Mana Shield

The complete inverse of Cast from Hit Points: having damage hit your Magic Points instead of your Hit Points. Unlike Cast from Hit Points, you generally don't see this come up as a plot point, as you can't exactly die from it or anything. Not to be confused with a barrier spell that uses magic points to increase your defenses.

Sometimes, this can turn a Squishy Wizard into quite the tank. Can become a Game-Breaker by giving Nigh-Invulnerability to the user, especially if damage that would overkill the user's MP does not get converted into actual damage. On the other hand it will quickly turn a magic user into a sitting duck if the mana doesn't regenerate. It is also usually far more efficient to use your MP for healing spells rather than to absorb the damage directly.

Compare Mana Burn, which is where the attack is directed at the mana in the first place.

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Examples:

• Prevasion in Azure Striker Gunvolt effectively works like one. While Gunvolt isn't using his Flashfield, anything that hit him will be negated, but it drains some of his SP. Copen has a variation which removes Bullits from his gauge, which are used for his air dash.
• The Endure skill in Blue Dragon.
• In BoxxyQuest: The Gathering Storm, equipping the Aura Pearl accessory lets you cast an “RP Aura” around yourself. With the aura, attacks will damage your RP (mana) until you have none left, effectively giving you a second health bar.
• Bravely Default has Spirit Barrier, one of the abilities learned by the Valkyrie class.
• Carrion: The Keratosis upgrade allows the Villain Protagonist monster to generate a thick outer shell when it's active. During then, all damage taken will result in Energy instead of Biomass being lost. As long as the monster has energy to spare, Keratosis can even No-Sell the sticky claw bombs that will otherwise One-Hit Kill it, but the explosion will expend all remaining energy.
• Castlevania
  • Technically the Neptune card from Castlevania: Circle of the Moon heals you when you would be damaged by the element in question, but the healing's so minor and the drain on your MP so major that it's really more like the attack just drains your MP.
    • It's a miracle-worker, though, in the second playthrough's "Magician" mode, where you have very little defense and HP and a crap-ton of MP and intelligence (MP regen). Since you get all the cards at the beginning of the game in Magician mode, and you also have the Uranus/Unicorn combo to heal, plus almost every enemy in the game (including bosses) attack with an element, you become basically invincible provided you don't mind switching your cards whenever you have to deal with a different element, go on the attack, or restore accidental damage.
  • An item in Castlevania: Order of Ecclesia causes damage to your heart supply (only used for limit breaks in this game) rather than your HP.
• In the first Crysis, your nanosuit's maximum armor mode turns your energy meter into a second health bar and makes both it and your health regenerate faster than normal when not under fire.
• The Mage class in Cube World has a spell called Mana Shield; however, despite its name, casting the spell costs no Mana and simply causes a percent of damage taken to be nullified (up to a cap) instead of redirecting Health Point damage to your Mana Points.
• In the multiplayer of Dawn of War II and its expansions, several heroes can get shield upgrades which cause damage to drain their energy instead of health. Specifically, the Force Commander has the Iron Halo, the Chaos Lord the Dark Halo, the Warlock the Psychic Shield, the Hive Tyrant the Warp Field, and the Commissar Lord the Refractor Field.
• Medusa in Defense of the Ancients has this skill where her Mana pretty much makes her entire health bar at the cost of an almost non-existent HP pool.
• The original Diablo is the Trope Namer. The eponymous spell, which is the lifeblood of the middle-to-late-game Sorcerer, not only reduced all damage by a third but redirected all the rest of the damage to mana instead of health. In fact, due to a famous glitch, a high-level Sorcerer is well-advised to have as low of a health count as possible, enabling him to completely avoid stun from high damage attacks.
• In Diablo II, the Sorceress has an Energy shield that diverts a proportion of damage to Magic points.
• One of the many Geo Effects in Disgaea 3: Absence of Justice swaps your HP/MP values, so that running out of MP can get you killed on these spots. Good for quickly wiping out powerful enemies with low MP; not so good for your Dumb Muscle, if you have any...
• In the .hack//G.U. games, Doppelgangers are already tough as they are, what with being automatically 8 levels above the main character, and having an outrageous HP/SP regen points, AND having a very damaging weapons equipped, complete with devastating effects thrown in for good measure. Come Volume 3 (At Walking Pace/Redemption), and the Doppelganger has the Mana Shield in full force, making fighting him an exercise in patience, frustration, and revival items, as, for a good amount of time, your attacks will do exactly 0 damage until you run its SP to 0. On the good side though, once you do, he won't be able to do Arts, so that's one less worry to deal with.
• Dungeon Crawl has an amulet of guardian spirit that has this effect.
• There's the Vigor ability available to psionic characters in Dungeons & Dragons. It uses psionic powers in order to create temporary hit points, so its effect is similar.
  • Similarly, elans can sacrifice power points to reduce or eliminate hit point damage once per round.
• In the first Fable, this spell (dubbed "Physical Shield") is quite a Game-Breaker. The game features a combat multiplier, which goes up as you're dealing damage to enemies and multiplies the experience you receive. Being hit resets it back to zero, but only if your hitpoints go down. If you absorb the damage into your mana, the multiplier stays. Using the mana shield constantly thus allows you to get the multiplier ridiculously high and level up much faster than you could without it.
• Fell Seal: Arbiter's Mark has the Alchemystic class’s "Mystic Shield" counter skill. It has no damage overflow, so it will negate all incoming damage even if the Alchemystic only has 1 MP.
• Final Fantasy Tactics has the Time Mage ability "MP Switch" for this effect.
• Final Fantasy Tactics Advance and Final Fantasy Tactics A2 have the "Damage > MP" and "MP Shield" abilities respectively. The former is something of a Game-Breaker: it didn't put any overflow damage into HP (which made it incredibly useful for the main character to have for those 1-on-1 story fights), characters start with full MP at the beginning of the level, and they regain 10 MP every turn. In A2, MP Shield is nerfed heavily. Not only does overflow come from HP, MP also starts at 0, making this skill is a really bad choice for classes that actually use MP and only slightly better for those that don't.
  • Particularly irritating opponents in the second game have both Damage > MP and Blood Price, the latter of which allows them to cast spells out of their HP. Particularly irritating ones can also heal themselves for more HP than it costs to cast the healing spell. Kill them quickly!
• Heroes of Newerth: the Electrician's Electric Shield converts some of his mana into a shield that redirects half the damage he takes to it while also giving him a damage over time aura.
• Kingdom of Loathing has the Warbear energy bracers accessory, which lets monster attacks reduce your MP instead of your HP.
• In League of Legends Blitzcrank has an unusual variant. When reduced to low health he gains a shield that absorbs damage equal to a percentage of his current mana. Rather than draining mana it's limited by a cooldown.
  • Seraph's Embrace consumes a portion of the user's mana to gain a shield equal to the consumed mana for a short duration.
• The Wraith Armor in Blood Omen: Legacy of Kain.
• The Legend of Zelda:
  • The Legend of Zelda: A Link to the Past: Link can use the Cane of Byrna or the Magic Cape to become invulnerable to damage, but it will quickly drain his Magic Meter.
  • The Magic Armor in The Legend of Zelda: Twilight Princess is a variation- it diverts damage to your money supply while also draining it at a steady pace to fuel its effects (as there is no Mana Meter in Twilight Princess).
• Mabinogi has a skill by the same name as the trope, which uses a rather intricate formula for determining the damage hit to the user's Mana and also steadily drains it while in use. When their Mana does run out, any damage not blocked averts this trope. However, a recent Music-type skill subverts this trope, which regenerates quite a chunk of Mana such that it completely overrides the passive drain effect.
• Magical Girl Lyrical Nanoha A's Portable:
  • In The Battle of Aces, any attack that hits your barrier takes away from mana and being drained of all mana while guarding causes a guard crush with stun until the mana automatically regenerates.
  • The Gears of Destiny grants this to System U-D in her Final Boss form. As long as it's up, only throws or a Full Drive Burst could damage her Hit Points and she's Immune to Flinching. Combine this with tons of painful attacks, and you have a recipe for an SNK Boss.
• One of Gideon Jura's signature spells in Magic: The Gathering is a defensive shield that can stop just about anything, but each hit depletes his mana to sustain it.
• In MapleStory, all of the mage-type classes have a skill (commonly referred to as Magic Guard) that converts damage received to MP instead of HP, although it only absorbs up to 80% of the full damage. Still very important for mages to master, since they boast the highest amount of MP in the game out of any class, on top of potentially getting one-hit KO'ed by literally anything at the higher levels without it.
• The "Lightning Armor" Aeion ability in Metroid: Samus Returns depletes Samus' Aeion energy whenever she would normally sustain damage. It's used normally to avoid damage from certain hazards, but it can save her from a deadly attack in a pinch. Aeion energy in this game does not recharge outside of pickups from enemies. In Metroid Dread, Raven Beak has this ability, and an advanced version that can fully negate damage unless he's Melee Countered.
• Advocates in Nexus Clash get Inviolate Form, a power which forces attacks to mow through their magic points before their hit points. This synchronizes well with a whole lot of skills that can be combined to make Advocates into formidable tanks rather than the rather delicate angelic healers they initially appear to be.
• Oracle of Tao has a variant. Yazim Jianne, the hero that can use this can't actually use it to defend against attacks, but rather it heals him after the fact by shifting massive amounts of mana over to health.
• In OMORI, any character inflicted with the Sad emotion will have a portion of the damage they take dealt to Juice instead of health. Higher tiers of Sad (Depressed/Miserable) convert more damage to Juice. Note that being Sad also comes with a defense boost, making Sad characters much tankier than usual.
• Path of Exile mostly instead uses an Energy Shield that's fueled by the same primary attribute as your Mana (Intelligence), but doesn't directly interact with it. However, the Mind Over Matter passive causes 30% of the damage dealt to life to be redirected to mana instead, as well as a few items with similar effects. There's also The Agnostic passive, which rapidly consumes your mana to regenerate life if you're damaged. There's also an inverted version, Eldritch Battery where your shield protects your mana instead, allowing you to keep casting using your energy shield. These two can be combined, so 30% of damage goes to the energy shield that is effectively your mana (this may seem like an overcomplicated way of getting energy shield to protect the player's health, the thing it does already, but it's often mechanically superior).
• Prayer of the Faithless: The amount of Stamina available when an attack is taken affects how much damage is dealt. More Stamina, less damage.
• Puzzle Quest and its sequel have skills for magic-user characters that let you take damage from one of your mana pools in place of your HP. There's usually an upkeep cost for using them, so the duration of the spell is typically how long you can keep chaining mana to keep the shield going.
• Rondo of Swords: The Wyrm Medal protects from all damage by causing incoming attacks to deplete the MP gauge instead. Mephreyu uses it in his boss battle for either path but it will become yours once you slay him. There is also a skill named Mana Shield, but it reduces damage from all spells for one turn.
• While characters in Star Ocean: Till the End of Time can deal both standard HP damage and MP damage, the Convert Damage skill allows you to either do this or its inversion, converting MP damage into HP damage. Use of this skill can make Nel and Maria into better tanks than Fayt or Cliff.^note With Convert Damage: Preserve HP, 7 HP damage is converted into 1 MP damage, and while Cliff can easily reach 99,999 HP, Maria can reach 50,000 MP and Nel can reach 35,000 MP, giving them roughly twice the staying power.
• In Super Robot Wars, barrier abilities reduce damage while draining energy.
• Flynn from Tales of Vesperia can have a rather overpowered version of this, where as long as he has TP remaining, the damage of any attacks that strike him will be reduced by around 75%, while reducing TP by a very small amount for each hit taken.
• Tales of Maj'Eyal actually inverted this trope up until version 1.6. Archmages can get a shield that converts incoming damage to a mana increase. The downside is that, if the damage would bring your mana above its maximum value, your shield explodes instead. As of 1.6, this shield instead adds a passive barrier to your character when out of combat, then goes on to play this trope straight when damage would be done to hit points.
  • The solipsist has a more traditional version of this: A certain percentage of incoming damage is dealt to PSI instead of health. Note that the solipsist has less health than the squishiest of wizards, so this is a useful skill to have.
• This is more or less how blocking works in the Touhou fighters. You take no or reduced damage and can't die, but most attacks cause damage to the spirit gauge (necessary for danmaku and special) instead.
• Warframe gives players the option to do this with the mod Quick Thinking. Whenever your health would be depleted, it gets reduced to 2 instead, and the remaining damage is deducted from your energy instead. However, you do get hit with a nasty stagger effect, which can send you into a Cycle of Hurting, so it's better used as an emergency safety net rather than a way to let the squishy casters face-tank everything. For a short while, it was an absolute Game-Breaker when used in conjunction with Rage, a mod that restores energy when you take damage to your health, but it got patched out rather quickly.
• Warcraft:
  • In Warcraft III, this is one of the Naga Sea Witch's abilities.
  • Mages in World of Warcraft used to have Mana Shield, which caused damage to briefly be dealt to your Mana instead of your Health. Unlike healers' spells and other mage absorption spells, it didn't become more efficient as you gained more Spell Power from gear; but unlike them, it didn't cost any mana if it expired unused. It was later replaced with Incanter's Ward, which is similar but has a much shorter duration and actually restores mana per damage blocked instead of draining it.
  • Lady Deathwhisper casts one of these at the start of the fight, and doesn't drop it until her mana has been entirely depleted. Not that it stops her from casting spells after anyway.
• In Ys II: Ancient Ys Vanished – The Final Chapter the Goddesses give Adol the Shield Magic, which directs any damage he receives into his MP, just prior to the Final Boss battle. It drains MP on its own rather quickly though.

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