Cast from Hit Points - TV Tropes

"This spell allows me to use blood from my own body as a weapon. When struck, my enemies' blood would flow from their bodies to fill me with life. 'Tis a risk, yet the rewards are a temptation."

• In an early arc of Bastard!! (1988), Dark Schneider explains to the princess that casting magic requires a huge amount of focus and stamina. Dark Schneider, who is The Archmage and a borderline Physical God, is one of the only wizards who can cast multiple powerful spells in a day, and even he has his limits. This sets up the drama of the arc when he confronts the arc's villain, his former comrade the ninja swordsman Gara, while he's near his limit. As an early hint of his true power, Dark Schneider easily tanks Gara's strongest attack and unleashes a spell that brings down the entire fortress anyway.
• In Bleach, Coyote Starrk tears off pieces of his soul to form exploding wolves, leading to the erasure of half of his Fusion Dance who is more accurately half of his soul.
• In Brave10 S, Rokuro has replaced the lost Water Crest eye with the God's Jewel. Over time it becomes increasingly clear its magic comes at a physical cost, and as he is a Determinator, it's taken to dangerous levels in the final battle.
• Sakura in Cardcaptor Sakura is physically drained by the effort of converting a Clow Card into a Sakura Card. In Episode 53, when she learns that the Clow Cards will become ordinary cards unless they are converted, she attempts to convert eight of them^note  all in one sitting, nearly killing herself in the process.
• Cardfight!! Vanguard G: The ability of the Peacemakers to materialize units from Cray on Earth is quite the case of Blessed with Suck, as it requires imagination that "chips at your own life away". The side effects are various and horrific: one suffers from Rapid Aging and dies on-screen, another is almost paralyzed, and a third becomes an Empty Shell to cope with the pain. The others aren't that badly damaged, but one is in constant state of burn-out, and another is tricked into knocking himself in a coma via his own power. Notably, the reboot removes the cost of this ability.
• Destroy All Humans. They Can't Be Regenerated.: Hajime trades his Catastrophe for Emi's Hatred, a card that allows a player to convert their own life points directly into one of their monster's attack points for one turn.
• In the Dragon Ball franchise, the line between ordinary attacks, Cast from Hit Points, and Cast from Lifespan is blurry; characters use their ki to fire attacks, which is roughly analogous to their fighting power. To at least some extent, all ki attacks are also Cast from Stamina, but may have extra costs as well. Energy attacks can cause a huge exertion on the user's body, leaving them out of breath or weakened.
  • Tenshinhan's Kikoho (and Shin Kikoho) draws on his life force to attack with, something that inherently adds to an attack's potency, as shown by its effect on Cell in Dragon Ball Z. In a straight fight, Tenshinhan's power is nothing compared to Cell's, but by using his Kikoho, Tenshinhan is able to hold off Cell long enough for Android 18 to escape, but then collapses from the exertion. When the user is in good health the risks associated with it are minimal, but when Tenshinhan uses it on Nappa in a rage shortly after having his arm cut off, the strain is too great and he dies.
  • In Dragon Ball the Mafuba/Evil Containment Wave was initially stated to be so taxing as to kill the user without fail, and indeed both Mutaito and Roshi die after they use it. If it actually always kills the user is somewhat unclear: in the anime Tien uses it against Drum (having aimed for Piccolo) and survives^note . Both the anime and manga have Kami using the wave on Piccolo Jr., which he survives even though Piccolo reversed it on him; he even stated beforehand that it provided a way to stop Piccolo without killing him, which would also kill himself. Both of these suggest that a significantly strong body could survive without long-term consequence, there just wasn't anyone known to be strong enough before then. Dragon Ball Super proves that strong enough people can use the technique without too much worry with the health. Master Roshi, Piccolo, Goku and Trunks manage to learn and use it well without too much worry, which makes sense given their astronomic power.
  • Goku's Kamehameha also seems to draw on his energy reserves a lot, as shown in his fight with Perfect Cell; after blowing Cell to pieces with the attack, Goku's power level dropped dramatically. In fact, when the Kamehameha is used in the original Dragon Ball, Master Roshi flips out at the fact that Goku, Krillin and Yamcha all used it because of this. In fact, everyone panics at Krillin and Yamcha doing it because they shouldn't be able to handle it!
  • Goku's Kaioken is a pretty straight example. When used at low power and in short bursts, it can be used almost indefinitely. When used the way Goku does it, sometimes boosting its effect as high as 20 times normal, it inflicts a great deal of damage on the user. In fact, in Super it is explicitly stated that the strain of using the Kaioken is so great that attempting to use it while also transformed into a Super Saiyan would have been suicide. It's only the extremely precise ki control of Super Saiyan Blue allows Goku to even attempt to use the Kaioken while transformed, a move he estimates has a 90% chance of killing him. Even after the fight, the strain is so great he loses control of his ki entirely for a while.
  • Goku's transformation into a Super Saiyan 3 also serves to do this; the physical strain on his body of maintaining the state and using energy attacks whilst in it is enough to drain him of all his energy in a very short time.
  • Vegeta also did this against Buu, sacrificing himself, but it wasn't enough. He uses the same technique in Dragon Ball Super to defeat Toppo in the Tournament of Power and has better luck there.
  • In the Dragon Ball Super manga, we have Vegeta's Ultra Ego form. Similar to Goku's Ultra Instinct, it gives him greater power the more he's injured, but if he's too injured, he won't be able to use it at all.
• In Fushigi Yuugi, Mitsukake can only use his Healing Hands once a day because of this. When he overdoes it towards the end, he dies.
• Infinite Stratos does a technological example of this. IS battles end when one side's energy shields are depleted in order to avoid injury to the pilot — in fact, the unshielded IS instantly shuts down to prevent further fighting. The protagonist's most effective (and for a long while, only) attack is Reiryaku Byakuya, which saps his own shields to pierce through the enemy's and score an instant kill. The first time he used it, he had no idea how it worked and therefore lost the match because his shield zeroed out less than a second before the attack connected. After learning about it, he's understandably reluctant to use it against a manned IS ever again.
• In Inuyasha and Yashahime: Princess Half-Demon both the titular Inuyasha and his Daughter Moroha can use a technique called Blades Of Blood where they coat their claws in their own blood and then launch it at foes. As this is more of a panic button kind of attack, they'll usually save it until they've already been wounded though on more than one occasion Inuyasha has injured himself willingly to be able to use the attack. Typically during moments when he doesn't have the Tessaiga and Iron Reaver Soul Stealer is lacking in either power or range.
• Lyrical Nanoha gives one of these to Nanoha in the third season. It's called the Blaster System and it boosts Nanoha's power and gives her a set of Attack Drones that can cast her spells independently of her, for a potential boost of better than 4x her already monstrous power level. The cost of this is placing an immense strain on Nanoha's body and dealing physical damage to herself and to Raising Heart; when she used Blaster 3 in the climax of the third season, she lost 8% of her total magical power and had to spend the next few years on enforced vacation to recover it.
• In Magi: The Labyrinth of Magic, using too much of your magoi is dangerous because of this. Magi, who can use the magoi and rukh outside of their bodies, aren't too bothered by this.
• In Mahoromatic, Mahoro's most powerful weapon (usually manifesting as a plasma-like flame on her fist) is directly powered by her life force. Since her energy is running low to begin with, using it shortens her remaining lifespan dramatically. Mercilessly made explicit by the "Days until Mahoro stops functioning" counter that is shown after every episode. There will always be a significant drop in numbers whenever she uses it.
• This is how the original Shuffle Alliance defeat Devil Gundam Form II in Mobile Fighter G Gundam, at the cost of their own lives. The main characters later learn the same technique, but manage to pull it off without dying, possibly by virtue of being much younger and healthier than their aging predecessors.
• In Mobile Suit Gundam: The Witch from Mercury, this is how Gundams work by default, as an Internal Deconstruction. Being linked to such a heavy, high-tech piece of machinery subjects the pilot to immense physical and psychological strain and, if they're not careful, leaves them susceptible to "data storms" that burn them out entirely. The prologue ends with Delling Rembran using this knowledge to forcibly shut the project down and kill almost everyone involved - Nadim Samaya manages to fend Cathedra off long enough for his wife and daughter to escape, but the strain kills him.
  • A significant plot point is the fact that protagonist Suletta Mercury (the titular "Witch from Mercury") is able to avert the trope and pilot Aerial without this happening. It turns out that Aerial is Powered by a Forsaken Child who helps to take the strain. When Suletta's forced to pilot a different Gundam during the final battle, the strain almost cripples her.
• My Hero Academia:
  • The First-Episode Twist (in the second episode) is that All Might suffered a major injury a few years back, and since his Quirk "One for All" causes a huge strain on his body, he can only stay in his super form for a few hours at a time, during which he'll randomly start coughing up blood. Fortunately, he can pass his power onto somebody healthier, and chooses protagonist Izuku for the role. Even after passing on his power, All Might retains a remnant of it that allows him to keep being a superhero, but the strain gets even worse. Whenever he exceeds his time limit, he ends up with an even shorter time limit going forward. Naturally, All Might keeps getting forced to exceed his time limit to defeat powerful villains. To defeat his nemesis All For One, All Might burns out essentially all of his remaining power and can now only change into his super form for one second. This forces him to retire from heroics permanently, depriving the world of its "Symbol of Hope".
  • Izuku himself is another example, since unlike All Might, his body is too weak to use One for All's full power without him breaking his limbs, so he often finds himself forced to use it sparingly, usually with a few fingers as opposed to his whole arm, until he becomes strong enough to master it properly. He too is repeatedly forced to exceed his limits to defeat powerful foes, resulting in him spending a lot of time in hospital beds recovering from self-inflicted injuries.
  • Recovery Girl's powers also work like this, except that it takes the hit points of those whom she's healing, not herself. Her power just speeds up the body's natural recovery, so you need to have a certain amount of energy before she does it or her "healing" could prove fatal.
  • During the final battle, All For One himself unleashes the ability to overcharge his own powers, making them much more destructive at the cost of severely damaging his own body. Except that he also has the ability to regenerate from the damage he takes, so it's just a minor hindrance. Then it turns out that, since his regeneration is generated by an imperfect copy of the Rewind Quirk, it comes at the cost of making him younger, meaning that he's trading off Hit Points with Lifespan.
• In Naruto, jutsu require chakra and stamina to be used. In most cases, ninja get to the point where they're unable to use jutsu when they're low on chakra, but if they run out, they die.
  • Rock Lee's Eight Gates are a straighter example of this. The more he opens, the more powerful he becomes, but the greater the strain it puts on his body. It's stated that if anyone opens all eight gates (known as Hachimon Tonkō no Jin, or Eight Gates Released Formation (Eight Inner Gates Formation in the dub)), he or she will die, which is why the eighth and final gate is called Shimon — the Gate of Death. In Lee's case, his muscles actually ripped when he opened the fourth gate, appropriately named Shōmon — the Gate of Pain.
  • How powerful can a ninja be when all Eight Gates are open? Powerful enough to be able to curbstomp a Physical God. Demonstrated when Guy performed this technique and went to wipe the floor with Madara, who at that time was the Ten-Tails host and was previously curb-stomping the most powerful ninjas in the world. Guy even gets complimented by Madara for being the first one to actually give him a challenge, but points out that it would only be a matter of time before Guy's technique ends and all Madara has to do is wait it out since it didn't (or couldn't, anyway) kill him. Madara was using Perfect Susano'o, said to be impenetrable. Guy's final attack shattered it and blew away most of Madara's chest and torso, although thanks to the Ten Tails' near-inexhaustible chakra and Healing Factor, Madara survived. Said technique was mastered by Might Dai, Guy's own father. How strong was he with it? Enough to where he was able to go toe-to-toe with all Seven Swordsmen of the Mist at the same time in order to save his son and his comrades. While the battle did take his life, he manages to kill four of the Swordsmen and left the other three severely beaten.
  • Choji Akumichi's "Butterfly Mode", at least when it's introduced, is in the form of a pill that rapidly burns off all of the body's fat and muscle. As Choji was, it was entirely likely that it would kill him, he only survives because he was just fat enough that he still had enough nutrients to keep him alive until he could get medical aid. In Shippuden, Choji shows during the war arc that he's become able to use butterfly mode to no adverse effects, though it still slims him down (presumably because he can manifest it through his own chakra, instead of requiring the pill.)
• Natsume's Book of Friends — Whenever Natsume frees a Youkai from his late grandmother's (and his own) servitude, it has a physically draining effect.
• One Piece:
  • While it's not strictly magic, there's the Impact Dial, which can absorb and fire any physical force. However, the recoil is exactly the same force as the actual impact, meaning that whoever uses it takes as much damage as they deal with it. The improved version, the Reject Dial, actually increases the power of the impact, but it's said that using it twice will cause the user to die. After being told this, Wiper then proceeded to use it three times and survived.
  • Luffy's Gear Second leaves him thoroughly exhausted after use, as it speeds up his blood flow to increase his power, which also speeds up how fast his body absorbs and processes nutrients. Lucci even pointed out that there was a danger of dramatically reducing his lifespan by using it. Training during the Time Skip mainly fixes this problem.
  • Trafalgar Law is unusual, if not unique, in the One Piece world in that his Devil Fruit power, the Op-Op Fruit, actually drains his stamina where nearly every other Devil Fruit user is able to spam their powers with impunity. In fact, to use his Fruit's most powerful ability, which makes an individual completely immortal, the cost is, without fail, the user's life.
• The Caster's three most powerful shells in Outlaw Star, #4, #9 and #13, work at the cost of the user's life force. Firing two will leave the user winded, and a third will bring them near death. "Just like, you know..." Gene fires four in a short period of time.
• In Penguindrum, Momoka Oginome claims to be able to do this. She says that she can change the fate of living beings via her Destiny Diary, but adds that she'll have to pay a price: suffering bodily harm in exchange for what she wants to do/fix/etc.. To save a bunny from dying, she cast a "fate changing spell" in the Diary and got a cut on her hand in exchange; later, to rescue her friend Yuri from her abusive father, she cast another one and got severe burns that landed her in the hospital. In fact, when Yuri tried to touch the Destiny Diary, Momoka stopped her from doing so to avoid a possible backlash from hitting her.
• In Pokémon Adventures, though it's never explicitly stated, it's safe to assume Yellow's powers fall on the mild side of this trope as overusing her powers runs the risk of exhausting her and putting her into a deep sleep.
• In the manga version of Prétear, the Leafe Knights' Elemental Powers are connected to their own Leafe (Life Energy); overusing these powers drains their Leafe, regardless whether the attacks are performed by the Knights themselves or by Himeno when she merges with them. In the backstory, three of them died from overusing their powers in order to seal Takako, and were reborn; Shin, the youngest of them, dies for the second time after Himeno merges with him. In the anime, to seal the Tree of Despair, Himeno overloads it with her own Leafe and dies in the process. Only Hayate's True Love's Kiss can bring her back.
• Rebuild World: Much of the enhanced performance Akira gets from his Virtual Sidekick Alpha using his Powered Armor like People Puppets is like this, because torn muscles and broken bones naturally result from Akira’s enhanced strength armor moving without him and being pushed past its safety parameters. This causes Akira to take Healing Potion before fights rather than waiting to get injured (which works because those are based on Nanomachines). For example, at one point Akira leaps In a Single Bound, but has to get new legs grown and transplanted onto him at the hospital after from the damage that caused.
• Sailor Moon:
  • Usagi's Silver Crystal worked this way for dramatic tension; it's explicitly commented on in two movies, specifically her (temporary) death after using it while already exhausted in the first movie. It is also heavily implied in the backstory Queen Serenity died from strain of using it. In the anime, Usagi's ability to have the senshi safely boost her power may explain why its use decreases later in the series.
  • While the manga version seems more powerful and less dangerous to use, late in the manga, Sailor Moon's (temporarily) entire body disintegrated completely from its use. Then again she was technically using all the Sailor Crystals to defeat Chaos.
  • Played with in Pretty Guardian Sailor Moon, where the audience assumes this rule for why Usagi shouldn't use her crystal. We later find out the object is dangerously neutral in regards to reacting to Usagi's emotions, and Beryl rightfully points out Sailor Moon could end up killing everyone else.
• Chi manipulation in Saiyuki apparently works this way, at least in defensive uses. Hakkai exhausts himself to the point of fainting when he has to heal Gojyo after not having enough sleep, and it's mentioned outright that trying to do this when injured can kill him. He also gets weak after holding up a chi barrier for too long, trying to save the party from being buried alive in an underground room.
• 3×3 Eyes has the Juuma (Beast Demons, sometimes localized as "Fighting Larvae") magic developed by Benares: Juuma are born in eggs, which hatch when blood is spilt on them. The user then must tame the Juuma and form a contract with it which lets him summon the Juuma whenever he wants. However, each usage taps into the Life Energy of the wielder, and a normal human would exhaust his forces and die quickly. However, Wu such as Benares and Yakumo are completely immortal and thus can make full use of their Juuma. The sole human Juuma-user, Sarlama, had to replace her own limbs with them and her entire abdomen is completely dried up and horrifying to look at. The same, to a lesser extent, goes from all the magical arts, which according to Connery are fueled by life force.
• Sekai Oni: How the Alices' avatars work with every single action in Wonderland. A base of 1000 points, variable actions are usually small but big expenditures with manifesting items and weapons can take upwards to 100 or more potentially, and they regenerate one point a second. Manifestation instead works as an ongoing drain on this energy supply for great power. Killing a World Devil, however, expends all of your energy at once — and the Chesire Devil keeps the Alice alive by calling on a "reserve tank", killing someone close to the Alice as a result.
• Shakugan no Shana has this in Yuji. As a Torch, he's technically already dead, and, under ordinary circumstances, would inevitably be doomed to burn out and fade from existence. However, he's also a Mystes, and happens to have the artifact Reiji Maigo sealed within him, which replenishes his power of existence every midnight. As such, as long as he doesn't use up all of his existence in a day, he can lend his power to Shana, and, later, cast his own unrestricted spells, using his very existence.
• Some spells in Slayers can be so powerful that they draw upon the user's life force when cast — the best example is the Incomplete Giga Slave, which temporarily bleaches Lina Inverse's hair white after she casts it. The novels explicitly state that one of the defining attributes of a spellcaster is a high amount of stamina, as casting spells physically drains a person. When the setting was adapted as a Role-Playing Game, firstly under the Big Eyes, Small Mouth umbrella and then under the D20 umbrella, casting spells would cost health. In the RPG, it normally costs nonlethal hit points (fatigue), but taking lethal drain is also an option.
• Symphogear has the Superb Song. Using this skill allows the user to unleash the full power of their Symphogear, but at the cost of intense backlash damage onto their own body, which can even be fatal.
• Toriko's Autophagy. If he runs out of energy and needs more, his Gourmet Cells "eat" his own body to gain more power. If the Autophagy goes unchecked, Toriko's body will eat itself to death.
• Yu-Gi-Oh!:
  • In the game of Monster World, Bakura (a white magician) converted his hit points to magic points to keep up a magic barrier when Zorc was blasting them. This is also the main rule in the Ancient Egyptian precursor to the Magic & Wizards/Duel Monsters game; Monster Spirits are summoned by sacrificing Ba (life force) instead of the modern life points system. Damage is also taken by decreasing the life force of the duelist, implying that a defeated duelist dies.
  • Dark Bakura's second tabletop RPG employs this for all the character cards. When a character uses his/her Ba to empower/summon a Monster Spirit or gets damaged, it decreases their Hit Points.
• In Yu-Gi-Oh!: Capsule Monsters, the first times he uses the Duel Armor, Yami collapses, or is at least left drained.
• YuYu Hakusho:
  • Yusuke Urameshi funnels his life energy into a last-ditch assault on at least one occasion, in the final phases of his fight with Suzaku of the Four Saint Beasts. The strain leaves him unconscious and on the verge of (another) death, and it takes Kuwabara channeling some of his own life energy into him to save him.
  • Kuwabara's energy blade is directly provided by his spirit energy, so when he runs out of it he'll remain vulnerable until a rest (as shown after his fight against Byakko). It's notably less costly with the ultimate form of the blade (Dimensional Sword), likely to make up for the great difficulty of pulling it off in the first place.
  • Kurama attempts a Heroic Sacrifice during the Dark Tournament using this trope. When he (just barely) survives, he discovers the magic fruit he's been using to temporarily become Yoko Kurama has been wearing off faster because Yoko Kurama's power is bleeding into his own.
  • While first using it caused severe burns on the arm he cast the attack with, Hiei's merging with the Dragon of the Darkness Flame causes him to pass out for several days.

• In Lycee TCG, since the orthodox way to lose the game is having no cards in your deck when you're supposed to draw one, your deck effectively acts as your HP. The more powerful Standard Abilities usually requires you to discard cards directly from your deck.
• Magic: The Gathering has plenty of cards and effects that have a cost in health.
  • Necropotence is the card that truly emphasizes the usefulness of this trope; when it was released, its use dominated tournament play. Remember, tropers: the only truly important hit point you have is the last one.
  • Similarly, Channel is a direct-example of this trope, allowing you to trade life for mana. It was a vital part of the Channel/Fireball combo, one of the first known First Turn victory hands.
  • The New Phyrexia set introduces "Phyrexian mana" (the symbol for which looks a bit like phi ɸ), which can be paid with either one mana of the appropriate colour or 2 life.
  • For an example not derived from the player's life, Devoted Druid weakens itself to provide more Mana for you to cast with. Without outside help, this only works once before it would die from lack of toughness.
  • There's also Greed, which lets you draw one card each per Black Mana and 2 Life you pay, and the Game-Breaker Yawgmoth's Bargain. There are no words to adequately describe just how broken a "Pay X Life: Draw X cards." effect is. In fact, the card may as well have said "Pay 19 life: Draw 19 cards."
• In the under-advertised game Magi-Nation, ALL spells and abilities were cast from hitpoints. There was no MP or Mana to speak of, so monsters and your own character would use the same life force to cast magic with that they'd use to absorb damage from the enemy. Additionally, summoning your Mons cost the protagonist life energy equal to the beastie's hitpoints — in the video game its remaining HP would be refunded to the hero at the end of the battle. All this combined made for an interesting level of strategy wherein you would have to decide whether the loss of life was worth being able to kill the enemy that much faster (and also made heal spells rather dubious in their usefulness — the amount healed is almost always lower than what it costs to cast in the first place).
• Shadow Era also has several cards that can damage the user. Some items (such as Rusty Sword) damage the user when destroyed, while others can constantly drain from your health for some benefit (like Enraged which allows the player to draw an extra card at the cost of one health a turn).
• Yu-Gi-Oh!:
• In Slay The Spire, both the the Video Game and Board Game, the card for the Ironclad character called Hemokinesis deals 15 damage at the cost of 2 hp. For reference, the standard strike card has 6 damage.

[/folder]]

[[folder:Comic Books]]

• Batman and Robin (2011): The Hellbat suit draws from Batman’s metabolism. In Luthor’s words, using it too much could result in the wearer being drained dry.
• Doctor Strange: In Jason Aaron's 2015 run, this is how the kind of magic that Doctor Strange uses works (and it's implied that's how all magic works now). Just as punching someone can hurt your hand, sorcerous attacks can badly mess up the sorcerer inside. It turns out that this damage can be transferred to others and Wong has been training an order of monks to do exactly this, without telling Steven.
• Gold Digger (Antarctic Press): The Renewing Breath technique is a wonderful and terrible variation: It requires a sacrifice to heal the mortally-wounded, but rather than cast from the life of the user, it takes the life of the one who taught the technique to the user.
• The Mighty Thor: Thor's most powerful attack, the God Blast, channels his life energy through Mjolnir, combining their power for an attack that can drive away a hungry Galactus.
• Ms. Marvel (2014):
  • Kamala's powers, or at least her Healing Factor, come straight from her life force, so overusing them (like healing a potentially lethal wound and going on a rescue mission not long afterwards) leaves her ravenously hungry and so tired as if she skipped sleeping for days. When she embiggened her fists in a fight while already been mortally wounded, the strain of both (which was already preventing her from transforming her appearance into that of someone else) "pretty much uses up the very last little bit of my strength. I can't heal fast enough to get ahead of it. Whatever fuel my healing factor uses up is gone."

  Kamala: I'm hungry in a way I've never been hungry before. Ravenous. Starving. Seriously, I need a thesaurus. It's the healing I think, it feels like I skipped a night of sleep — like the healing power comes straight out of my life force.

  • The Magnificent Ms. Marvel: The Stormranger suit powers itself by converting portions of its own mass into energy. It does so extremely efficiently, meaning that it only needs to consume tiny bits of itself at once, but using a lot of energy — such as to fuel powerful attacks — will eventually corrode and consume its body. Kamala uses this to give the being an existential crisis during their second confrontation.
• Sonic the Hedgehog (Archie Comics): Bunnie Rabbot is a Cyborg whose legs, lower-torso and left arm are completely robotic as a result of being put halfway through Dr Robotnik's roboticization process before being rescued by Sonic and Rotor. Her robot limbs and the powers they have are fully operational, but it all runs on her organic lifeforce due to lacking a traditional power supply. Using her robot abilities too much puts her life in danger as a result.
• Tzu Kai uses this near the end of Xanadu: Across Diamond Seas after exhausting his more conventional magical abilities.

• Both Godzilla and Spacegodzilla in The Bridge seem to be able to unleash most of their special attacks from an energy pool. Once that is expended however, they can resort to this trope to keep fighting; albeit at a cost. After dueling for hours they expended so much power that their last strike nearly killed both of them.
• Dungeon Keeper Ami uses her Keeper powers to punch the Horned Reaper so hard that she pulps her own hand and wrist. It takes time to recover, even with magical healing, but it's effective.
• In Fallout: Equestria - Project Horizons, Trottenheimer's Folly is a massive single shot pistol that fires special bullets of unknown origin that can tear through everything: armored battleships, unbreakable magic shields, etc. However, firing it causes the shooter to be flooded with a massive burst of radiation. Firing it twice within the span of a week was deadly enough to kill Blackjack.
• In the Sword Art Online fanfic, Fairy Dance of Death, modifying a magic spell with nibralth lowers the required skill level and splits the cost equally to the caster's HP and MP.[1] It's the only way Sasha can cast the spell needed to break the defenses of the 25th gateway boss, «Hrungnir the Impervious», leaving her with only a small fraction of health... and the undivided attention of a boss many levels higher than she is.
• The True Patronus charm in Harry Potter and the Methods of Rationality. Innocence illustrates the deadly consequences of putting all of your life into the charm.

  Part of Harry's life flowed back into him.
  Part had been lost as radiation.
  ...the magic flowed obediently out of him and helped Bellatrix to her feet. (For it wasn't his magic he had expended, it had never been his magic that fueled the Patronus Charm.)

• Laserllama:
  • At 10th level, Psions become able to cast their spells using their health instead of their Psi Points.
  • Bloodknife Rogues can expend hit dice to empower their Sneak Attacks.
  • The signature feature of Vampiric Soul Sorcerers is that they can sacrifice their hit points to cast spells instead of using spell slots.
  • Witch Knight Fighters can expend hit dice to deal extra necrotic damage when attacking.
• sun's up, another day goes by: Physical skills take a HP cost in the canon game, which has been translated into physical skills physically harming the user here — Bloody Charge is described as collapsing the user's ribs in and both Shinjiro and Makoto spit blood after using it in i caught fire and dies irae respectively. Overuse of magic skills also hurts the user: Yukari nearly suffers a Heroic RRoD in kissing you goodbye with her heart stopping for several seconds while trying to keep Shinjiro alive.
• In the Twilight Storm fic "The Perils of Lorindar", when Snow White summons the seven dwarves- magical spirits that she can only summon at the cost of seven years of her life- the Doctor is able to transfer some of his life energy to Snow so that she can summon the dwarves without losing any years herself.
• Voyages of the Wild Sea Horse: Nabiki Tendo's Bat-Bat Fruit, Model Type: Vampire Devil Fruit has haemokinetic abilities that sit somewhere between here and Elemental Baggage. Whilst Nabiki is able to store gallons of blood in Hammerspace, she still has to replace that by drinking it from people or animals; once her reserves get low, she'll start tapping into her own personal blood supply, and if she uses too much of that, she'll end up temporarily stuck in a chibi version of her werebat form.
• In the old crossover story What Insertion?, this is the primary downside of Sunburst's Furnace move. It acts as an internal Sunny Day, greatly enhancing the Flareon's Fire-type moves, allowing it to use Flame Wheel, lessening the damage from Water-type moves, and enveloping the battlefield in a heat wave. However, Sunburst's internal temperatures rise to the point where they're too much for him to take, steadily sapping at his energy the entire time until he either fully expels the excess heat or his opponent does it for him.

• Avengers: Infinity War:
  • Thanos uses the completed Infinity Gauntlet to erase half the universal population, with the snap of his fingers. While he only got off with some severe burns from it, Avengers: Endgame shows what happens when a regular human being uses the Gauntlet, with Tony Stark snapping his fingers with the Stones to erase Thanos and his army, but the injuries he sustains end up being fatal, and he dies shortly after, a risk he was willing to take.
  • Prior to Tony's sacrifice, Bruce Banner — now apparently permanently transformed into the Hulk — was able to use the Gauntlet to restore those killed by Thanos's Snap, but it left his right arm seriously burned in a similar manner to Thanos's injuries.
• In Eragon, magic is very rarely used because it drains the caster. Indeed, the main character almost dies by using magic. Specifically, spells use the same amount of energy that the caster would have to expend to perform the same task without magic. Using a spell to, say, lift a penny off the the floor right in front of you would be almost effortless. If you were to use the same spell to levitate the same penny from a mile away, it would take the same amount of effort that it would've taken you to walk all the way over to it.
• In Pokémon Detective Pikachu, much like the video games the film is based on ^note  Volt Tackle is a very powerful move, but it damages the user by a lot. When Tim suggests Pikachu use Volt Tackle on Charizard in the underground battle ring, he refuses. During the climax, Pikachu hits a possessed Mewtwo with a Volt Tackle hard enough to send the latter crashing into a building, nearly knocking Pikachu out, too.
• Star Wars:
  • In Revenge of the Sith, Darth Sidious does this during his battle with Mace Windu. Windu has him cornered and disarmed, as Anakin rushes in. Sidious attempts to seize on the distraction and electrocute Windu with Force Lightning. In order to overpower Windu's block, he even uses energy from his life force. But when Windu reflects the bolts of lightning back at him, the sapping from his life force intensifies until the grandfatherly-looking elder is left looking like a withered old man.
  • The Force Awakens: During the battle on Starkiller Base, Kylo Ren has been shot by a bowcaster. Several times during the fight, he pounds on the injury, generating more pain which he can use to fuel the dark side of the Force.
  • The Last Jedi: When a Force link causes Kylo Ren and Rey to see each other from halfway across the galaxy, Kylo claims that anyone using Astral Projection across such a distance should die from the strain. This foreshadows Luke Skywalker's Dying Moment of Awesome, in which he uses the Force to confront Kylo on Crait and buy the Resistance survivors time to escape.
  • The Rise of Skywalker: Rey learned how to use the Force for Healing Hands, but mentions using it drains the user's health. At the end, Ben Solo heals a mortally wounded Rey while heavily injured himself. He saves her, but dies in the process.

• In Zaltec II: The Generation Stone, the only way to gain magic points is to permanently sacrifice health points.

• In Aetheral Space, Aether burning is a technique that dramatically amplifies the user's strength but tears their body apart with the strain. It's possible to survive a brief burn, but a few minutes is enough to kill the user, limiting its utility outside of Taking You with Me strategies and emergencies.
• In The Bartimaeus Trilogy, the most vital part to a Golem's functioning is a magical scroll inserted into the construct's mouth. The writing of said scroll drains the vitality out of the writer to be transferred into the golem, and writing more than one manuscript (at least in a short time) is likely to kill you. (Though since golems completely neutralize all demon magic in their vicinity and all of magicians' power is based on demon magic, one is often enough.)
• I Became the Villain the Hero Is Obsessed With: Super Villain Protagonist Da-in can use Mind over Matter and Psychic Teleportation powers, but if he goes too far using them, especially teleporting long distance, a Blood from the Mouth and/or a Heroic RRoD follows.
• All spells in The Black Magician Trilogy reduce the caster's Life Energy unless said caster is a Black Magician, who may use others' Hit Points instead.
• In the Chaos Gods series, Ki normally uses magic provided by her god, Tavk. If Tavk chooses to withhold his power from her, she can cast spells using her own energy; but doing so consumes her own flesh as fuel.
• Chosen One Protective Services: If you don't have enough chakra to fuel your spell, it will instead draw upon your life force, causing damage, sometimes permanent, to your body. It also results in any passive upkeep spells going down, which is often fatal because they're the primary form of defense.
• The Chronicles of Dorsa: Sorcerers' spells drain them of energy. After creating the illusionary army for Tasia, Evrart and his fellow Brothers of Culo are exhausted. He estimates it will be three days until another feat like that could be performed.
• Cradle Series: The Madra Engine is a divine treasure that converts the life and blood of the user into madra for them to use. If an Underlord (some of the most powerful people in the world) tried to use it, it would burn them up in ten years if they're lucky. Oh, and it's made from pure madra remnants, which only come from humans who haven't practiced a Path yet, meaning you have to kill at least a few dozen children to make it. Those with stronger bodies can use it safely; dragons often do so, and the dragon Monarch gives one to Yerin as a cruel "prize" that she can't actually use. But then someone else gives her the greatest Life elixir in the world as their prize, allowing Yerin to use it safely after all.
• In The Dawnhounds, weaving requires life energy going in to put magic out. That energy can come from an external source, but in a pinch can come from the weaver themselves. It has a tendency to go poorly.
• The magic in Katherine Kurtz's Deryni series works this way; using Deryni powers requires concentration and is physically fatiguing. The more powerful the working, the more exhausting it is, and repeated and/or extensive use of the powers in a short timeframe can cause a Deryni to black out.
• Sorta in Discworld. For a Wizard to do something, it takes as much energy to do something magically as it does physically, unless you can harness an outside force. Having no outside force makes the Wizard rely on the leverage of his mind, meaning if they try to do something too difficult, their brain flicks out their ears. Example: Galder Weatherwax makes a protrusion of stone on the University fall, allowing him to zoom upwards.
• In Doctrine of Labyrinths, mending the Virtu leaves Felix unconscious for two days, and he slits one of his wrists in order to lay to rest the ghost of Magnus Cordelius.
• While after the first book of the Dragonlance series, magic functions by drawing power from the Moon Gods, before they are unsealed all magic is used with the caster's own energy, as shown whenever Raistlin uses too many consecutive spells and is left exhausted.
• Dragonvarld: Marcus learns the more powerful spells take energy from him enough to cause exhaustion after he uses several while fighting.
• In The Dresden Files:
  • Magic spells can be cast from any energy available. The human body itself contains substantial energy; a magic user can use that to power spells but obviously won't still have any afterwards to run their body- this is used when dying to power a magic user's 'death curse'.
  • There's Soulfire, which allows a caster to infuse some of their own soul into their spells to boost the power and effect of the spell. Unlike Hellfire, however, Soulfire isn't destructive, but rather constructive. Harry ends up using Soulfire to generate a powerful hand-like construct of force to beat the hell out of a Denarian spellcaster. The drawback behind using Soulfire, of course, is that it uses your soul as the fuel to empower your spells. Partially drained souls in The Dresden Files universe do regenerate, and pretty quickly if you do soul-affirming things — but as Bob explains it very succinctly, if you subtract five from five...
  • Also, for ghosts, any form of attack besides Good Old Fisticuffs is one of these. Ghost's attacks and their lifeforce, for lack of a better term, run on memories. One needs a particularly powerful memory that is important to the ghost to be able to do serious harm to other ghosts. Those who lose their memories devolve into hungry monster who crave the memories of other ghosts.
• In Everworld, magic-users are shown to weaken if they use too much power, leading Jalil to wonder if magic burns calories. Merlin, for example, is so tired after his battle with Loki that it's months before he is able to fully recover.
• Some of the Fighting Fantasy books, especially the aptly named Sorcery! four-parter, have EVERY spell being cast at a cost of health.
• In Stephen King's Firestarter, Charlie's father gets progressively worse physical damage from using his mental powers, from headaches to a ruptured vessel in one eye to a full-on stroke.
• The Forgotten Realms novels see this a couple of times with mythals.
  • In Elminster in Myth Drannor, Cormanthor's greatest elven high mage sacrifices his life to create the city's mythal, his life's work.
  • At the end of Return Of The Archwizards: The Sorcerer, set several hundred years later, another high mage sings himself into the mythal over Evereska to help repair it after the damage done to it by the phaerimm siege.
• Genocide Online: "Oath" boosts player's stats significantly, but it also drains your HP every second, so it must be used wisely.
• Discussed in A Grimm Quest with a technique called "pulling from the fade". Ash specifically says that the Fade is not his life force; while Amy describes that pulling from it still has the potential of killing the user or sending them into a coma.
• Mages in Mercedes Lackey's Heralds of Valdemar series can do this; the eventual result is known as "drain shock", which is usually fatal. Alternatively, a mage can simply burn themselves out like a candle to perform a "final strike", the idea being that if you have to die, by god you're going to take someone out with you. Perhaps unsurprisingly, more than one protagonist mage uses the Final Strike to achieve a Dying Moment of Awesome. If the Shin'a'in get absolutely desperate, one of their Shamans or Swordsworn may be called upon to make the ultimate sacrifice in order to invoke divine intervention. It's implied that the same rules also apply for those with particularly powerful versions of the Gifts that also operate in the series. The power Lavan Firestorm unleashed is uncannily similar to a mage's Final Strike and the results equally cataclysmic.
• In the Inheritance Cycle, magic is cast by expending the caster's physical energy. It takes as much energy to do something magically as it would to do something physically. In addition, once an incantation has been uttered, the caster must commit to the spell, even if it kills them. Knowing your limits is very important for a spellcaster in this universe. Dragon riders have an advantage: a rider can borrow his dragon's hit points to cast spells. Dragons, needless to say, have lots. As of book 2, Eragon learns to cast spells by drawing energy from his environment, which kills the surrounding wildlife, but doesn't cause him any serious harm (it affects him emotionally, though). He also learns to invest his energy into gemstones, after which he can use it to power spells without exhausting himself. In book 3, yet another power source is introduced: magical stones that come from dragons and also serve as their Soul Jars. In Inheritance, it is mentioned that one rider essentially turned herself into a matter/energy explosion during the Fall, rendering Vroengard a radioactive wasteland and killing at least one of the Forsworn in an extreme example.
• Charles Stross's The Laundry Files series features magic as multiverse trickery invoked by high-level mathematics, with a nicely handwaved reference to the Heisenberg Uncertainty Principle and good ol' Schrodinger's Cat to explain why the more powerful spells require human sacrifice. While the reasoning breaks down a bit for smaller spells that just require some blood, it does provide an alternative motivation for the Holocaust: the Nazis were attempting to destroy enough souls to create a portal to a parallel universe and summon a weakly godlike entity. Beyond this, you can "run" a spell in your head as long as you don't mind some minor Eldritch Abomination taking a small bite out of your brain. Doing this too often, even accidentally, results in Kranzberg's syndrome and a permanent trip to St. Hilda's.
• Level Up Hero: Sam can heal others at the cost of his life force. With the Argonaut System, he developed regeneration that lets him heal others better.
• In The Locked Tomb, necromancers commonly produce "blood sweat" whenever they push their abilities beyond comfortable limits, exsanguinating through the pores of their skin. This, on top of a capacity for necromancy interfering with the body's ability to develop muscle mass, is why necromancers are typically so fragile and unfit.
• Magic by the Numbers: Sorcery spells consume some portion of the caster's life-force, permanently shortening their life-span. The bigger or more comprehensive the effect, the more life-force it consumes. Young sorcerers tend to waste their power on extravagant, flashy effects while older, more experienced sorcerers hoard their magic to preserve the time they have left.
• The prologue of Magic for Liars sees Ms. Webb uses an alarm spell that amplifies her scream. Torres later says that this spell has fallen into disuses because of the physical toll it takes on the mage; Ms. Webb is hoarse for days afterward.
• The Magician's Nephew: It's implied something that Uncle Andrew either did or endured at some point in his magical training had this effect; while describing his backstory in how he became a Magician, he said that his health broke down. But whatever he gained from that sacrifice, he considered it Worth It.
• Mangoverse: Isaac's magic takes some of his energy, the more that he uses it. Overuse causes him to pass out and suffer intense headaches.
• The heroine of Market of Monsters has the power to (among other things) heal wounds at an accelerated rate, but doing so uses up energy and is harder if not impossible to do if she's ill, hurt extremely badly, sedated, or weak.
• In Memories of Ice, the third book of the Malazan Book of the Fallen series, the use of healing magic in great quantities is fatal for Karnadas, the Destriant (High Priest) of the Grey Swords after he expends the last of his energy on healing Shield-Anvil Itkovian after he's already healed several of the other Grey Swords.
• Feruchemy from Mistborn: The Original Trilogy falls somewhat under this trope. A Feruchemist can draw off any of a variety of attributes from himself, then store them in pieces of metal to be withdrawn later. For example, if you become half as strong as you normally would be for an hour, you can then later become one and an half times as strong as you should be for an hour.
• The Name of the Wind uses a system similar to this — Sympathy is essentially a magical form of energy transfer. In desperation, you can transfer the heat out of your body to use the energy to heat something else or start a fire, but this is extremely dangerous and generally considered a bad idea.
• Of Fire and Stars: Spells require part of the mages' energy, so the more they cast (or if these have greater power) it drains them progressively.
• In books by Tamora Pierce, desperate bad-guy mages often kill themselves by using their own life energy for magic once they've run out of any other kind of magic. Usually, this is accompanied by one of the major characters shouting at them to stop or else they'll kill themselves, a warning they never heed. Although it's definitely not limited to the bad guys, as Ochobou burned out her magic and herself taking down five mages of her level in Trickster. And in the Circle of Magic book The Will of the Empress, when the Discipline four (who at this point in the books are basically the strongest mages in the world when they stand together) use their magic to break the border of Namorn, they are left extremely hungry and tired for days. Briar says that if they hadn't drawn power from all across the empire, they would be dead.
• Reborn as a Vending Machine, I Now Wander the Dungeon: Boxxo can spend Points to use his functions, cast magic, or to repair himself, and he also passively loses 1 Point per hour. He concludes that running out of Points will shut him down.
• Psionics in The Second Gate normally channel energy they've "metabolized" and stored, but in a pinch, they can draw power directly from their biological functions. The mind instinctively tries to cut off psionic connections to prevent permanent damage at the same time, which can result in anything from mild burnout to a coma — which is usually too late to save the user anyway.
• Magic-users in The Soprano Sorceress and its sequels use their own body's reserves to cast; they have to eat like barges just to keep their weight up.
• In the Star Darlings franchise, wish energy is what powers Starland, so using excessive amounts of energy granting small wishes makes Star Darlings exhausted.
• Sweet & Bitter Magic: Doing magic drains a witch of some energy, depending on the spells and their strength. Tamsin, as the most powerful among her generation, is only slightly weakened after healing a boy from the fever that would kill him otherwise, whereas other witches would be bedridden, recovering for days. However, they can also get magic from sources (people who are made of magic, essentially) or the earth itself. The latter is dark magic though, and imbalances the world, causing awful catastrophes.
• In the Sword of Truth series, a wizard can cast Wizard's Life Fire, a powerful explosion that kills the wizard but usually reduces whoever is nearby to ashy stains on the walls. The taste of said ashes yields a clue as to why the dying wizard chose to cast Wizard's Life Fire: if the ashes are bitter, the wizard cast the spell to save himself from torture; if they are sweet, the wizard gave his life to save another.
• That Hideous Strength: A variation: it's implied that using atlantean magic had a subtle negative effect on the user's health, though it wasn't specific what that was. The characters didn't seem to know exactly what it was, themselves.
• In Velveteen vs., this is how Velveteen's powers work, though she's not aware of it until an incident halfway through the second anthology in which Jackie Frost discovers that Velveteen's malaise and fainting spells have been caused by the effort of keeping her boyfriend, Tag, in a state of reanimation after his death in a fight with an evil dentist (no, really), and that continuing this will kill her.
• The Villainesss Days Are Numbered: Because she's so ill, almost anything physical Clea does costs her Hit Points, which recovers eventually.
• How the Returned work in Warbreaker. Most people in that world have an energy called Breath that can be used to fuel magic, but if it's completely drained they just lose magical ability (and a certain degree of keenness of the senses) until they can acquire more from someone else. The Returned, however, are kept alive by one immensely powerful Breath — this allows them to perform miracles beyond the capacity of ordinary magic, for the cost of their life. The sword Nightblood, resident Artifact of Doom, also functions like this, drawing on the Breaths of its wielder to fuel its powers. If the wielder runs out of Breaths while still using the sword, the results... aren't pretty.
• The Wheel of Time:
  • Channeling results in physical and mental fatigue, depending on the amount and duration of the channeling. In extreme examples, channellers have "pushed" themselves past usual levels, but it puts them at the risk of losing the ability to channel, or, in extreme cases, dying. Quite spectacularly in a couple of cases.
  • The prologue of the first book features one of those two cases, and where it happened became a volcano known as Dragonmount. The second case is during the Last Battle, when Egwene al'Vere sacrifices herself with a weave she literally just came up with to undo the reality-shredding damage that overuse of balefire had done.
• All spells in Wind Of The Forelands cost life energy, apparently of the nonreplaceable type. This, incidentally, is why the resident Mage Species is so frail. Mages from The Magister Trilogy are the same way, though the eponymous Magisters are those who have learned how to cast from other people's HP.
• The Young Wizards series has this as a common technique. Everything has to draw energy from somewhere, even magic, and the wizard's own energy sometimes represents the most convenient source. With everyday magic, this simply leads to fatigue if overused, the magic equivalent of exercising strenuously. Magic that can save the day, however, is often Cast from Lifespan instead. This arises several times in the series, including as the primary plot of the second book, Deep Wizardry. One shield spell in High Wizardry costs a year of the casters life for each blast it absorbs (granted, these are attacks from a distracted Lone Power), and the characters discuss it during the fight: "What if you're scheduled to get hit by a car or something in less than a year?" "I'd better look both ways then."

• Magic in Buffy the Vampire Slayer sometimes works this way, Depending on the Writer. Notable examples would be Willow teleporting Glory away in Blood Ties (which leaves her bleeding, with headaches for weeks afterwards) and the portal-opening spell in Get It Done (which she casts from the hit points of Kennedy and Anya, the two strongest beings in the room).
• The main character in Carnivàle has to draw life-force from his surroundings to use his healing abilities. It is implied that he may have inadvertently caused the Dust Bowl in this way.
• Doctor Who:
  • In "Mawdryn Undead", the title character and his seven companions were caught by the Time Lords while attempting to discover the secrets to their regeneration ability, and are punished by being granted a never-ending cycle of imperfect regenerations. Mawdryn tells the Doctor that the only way for them to die and end their torment would be for him to give each of them a surge of temporal energy taken from his remaining regenerations — this being his fifth incarnation, he'd have none left for himself. Fortunately, the temporal discharge resulting from the Brigadier coming in contact with himself from a different era is enough to avert this.
  • In "Rise of the Cybermen", the Doctor uses ten years of his life to recharge a power source in the TARDIS. Subverted in that ten years to a Time Lord is a scant few moments, and the Doctor's regenerations never last for a full natural lifespan anyway.
  • The Face of Boe makes a Heroic Sacrifice in "Gridlock", giving up the last of his life energy to help save the thousands of people trapped in New New York's underground traffic system.
  • The Master, after Lucy disrupts his revival during "The End of Time". He wins the Superpower Lottery as a result, but all his new abilities are fueled by his own life-force.
• Domino Day: Particularly strong spells which Domino casts drain some of her energy, and she must feed on others.
• Game of Thrones: Melisandre's shadow assassins are implied do this to her partner. When Stannis requests she produce another, she says, "Your fires burn low, my king." In the novels, this manifests physically as Stannis becoming frighteningly gaunt and sunken, but Pragmatic Adaptation makes this less clear.
• In an episode of Gilligan's Island, the crew found a crate of vegetable seeds. They were so excited at the thought of having fresh vegetables that they didn't question the fact that they grew incredibly quickly, and it wasn't until they had actually eaten them that they discovered via a news report that the seeds were radioactive, and that what they had eaten would likely kill them. As the Professor tried to find a cure, some of them started to gain super powers due to the fact that the nutrients in the vegetables had been enhanced greatly. Gilligan, who had eaten the spinach, gained Super-Strength from the iron in it. Mary Ann gained telescopic vision from the vitamin A in the carrots, and Mrs. Howell gained Super-Speed from the enhanced sugar rush from sugar beets. The Professor commented that the vegetables "could make them the healthiest people in the world", to which the Skipper replied, "Yeah, if they don't kill us first!" Eventually, the Professor found out that they could neutralize the radiation with the stuff they had been using for soap on the island, and they survived, but unfortunately, they lost the powers.
• Luna Nera: The energy needed for the Gender Bender spell which Antalia had cast on Valente took her youth, aging her by decades.
• Motherland: Fort Salem: Raelle's healing magic exacts a toll on her own body in proportion to the wounds that she heals.
• The Outer Limits (1995): In "Corner Of The Eye" the female alien gives Father Jonascu an ability to heal by giving up her own life force. Or so her compatriots say. She is later shown to be alive and well, assuming it's not an alien with the same disguise.
• The Outpost: It's revealed the people possessed by the spore kinjs are fueling their reproduction with their own bodies' energy, which is slowly killing them.
• A rare example in Power Rangers is the Lifeforce Megazord. It's powered by the Rangers' life energy, making it very powerful but slow and prone to damage the rangers operating it. It's only used for a handful of episodes before being stolen by the demons and destroyed in "The Fate of Lightspeed." Unlike nearly every other Megazord ever seen, it's unclear if the Lifeforce Megazord is constructed of smaller Zords or is simply a Humongous Mecha all on its own.
• An unusual example in Smallville:
  • It is possible to grant temporary Kryptonian powers to humans, but it has negative effects like putting Jeremiah in a permanent coma, giving Jonathan lethal heart problems, or exacerbating underlying mental trauma, Eric and Lana.
  • In "Bizarro", Chloe's healing tears revives Lois Lane, but the effort renders her unconscious and later actually kills her. Luckily, she is able to resurrect herself.
• Supernatural: Castiel's abilities take on this shape after he rebels, as he is now acting on his own without the support of Heaven and no longer has unlimited power at his disposal. When he takes the Winchesters back in time, the effort leaves him coughing up blood and then comatose. He also reacts with some discomfort when performing a locating spell, which may have drained him slightly.
• Witches' spells appear to take a severe toll on the body in The Vampire Diaries, to the point where it sometimes seems that Bonnie can't do anything useful (except mind-whammy Damon) without knocking herself out.
• The Witcher (2019): Magic requires a conduit to be drawn from. Fringilla finds this out the hard way when she levitates a stone without drawing from the bunch of flowers on the table and finds her hand rotting. She and her mage followers use their own life forces to fuel magic later as well.

• Dominion powers in Anathema are cast from your "anathema", which is your health.
• Arkham Horror 3^rd Edition: Agnes Baker's special ability invokes this with Blood Magic. She can choose to substitute the usual Sanity cost of a spell for Stamina damage and gain a boost to the spellcasting roll.
• Ars Magica: Leper magi can transmute their life energy into vis, a precious form of Mana, suffering a Wound and creating vis points proportional to the wound's severity. They can even kill themselves in this manner — the vis can be harvested from the body.
• Many spells in Call of Cthulhu, and every spell costs sanity.
• Most spells in Castle Falkenstein are cast from ambient thaumic energy, but it takes time to gather this, so mages in a desperate hurry may cast from hit points instead; this is called "unraveling" and can be fatal (though if it isn't, you get better eventually).
• Champions characters who run out of Endurance can continue to use their powers by taking Stun damage, at a rate of 1d6 Stun per 2 Endurance required. This only works for powers that draw on the user's own Endurance pool, as opposed to the Endurance Reserve power. A character can literally knock himself out from overexertion.
• In the Swedish Tabletop RPG Chronopia, Orcs have access to a very interesting magical discipline; Painmagic, ripping off a finger can grant you skill bonuses, cutting yourself can give you visions of the future and hacking off an arm or a leg can make you temporarily invulnerable. Not surprisingly, they have also developed plenty of rusty prosthetics complete with hidden sawblades and other nasty surprises to replace those limbs lost.
• Critical Role: Tal'Dorei Campaign Setting: The Blood Domain Cleric sub-class has an ability called "Sanguine Recall" which allows them to instantly recover a spell slot by injuring themselves. The more damage they take, the more powerful the spell slot they recover.
• In the German tabletop RPG The Dark Eye (aka Das Schwarze Auge in German), every magic user can do this, but not without consequences, usually additional damage and that damage might permanently reduce the maximum hitpoints of that character (only when he drops too low as a result of blood magic though). Excessive use of this in one of the novels leads to a mage permanently losing his ability to use magic. Later on, he uses a magic sword that also drinks from his Life Energy, losing fingers on his good hand as a result.
  • Taken to eleven with a druidic deadly ritual, that lets the caster put not only all his health, but all his stats and skills on top into one final and usually devastating spell. Suffice to say, what remains of them afterwards could not even be resurrected by a god.
• In the first printing of Dark Heresy, a psyker could use the Corpus Conversion talent to take damage to add his Willpower Bonus again to a manifestation test. The errata changed the cost to a permanent Toughness point in exchange for another power die.
• The Sorcery power in the 1980's DC Heroes game had a function similar to this. Every time the power is used, the AP's (power rank) used is compared against his or her Spirit score (a combination of damage resistance and hit points versus mystical damage). Effectively, if he or she is using AP's lower than his or her Spirit, there's no problem. Otherwise, there's a chance of Spirit damage (affects the "hit points" versus mystic things, but not durability, that's always your maximum Spirit). If there's a significant difference between the two with the Sorcery being higher, the caster will likely be rendered unconscious by using a full powered spell.
• Deadlands: The Weird West has the Whateley family's Blood Magic, which consumes both "Strain" and "Wind" (which would be "Subdual Damage" in other games) as the caster's tainted blood is consumed by dark forces. All without even breaking the skin!
• Demons in Demon: The Fallen can enhance their powers by drawing energy from hitpoints... except that said hitpoints belong to their followers, not them.
• Deviant: The Renegades: Chimeric and Invasive Deviants can take damage to refresh powers that have a once-per-scene or once-per-chapter limitation. Coactives (infused with energy, supernatural or mundane) can take damage to temporarily boost a Variation. Any Deviant with the Perilous Variation Scar takes damage to activate the Variation(s) linked to that Scar.
• Magic in The Dresden Files has everything it needs to be this. The attempt to gather and channel the necessary power for the spell can itself backfire and hurt the caster, especially if they're in a hurry, evocations always involve a mandatory hit to one's mental stress track (making it easy for a wizard to potentially knock him- or herself out with a few quick spells even if they all work as planned), one of the easier ways of adding power to a thaumaturgic ritual is to accept consequences reflecting mental or physical harm... Most of this is recoverable with time as long as the caster doesn't go overboard (simple mental stress doesn't even last from one scene to the next, for example), but it still serves as a major check on the power of magic in a game that, as per the source material, tends to focus rather a bit on it.
• Dungeons & Dragons, as usual.
  • The psionics in AD&D used a spell-point system even when the actual spellcasters use Vancian Magic. Since an ability like Cast from Hit Points fits in so much better with a spell-point system, the 2nd edition had "Cannibalize", a power that allowed mid-level psionicists to get extra power points from damaging Constitution. The 'Death Field' power causes to everyone in the area of effect damage proportional to the sacrificed Hit Points 1:2 (or 1:1 for users of evil alignments).
  • An unusual example of this is in the Dragonlance Adventures sourcebook for AD&D. The dragonlances come in two types: Footman's and Mounted. Against normal enemies they do regular damage, but against the a dragon — the dragonlance doesn't roll for damage, it instead uses the wielder's hitpoints as the base damage and then adds any bonus damage from the wielder's strength and the dragonlance's enchantment (Mounted Dragonlances are even more powerful — they add the hitpoints of wielder and mount, and only mounts as large as a dragon can use the lance). So if a character keeps getting hurt in a fight, the base damage of the lance goes down. This aspect of the dragonlance also shows up in the Gold Box versions.
  • The imaginatively-named Level 1 Necromancy spell, Blade of Blood, allows the caster to take 5 damage to make their attack deal extra 3d6 damage from exploding blood. It usually spells One-Hit Kill for creatures of comparable level.
  • 3E supplement Epic Level Handbook has several extremely powerful spells, such as Hellball and Let Go of Me, work this way. The greatest example of this, however, is Vengeful Gaze of God, which deals 305d6 damage to an opponent while dealing 200d6 damage to the caster, who suffers from bleeding eyes and convulsing skin and, most of the time, dies. This spell will almost always kill anyone and anything it is used against, excluding the most powerful of monsters, who simply might be killed by it.
  • 3E Fiendish Codex II offers the Hellfire Warlock, which upgrades the warlock's standard attack from "kinda okay" to "nuclear inferno" at the cost of 1 Constitution drain per shot. Since Constitution affects both current and maximum HP, it's generally a good idea to have someone on standby with a restoration spell or a cheap wand of lesser restoration with the spell provided by a Paladin (it is even suggested in the fluff). To make it even better a Hellfire Warlock with one level of Binder can gain an ability that automatically heals 1 point of ability damage a turn. Then there's classes like Legacy Champion which increase your effective level in another class, even beyond the Cap. Combine the two and you get a supercharged Hellfire Blast usable at will.
  • The Blood Magus class from 3E's Tome & Blood can sacrifice a little blood (hit points) to cast spells with slightly harder saving throws or replace material components. 3.5 Complete Arcane replaced its hit points damage with Constitution. And the 4e Blood Mage paragon path allows you to take damage to deal as much extra with encounter and daily spells. This was so abusable it needed to be nerfed with errata. Twice.
  • Forgotten Realms:
    • The AD&D era had some of the more formidable spells involving sacrifice of the caster's hit points — either normal damage, permanent, or the loss incurable as long as the spell is active. This includes several spells from Secrets of the Magister. Which may be a legacy of old Elven Blood Magic, which includes 'Blood Dragon' — near-unstoppable mass killing spell requiring the caster's death. Also, the Drow sometimes have "body weapon" enchantments as a last-ditch defence, which usually involves loss of a body part or other physical injury. E.g. Jalynfein, by breaking a finger and saying a word, could fire a burst of 24 magic missiles (cast normally, would be limited to 5). The Phaerimm dehydration spell 'lifedrain' (the one which made Anauroch a desert) also involves permanent sacrifice of a hit point, but holds for years — and dies with the caster.
    • The 3.5E sourcebook Lost Empires of Faerûn includes rules for creating mythals, persistent magical fields first developed by ancient elven high mages that block or buff specific spells and spell categories. Among the rules is the option to reduce the DC of the mythal creation by having the caster sacrifice his or her life to its completion. This is mentioned to often be welcomed by the elven high mages as the pinnacle of a many-centuries-long, very productive life.
  • The Spelljammer spell "Create Atmosphere" involves permanent hit point sacrifice from the caster. It makes a cubic mile/level of the air self-renewing for more than a year, after all.
  • 2nd Edition Al-Qadim setting supplement Arabian Adventures. Casting the spell Cleanse Water drains 1d6 Hit Points from the caster. The lost points can only be regained through natural healing, not by magic.
  • 4th Edition
    • Bloodclaw Weapon would let you pay a small amount of HP with every attack, which then would be doubled or tripled if the attack hit. This ended up being so much more powerful than other weapon enchantments (especially for Fighters and Barbarians, which get more HP than other classes) that it was nerfed to a once-per-battle use and it STILL managed to be usable.
    • The Blackguard subclass of the Paladin from Heroes of Shadow uses a variant of this mechanic as well, which is powerful enough to be their entire Striker damage bonus.
  • The 3E sourcebook Book of Exalted Deeds includes a category of spells called "sanctified magic" that can be cast by either divine or arcane spellcasters and require varying degrees of self-sacrifice to cast. This can be as simple as an "abstinence component"^note , but it may also mean anything from ability drain on up to, in the case of Exalted Fury, death (you can be resurrected by the usual means, though).
  • Dragon magazine #229 article "Wu-jen: The Oriental Mage Revisited". This Asian-themed mage can cast any spell they know at any time, without the spell memorization standard wizards require. However, there is a cost: casting a spell costs the wu-jen 3 Hit Points of damage per level of the spell. Considering how few Hit Points wizards have, this is a serious penalty, restricting them even more than normal wizards unless they have a significant source of healing available. Even worse, they only get half the normal benefit from magical healing.
  • Spheres of Power has the Draining Casting drawback. While it only deals nonlethal damage to you, Pathfinder's rules on nonlethal damage can still have it kill you.
  • 5th Edition mainly removed this feature, but it survives in some places.
    • Wizards of the School of Evocation gain the Overchannel ability at higher levels, which enables them to maximize the damage of their spells of 5th level and below. The first use of the ability per long rest comes with no drawback; subsequent attempts without a break cause the wizard to take unavoidable necrotic damage that scales higher with stronger spells and more uses of the ability. As with the Wu-Jen above, 5E wizards are squishy and can't usually spare the HP that they would lose from repeat Overchannels; players may do so at their own peril.
    • The semi-official class Bloodhunter, made by Matthew Mercer for the Critical Role livestream, and later put up on DNDBeyond, can imbue their weapons with blood or cast bloodmagic, but only using their own blood (consisting of taking damage equal to their level, so between 1 and 20).
    • There’s also the spell Life Transference, available to wizards and clerics. The caster takes a not-insignificant amount of damage (4d8 at the spell’s lowest level), but is then able to restore double that amount of a friendly creature’s hit points. Some characters are better suited to use this than others (Life Domain clerics, for instance, gain HP every time they heal a friendly creature, mitigating the risk to themselves somewhat) but overall it’s a potent, if situational, healing spell.
    • Tal'Dorei Campaign Setting Reborn introduces the Blood Magic Wizard and the Blood Domain Cleric. The Blood Channeling feature of the Blood Magic Wizard allows them to forgo the costly material component of a wizard spell in exchange for taking 1d10 necrotic damage per 50 gp of the component. The Blood Cleric's Crimson Bond allows them to form a temporary bond with another creature in exchange for 2d6 necrotic damage, and the Sanguine Recall feature allows them to recover expended spell slots in exchange for 1d8 necrotic damage per spell slot recovered.
• Dying Earth supplement Cugel's Compendium of Indispensable Advantages. The Tweak "Magic Derives from Personal Force" allows a magician to cast spells using Health Points instead of Magic Points.
• In Eclipse Phase all Active psi-sleights (other than Downtime, that would be counter-intuitive) have at least a chance of inflicting damage to the user.
• Several powerful Charms and spells in Exalted require you to sacrifice health levels as part of their activation cost.
  • In high-paranoia games, where every attack might kill and so every attack must be answered with a Perfect Defense, every attack is cast from hit points: they cost charm activations and Essence, the two resources that fuel perfect defenses.
  • There are also two spells that can be cost for minimum Essence (mana, magic points) expenditure but automatically kill you and deal significant damage to everyone around you.
  • In fact, Dragon-Blooded have quite a percentage of Charms with the "Martyr" keyword. That means that they can be cast with greater effect, but killing the Exalt for sure. That is why they can be used with no Essence left. And some of such Martyr usages can last for generations.
• Fabula Ultima:
  • The Darkblade's Shadow Strike skill lets them sacrifice some health to make a powerful dark-elemental weapon attack.
  • The Spiritist's Vismagus skill lets them cast a spell using HP instead of MP if they don't have enough MP to cast it normally. The HP cost is twice the spell's normal MP cost, and the Spiritist doesn't regain any health if they spent this HP to cast a healing spell which targets themselves.
  • The Heartbreaker heroic skill, which can be obtained by mastering the aforementioned Darkblade class, lets you sacrifice half your current hit points to deal 10-30 extra damage on a single-target attack against an enemy with which you have a Bond.
• Fireborn had this as a potential side effect. It takes one(or a group) so much power to cast a spell to be built up. Depending on the situation, one can roll a lot of dice and hope to quickly cast it, or do so slowly and carefully. However, if you go over the needed number of successful rolls and charge up too much power, the excess physically damages you. Of course, one can eliminate this by learning ways to channel that overload into the spell, usually for enhanced range/duration/effect.
• GURPS:
  • Casters can do this, although it's more difficult than using other energy sources, presumably because the pain makes it hard to concentrate. Usually, spells are powered with Fatigue Points (i.e. wizards get tired when they cast spells) or with enchanted "energy batteries" called powerstones. Once you burn through all your available FP (or earlier, if you choose), if you keep casting spells without resting, you start burning HP. Ordinarily, you can only use up hit points until you lose consciousness, at which point the energy drain stops (you don't die). The supplemental advantage "Word of Power" drains so much fatigue that it's guaranteed to drain life from a normal person. It will keep speaking itself even if the caster dies in mid sentence.
  • GURPS Warehouse 23: Gojira's atomic breath can deal however much damage it wants it to deal, at the cost of causing it one point of health loss for every ten dealt.
• Alchemical items in Hollow Earth Expedition supplement Mysteries of the Hollow Earth.
  • The Life Channeling enchantment allows the user to power the item by inflicting either non-lethal damage on themselves or lethal wounds on other creatures.
  • Blood Offering drawback. An item recharges its powers (so they can be cast again) by inflicting lethal wounds on other creatures.
  • Exhausting drawback. Each time an item is used it inflicts a point of non-lethal damage on the user.
  • Toxic drawback. Each time an item is used it inflicts a point of lethal damage on the user.
• In the Iron Kingdoms, the skorne practice a form of Blood Magic which draws power from the pain and suffering the caster inflicts on themselves and on others. Needless to say, the spells usually drain hitpoints in order to work.
• Interstitial: Our Hearts Intertwined has a few moves require you to take Harm as a cost, regardless of roll.
  • "Leaf Bracer" from The Chosen lets you take Harm to upgrade a mixed success to a full success.
  • "My Darkness is My Weakness" from The Discarded lets you take Harm to add +2 to a Dark roll.
  • "Nothing Hurts Like the Cold" from The Light lets you cash in Heart Links to deal 2 Harm each to someone, but you take 1 Harm each yourself.
  • "Command Deck" from The Other has you take Harm to temporarily gain abilities to overcom an obstacle.
• Kingdom Death: Monster has monsters who's AI deck acts as their HP pool. If a monster is harmed, you discard AI cards. It also means that every time a monster acts, it is casting from HP.
• In the live-roleplay system Labyrinthe, almost all supernatural abilities have an hp cost in addition to a mana cost. The amount of damage done is relative to the level of the ability relative to the level of the caster.
• The central plot device in the Lamentations of the Flame Princess module Better than Any Man is a spell that is essentially Wish, as a first level spell. The main catch is that the caster dies when casting it. (The other catch is that casting it requires several assistants, and all of them must agree on what they're wishing for. If even one of them dissents, the spell fails and the caster died for nothing.)
• A few cards works that way in Mage Knight (the boardgame), doing various very powerful effects (lot's of damage^*, lot's of mana^* or learning new actions^*) at the cost of a new wound card to your hand. Wounds have some serious drawback in the short^*, long^* and very long term^*, but healing is plentiful and most players will heal themselves the same turn they gain the wound.
• Mages in Mage: The Awakening can burn some of their health for a quick boost in Mana. It also works the other way around, though this is easily the least efficient means of magical healing in the whole game. In the previous game, Mage: The Ascension, a substance called Quintessence makes casting spells easier. A mage that runs out of Quintessence can rip some from their own body, damaging it in the process.
• In the cooperative play game Middle-Earth Quest, your hero deck is also your 'life pool.' Any card you play in combat, or even to move around the map, costs you a hitpoint.
• Pokémon Tabletop Adventures has the Psychic class, capable of using certain Pokemon attacks, similar to the Martial Artist class. The martial artist's attacks can only be used a certain number of times per day, whereas the psychic's attacks can be used at will, but require this trope. (Thankfully, the nature of the psychic's key stats means they usually will have a large amount of HP to cast from.)
• Many of the most powerful Tempesta Charms in Princess: The Hopeful inflict unavoidable Resistant damage^* to use. Similarly, once per session anyone playing a follower of the Queen of Storms (Noble or Sworn) can declare that the Queen is manifesting power through her character. This allows her to use any Tempesta or unaligned charm with as many successes as desired and none of the normal casting costs, but inflicts one point of Resistant Lethal damage per success requested, which can and has killed servants of Storms in the past. On the other side of the War of Hope, the servants of the Darkness have the Self-Consuming Hunger Caligo, which lets them inflict Resistant damage on themselves to generate a special pool of faux Willpower that can be used to pay for other Calignes.
• Psionics: The Next Stage in Human Evolution
  • With the exception of Biofeedback, using psitalents inflicts nonlethal damage on the user.
  • If an esper is out of power points, they can pay the difference in extra nonlethal damage to use their powers.
• Downplayed in Res Arcana:
  • The Life essence can be attacked, which forces you to pay that amount in Life, or twice that amount in other essences. This makes everything that costs Life a pseudo-way of paying HP for stuff even though the main purpose of Life essence is still to be spent on stuff. Some of the game pieces have flavour that highlight the fact that you're paying with life, such as the Ring of Midas letting you exchange Life for Gold, reflecting Midas's curse.
  • The Catherine Wheel from Perlae Imperii has the unique property that its attack hits every player including its owner. However, its second power rewards you for using "ignore attack" effects.
• Ixtli, the Aztanli-specific Boons in Scion, have a number of abilities that grant extra Legend for physical sacrifices. The amount gained from bleeding another creature is half what you get for doing the same thing to yourself.
• In Sentinels of the Multiverse:
  • The hero Nightmist has multiple spells that damage her as well as achieve whatever the intended effect was, and her standard form's power draws two cards but hits her in the face for 2. She mitigates it with some fairly impressive healing options, plus a relic that allows her to deflect one instance of damage per turn, meaning that she can make a fairly impressive tank if she can keep her equipment out.
  • Absolute Zero's playstyle is built around this, because opening the suit to let his power out also lets hot air in to hurt his altered body. His base set's power is to hit himself in the face, and he has multiple one-shots that hit him as well as the enemy. He uses Module equipment to turn ice damage into health and convert fire damage into outgoing frozen misery for whoever it hits (or direct it inwards to heal him if you have both out; with the right gear, setting him on fire will actually make him healthier).
  • The Harpy has several cards that damage herself as well as enemies. One of her deck's key ongoings, Applied Numerology, exists both to mess around with her powers, and to mitigate self-damage effects.
  • Dr Medico's Void Guard deck tends to involve hitting himself with energy or toxic damage to boost his healing output. He can also heal himself all the way up given a good run with Regeneration, though, so he can do really well if handled correctly and outfitted with the right cards.
  • Fanatic's Sacrosanct Martyr and her Prime Wardens variant's power involve hitting herself with radiant damage in order to do things. She has a bit of healing to offset it, plus armour that stops her dying and resets her health to 10. For bonus points, her most damaging one-shot scales based on how much punishment she's taken.
  • Lifeline's cards generally damage him for some bonus: for example, he has one that hits him and three opponents for 3 infernal damage, or one that pings him with Infernal but lets him play 2 or draw 3. He can wear armour to help him survive, though, and when he goes on a tear through enemy minions Vitality Battery can cover a lot of ground.
  • Akash'Thriya's giant HP pool isn't just there for show: a bunch of her stuff to speed up the environment deck in order to more effectively use her Primordial Seeds involves hitting herself for toxic or psychic damage, and her main damaging power hits her before it hits anyone else. It also makes her really good at drawing fire from villains who target the highest HP.
• Shadowrun: All spells and summonings have a Drain Value, damage that the mage has to resist after casting. If the Force of the spell or summoned spirit is greater than the mage's Magic attribute, unresisted drain is physical damage; otherwise it's stun damage. Blood Magic has techniques that mitigate drain by inflicting it on a prepared victim. The outward signs of unresisted drain can include fatigue, sudden nosebleeds, unconsciousness, or a spectacular death.
• As mentioned above, casting or controlling a spell in the Slayers d20 game is based on stamina (a Fortitude saving throw modified by caster level), and deals subdual damage to the caster based on the spell's difficulty and your margin of success. You get a hefty bonus to your control checks by voluntarily taking lethal damage, or it might happen anyway if you botch horribly enough.
• The previous edition (using the Revised Core Rulebook) of the Star Wars RPG rules generally had Force powers cost vitality (the system's version of Hit Points) to activate. If you didn't have enough vitality, you could even use wound points (representing real and dangerous — even potentially fatal — damage) to make up the difference. The only thing stopping characters from 'casting to death' is the fact that no Force power had a vitality cost so high that the damage could push a character far enough into the negatives to result in death.
• Stars Without Number: psychics who use non-mastered powers after running out of points have a high risk of suffering Torching, which reduces either Wisdom or Constitution, determined randomly. Dropping Constitution too low will kill you; dropping Wisdom turns you into a deranged killing machine, and that you get to use powers for free is not much of a consolation prize.
• Epideromancers in the tabletop RPG Unknown Armies power all their magic by hurting themselves.
• Vampire: The Eternal Struggle
  • Each player begins the game with 30 pool, which represent their methuselah's influence. If you lose all of your pool, you lose the game. However, you use pool to put cards in play, so in game terms it is both your "mana" and your "life."
  • Vampires have blood points that serve as their health. They can also use various action cards that cost blood points.
• In Warhammer Fantasy, Ogre Butchers can cast a variety of gastromantic spells, or Gut Magic. Along with the normal requirements of spells, they sometimes require the Butcher to inflict bodily harm on themselves. In particular, the Trollguts spell, which is the best out of the 6 available to the Ogres, but permanently takes off one health from the caster that cannot be regenerated in any way (whereas the other ones are usually avoidable unless you displease the Random Number God, and can be regenerated with another spell).
• In The Witcher: Game of Imagination, when mages cast spells beyond their current number of Arcane Points, the difference is taken from HP. Certain spells by default go beyond the limit of Arcane Points one can have, causing casters to faint or drop dead after or during the casting. They should be instead used by a group of mages supporting each other or around outside sources of magic energy.
• The Witcher Role Playing Game: Similar to its predecessor, casting magic carries a significant risk. Mages who cast spells with a Stamina Cost higher than their Vigor stat take damage from the strain. Fumbling when casting a spell also damages the mage. It is easily possible for a mage to kill themselves trying to cast a spell that's above their means.
• World of Synnibarr. Some spells can be enhanced by spending points of Constitution while casting them, thus increasing the effect of the spell (such as damage done).

• In Pokémon Live!, Mewtwo hits MechaMew2 with enough of Ash's memories to make him faint, and when he wakes up, he can't remember the fight or what happened afterwards.

• The Adventures of Dr. McNinja:
  • Frans Rayner's laser-shooting eye doesn't come with a power source of its own, so using it burns so many "calories" that he's left physically powerless after one use. As such, he tries to use it only to finish off an opponent.
  • The Doctor's grandfather happened to gain magic powers by eating a talking pig, but his use of the magic always drains or harms him physically. When he casts a major spell to protect his grandson from a ghost wizard's curse, the toll kills him.
• City of Trees establishes that certain beings with magical abilities, like witches, use their own energy when casting magic. It is possible for a magic user to overexert themselves, with potentially deadly consequences.
• Girl Genius: When preparing to do something spectacular, the Beast can shorten itself for extra energy, by imploding its own wagons and converting them to energy.
• In Hazard's Wake, Path is an Expy of Tellah, so he does this.
• Kid Radd demonstrates the drawbacks of such techniques. When Radd and the others visit a fighting game, Sheena, being an NPC sprite, is unable to inflict or receive any damage from her opponent. Her opponent grows increasingly desperate to damage her, and finally uses an attack that sacrifices some of her life to attack Sheena. The attack fails and because Sheena's opponent has less health than Sheena when the time runs out (i.e., less than full), Sheena wins.
• In Not a Villain, the Game allows Specials which move points between attributes, allowing characters to cast from any attribute.
• In Ozzie the Vampire, summoning demons means sharing and dividing the caster's life force among them for as long as they remain summoned.
• Extremely powerful magics can take a toll on the caster's life force in Roommates too. Like, summoning a sea from nowhere in a magical land will drain the caster so much he is lucky to not pass out. The same in the real world is probably close to lethal or impossible.
• Magic in the universe of The Sanity Circus 'requires sacrifice', and although humans are capable of casting 'body magic' the strain of 'soul magic' and 'life magic' is apparently too great - unless, of course, you aren't human.
• Melete's curses from The Silver Eye require energy, and when she's exhausted or in pain, it's harder to generate that energy. When Velvare ignores his basic needs of sleep, rest, and food, the only thing holding him together is Melete's direct supply of energy, and it drains her.
• In Sorcery 101, sorcery can take a serious toll on the human body, leading many practitioners to die of a heart attack at a relatively young age. For that reason, many who learn it are already immortal, like vampires or "blood bonds" (which includes the series' protagonist).
• In The Greenhouse, demons normally can't be heard by anyone other than their host. They can get around this, though, by spending truly enormous amounts of energy. When Red does this after being severed from Mica, each sentence visibly reduces chunks of her body to tattered mist.
• The Severin family in Muted uses Blood Magic, and while they have a few ways around the Logical Weakness of that, being too low on blood is a recurring limitation on their spellcasting.

• Adventure Is Nigh: In Season 3, Sigmar aquires a tattoo that allows him to summon a magic bow, dubbed Bone-and-Marrows. This is summoned and dismissed through a Transformation Sequence that turns his own arm into the bow, causes him excruciating pain, and deals 1d12's worth of damage.
• AFK: Serena's healing spells are fueled by her own energy, so the more she heals it weakens her.
• Critical Role features a number of these mechanics from your average Dungeons & Dragons game, in addition to some unique ones made up for the livestream. This is especially true in Critical Role: Campaign Three.

  • Imogen's custom feat, "Call Ruidus," has her declare a certain number of dice and roll them. Whatever she rolls, she hads to the damage of one of her spells, but she also has to take the additional damage herself. As a Squishy Wizard, she only makes use of this ability in the most desperate of circumstances.
  • One of FCG's Sympathetic Binding abilities lets him take damage equal to a roll of three eight-sided dice and heal someone for that amount plus his Wisdom modifier. He too, rarely uses this ability because of its steep cost.

• Perpetual Players: Without a magic battery magicians who can't focus their energy risk burning themselves in the process of charging a spell. Something that has happened to Deacon on more than one occasion through the first episodes.
• Semblance in RWBY work this way as being a manifestation of Aura.
  • Jaune's Semblance allows him to bolster the Aura of others by giving them his own. Fortunately, he has a lot of Aura to work with.
  • Yang's Semblance is a more minor example: the more damage her Aura takes, the more powerful her attacks become, though it means nothing if her enemy can simply dodge her rather-predictable attacks, much like Neopolitan did before.
• In Tales of Wyre, Nwm often does this, since he can heal himself afterward.

  Shomei: Effectively, the Green absorbs the backlash.

• Jackie Veracruz of Tall Tales has explained that she needs something relevant to her spell to cast it, but when such a component is not available, she has been shown to use her own blood to power the spell instead.

• A side-effect of Anne Boonchuy's Calamity Box powers in Amphibia; she gets weaker every time she summons them, thus she decides to only use them in case of an emergency. Notably, during the final battle against the Big Bad, his strategy is not to attack her, but to simply stall for time until she runs out of energy and he can finish her off - and it almost works.
• In Batman: The Brave and the Bold, B'wana Beast pulls a Heroic Sacrifice this way, straining his powers to death to tear apart a revived super-Starro (after the Hunter had already drained him to revive it in the first place).
• In Beast Wars, Transformers have a fail-safe mode called "stasis lock" that forces them to shut down temporarily if low on power or heavily damaged. In the episode "Code of Hero", when Dinobot ends up having to stand against all of the Predacons by himself, he has to override this safety feature in order to keep fighting. Dinobot uses his last bit of energy to destroy the Golden Disk that contained a record of future events, costing Megatron one of his biggest advantages and saving the future of the human race.

  Computer: Warning. Power reserves 96% depleted. Stasis lock commencing.
  Dinobot: Override.
  Computer: Repeat: power loss critical. Further expenditures will result in loss of spark. Stasis lock must commence.
  Dinobot: OVERRIDE!
  Computer: ...acknowledged.

• On Challenge of the GoBots, Leader-1's force field works like this. It can protect him and those standing near him, but the energy drain on him is enormous, so he can only maintain it briefly and is left exhausted afterward.
• In Code Lyoko, there is a somewhat literal example: Aelita has the power to manipulate the environment of Lyoko, mainly creating new features, but using this power costs her half her life points.
• Elena of Avalor: The Scepter of Light draws its power from the welder's energy, thus whenever Elena uses it, she get progressively weakened. Using it at max power to defeat Orizaba drained her to the point she passed out for two whole days. After the scepter got upgraded in the final season, it draws its own power and no longer drains energy.
• In Gargoyles, the Magus taps the magic of Avalon in the episode of the same name, which severely weakens him. While initially it only exhausts him, he ends up casting so many spells this way that he dies as a result.
• In Huntik: Secrets & Seekers, there is a spell called "Soul Burn" which trades life force for enhanced powers, for a short time. Used in episode 26 by Sophie Casterwill.
• In My Little Pony: Friendship Is Magic, Princess Cadence uses her own lifeforce to power the magical shield protecting the Crystal Empire. In a very similar move, her husband Shining Armor uses his own lifeforce to also power the shield protecting Canterlot from the Changelings.
• Elita One, in The Transformers episode The Search For Alpha Trion, had the power to stop time at a localized level, but doing so drained her Hit Points.
• In W.I.T.C.H., those who use their magic without being connected to the Heart of Candracar end up using up their own life energy doing so. Halinor is shown to be exhausted after using some of her magic to protect the Citadel and it's implied that Nerissa's withered state is because of her constantly using Quintessence.

  Cassidy: Draining our life force for power, are we?