy they sound...
 * In the original Suikoden, the Rune that Governs Life and Death works like this - it's pretty powerful even at the worst of times, but it grows stronger by devouring the souls of people loved by the wielder. Friends, family, 's all good. He doesn't have to kill them directly, but nor does he get to choose - the Rune itself seems to employ some form of probability manipulation to bring about the death of the loved ones so it can grow stronger. On the bright side, it's literally the most fearsomely powerful Rune that has ever appeared in any of the games, so hey, at least you got something OUT of all those tragically dead family-members and close, long-time friends...
 * In Baten Kaitos Origins, Baelheit's machina is powered by . It's never made clear if the victims are still aware.
 * In Ico
 * In Alundra, it's no coincidence that you gain new items whenever someone dies:
 * In Ico
 * In Alundra, it's no coincidence that you gain new items whenever someone dies:

Webcomics
"Black Mage: "It takes the happiness of others and turns it into pain and explosions. It's win-win.""
 * 8-Bit Theater features a rather humorous example: Black Mage's Hadoken is powered by love. No, just sit there and I'll rephrase it. Every time BM launches a Hadoken, he siphons love from the Universe and twists it to highly destructive ends, making it create an explosion that consumes love (the divorce rate rises, for example). Not that he cares, but Red Mage seems to.
 * The Hadoken was also received by BM after sacrificing several orphans.
 * Of course, he would have sacrificed the orphans anyway. A hobby's a hobby.
 * Oh no, it would've been horrible if he had done it for no reason. That being his defense when White Mage loses all respect for him after hearing the above.


 * Kevin and Kell: In a World that lives by the Carnivore Confusion, this certainly doesn't seem out of place.
 * In Geist Panik, Nob says that human blood acts as a magic grease that all runes and magic use to some extent.
 * He also says that orphans' blood works best.
 * Heavily implied to be the source of the Black Rocs power in Necessary Monsters. You can almost hear the heartbeat over the motor...
 * In Sluggy Freelance, Torg's magical sword Chaz is powered by the blood of the innocent. He's only able to make much use of its full power when in a Sugar Bowl dimension being invaded by sadistic demons, so that there's plenty of such blood being spilled by others.
 * In Looking for Group,.
 * One of the themes for that chapter was that "Innocence is the cost of justice." This leads us to believe that
 * Richard's Nigh Invulnerability
 * The Alt Text for this strip of The Adventures of Dr. McNinja
 * In Terinu, the title character's entire race was genetically engineered to serve as living power plants for the Varn Dominion. And they were wired to enjoy it.
 * In Unity, a society full of sentient/uplifted animals, you might not want to know where their food comes from.
 * In Sinfest, the Devil promises the spray was laboratory tested on orphans.
 * In Homestuck, Her Imperious Condescension (the Troll Empress and the ancestor of Feferi) has a flagship that runs upon the immense psychic powers of The Ψiioniic, the Ancestor of Sollux--causing him excruciating agony. Also, trolls lower on the hemospectrum (like the Ψiioniic) live comparatively short lives, so the long-lived Condesce extended his lifespan with her magic. He's been her Helmsman for thousands of years.
 * In Spacetrawler, the construction of the eponymous spacetrawlers is implied to involve horrific abuse of Eebs, and when the details are eventually revealed, they're every bit as bad as implied:
 * Narbonic includes a time machine with the drawback that its use requires all the energy of the universe. Dave Davenport figures out how to use the time machine by having it comsume all the energy of a parallel universe. He assumes they just don't want to live as much as the people in his universe do.
 * Narbonic includes a time machine with the drawback that its use requires all the energy of the universe. Dave Davenport figures out how to use the time machine by having it comsume all the energy of a parallel universe. He assumes they just don't want to live as much as the people in his universe do.

Web Original

 * The in Lonely Girl 15.
 * In the short miniseries, Freako Asylum, the two protagonists go to "The Twisted Machine Of Science" to answer their questions on how to handle the situation. In its center is an infant hooked up to the machine. Unusually for this trope, the kid looks positively jolly and is dancing around in his/her seat.
 * Linkara's is powered by the soul of a little girl sacrificed by her parents to their evil god. That's where it gets... weird. To be clear, he only found out when the viewers did, and was as horrified as you'd expect.
 * This quote, taken from Llamas With Hats: "I should probably mention I filled our luggage with orphan meat." "Wh...what?" "Well, I'm building a meat dragon, and not just ANY meat will do!"
 * It turns out in the Whateley Universe that uber-powerful mage Fey's best spells are powered by energy from ley lines, and that in some of the battles already fought in earlier stories, she ended up destroying neighboring ecosystems.

Western Animation
"Ow! D'oh! After lunch, can I whip you?
 * In an episode of The Venture Brothers, Doctor Venture's family is trapped one by one inside his latest invention, a simulator known as the "joy can" that grants the user's fondest desires. One of its vital components was the heart of an orphan. Doctor Orpheus's disgusted response became the new Trope Namer.
 * In a different episode, Richard Impossible, patriarch of a Fantastic Four expy, averts Reed Richards Is Useless and uses his brother-in-law's pyrokinesis to power his tower. That same brother-in-law can feel his own flames, and Impossible gets called out/congratulated by one of the series' most effective villains for doing the most evil thing he'd ever seen.
 * Starscream's clone technology of Transformers Animated involves the use of protoforms, which can be described as fetal or pre-natal Cybertronians.
 * In Argai the Prophecy, Queen Dark gains and maintains her immortality by stealing the youth of several maiden throughout time and keeping them in eternal slumber.
 * Galaxy Rangers has the Psychocrypt. Literally sucks out Life Energy to create Slaverlords through which the Queen can see and hear. In this fashion, she can keep direct control over her armies and her crumbling Empire The Queen of the Crowns already hunted the Gherkin race to near-extinction in her thirst to create Slaverlords. Then, she discovers humans, who are ideal specimens to create Slaverlords. A good deal of the Rangers' job is to keep the Queen from obtaining more humans for the Crypt. The process, as seen in "New Frontier" & "Psychocrypt" is also horrendously painful.
 * The Marvelous Misadventures of Flapjack features a boat powered by angsty children. ... The children are also used as canonballs.
 * In Pinocchio,
 * Not all of them...some end up
 * A more mundane and light-hearted example found in The Simpsons: Homer is forced to turn a gigantic wheel, with a guy with a whip egging him on...in order to operate a rotating table at a party stocked with party food.

No.

Oh, no fair. Ow!"


 * Subverted in Mighty Orbots where Ohno, a robot shaped like a little girl, is the necessary ignition function for the Combining Mecha to operate. However, she doesn't mind at all since she's designed for it and once that function is complete, she disengages to become the Commander's copilot.

Other

 * One SCP Foundation short story involved "button day";
 * Actually, let's just say that a lot of the SCP Foundation's activities are this and save ourselves some time.
 * A bit of Fridge Horror for this one bur watch the Cap'n Crunch Commercials, to make the transition from live to cartoon via Crunitize they are turned into the cereal, does that mean the cereal is made of little children who couldn't survive Crunitizeing?

Real Life

 * The Aztec 52-year cycle. The gods needed human sacrifices to be strong enough to keep the world from collapsing and the sun to keep rising.
 * Research has proven that blood really does make good mortar. Specifically, it makes cement stronger and lighter. (United States Patent 4203674)
 * All Animals are fuelled by the death of other life. Be it actively killing and consuming it, or eating what grows in the decomposed remains.
 * In many parts of Africa, albinos are believed to contain magic power; and are often killed by witch doctors who believe that using their body parts in their magic can bring wealth and longevity. See this article from The Other Wiki.
 * In several regions of Africa, particularly southern Africa, it is commonly believed that having sex with a virgin will cure AIDS. As expected, rape of children is a huge problem, and the incidence of children infected with HIV is rapidly rising. (An additional problem: any baby born to an HIV-positive parent will carry the virus unless the mother is treated with expensive drugs.)
 * Europe had much the same problem after syphilis was introduced.
 * Chocolate, or to be more accurate, the cocoa industry. A whopping 42% of the 3,000,000 tonnes of cocoa that is produced each year is purchased from Ivory Coast, where everyday trafficked children as young as 12 years old (or sometimes younger) are forced into hard, hazardous work, usually without pay. They are often subject to physical and sexual abuse, denied education and medical care, and exposed to pesticides. Fortunately, there is chocolate available that is not made by slaves, such as Fair Trade Certified chocolate and organic chocolate.
 * Industrialized farming often has conditions that would spark public outrage if the same were done to cats and dogs. Animals often spend their entire lives crammed into the smallest space they manage to shove them in. Chickens have their beak partially cut off, because the bird's natural instincts is to peck at one another when overcrowded so they would spread out and give each other more room to breathe. Geese are force fed trough a tube to fatten them up. Even seafood is not immune, as farmed fish and shrimp are subject to the same kind of crowded conditions as poultry and livestock, and lobsters are often killed by being boiled alive.
 * Forced labor.
 * The bird trade. Most pet exotic birds were taken from the wild, for this reason (along with habitat destruction) many species of parrot (almost a third) are in danger of extinction. To make matters worse, the majority of birds die during capture and even more die afterward, which means that more are caught to compensate. Despite the high mortality rate, profits are still higher than breeding the birds in captivity, though captive-bred birds, while not having to undergo the traumatic capture and transportation, have their own issues. Regardless of where it came from, the end result is usually an unhappy bird cooped up in a cage most of its life.
 * Crab fishing is considered one of the most dangerous jobs in the world.
 * Many opponents of stem cell research cite this, as embryonic stem cells, the most versatile type of stem cell, can be harvested from undeveloped human embryos.