Reduced Mana Cost

In RPGs with a Mana Meter, it is possible that they may have an item (usually an accessory) that reduces the cost of the wearer's skills, usually by half, effectively doubling the caster's mana pool. This may or may not become a Game Breaker, usually dependent on how powerful spells are in the game.

An inversion is something that increases skill cost, but usually adds other effects, such as increased damage.


 * In Digimon World, you may get an "MP Consumption Bonus" after finishing a battle, which reduces the amount of MP required to use attacks. At least, that's what it does in the PAL versions - getting this bonus in the NTSC versions usually results in nothing more than your game crashing on the spot.
 * The Final Fantasy games love these. Every game after III has an accessory that halves MP cost, usually called the "Gold Hairpin". In Final Fantasy VI, there's an accessory that reduces it to one (and, once you have Ultima, it becomes ridiculously game breaking). Final Fantasy X also does this.
 * Final Fantasy X 2 has the Soul of Thamasa, which doubles the cost of spells and increases the damage they inflict, and the Ragnarok, which makes any skill or spell cost 0MP. They are practically a Game Breaker when equipped on the same character.
 * Final Fantasy VII Crisis Core has many items that do this like the Soul of Thamasa which reduces all MP costs to 0. The Genji helm also does this and while it is useful, it is not as useful sometimes as say the Ziedrich, an item that increases all stats by 100.
 * Final Fantasy VIII and Final Fantasy XIII, lacking traditional MP, has other ways to accomplish this. VIII has the "Expend2x1" and "Expend3x1" that allow you to cast two or three times at the expense of one spell stock. XIII has various weapon modifications that charge your ATB rate, effectively allowing you to cast faster.
 * While Final Fantasy XI lacks a straight example of this trope, as everyone would be required to have one and therefore no one could afford one, some pieces of mage gear have a degree of the Conserve MP trait, which confers a small chance of halving the MP spent on a spell.
 * The Lord-Sorcerer's Gown in Last Scenario halves all mana costs. Also inverted with the Spellcard Mod, which doubles MP cost but multiplies damage by 1.5.
 * Tales of Phantasia has three types of rings that reduce TP cost by 1/3, 1/2, and 2/3.
 * Tales of Vesperia has rings that reduce TP costs by amounts similar to the Phantasia example, but also has a notable Game Breaker in the form of the Risky Ring, which reduces TP costs to 1 at the minimal cost of significantly reduced defenses. Defense isn't an issue when artes can be spammed constantly, thus preventing oneself from getting hit in the first place, though.
 * Chrono Trigger has not only the Silver Stud, which cuts MP cost by half, but the Gold Stud, which cuts it to 25%. The latter is a serious Game Breaker thanks to the Black Omen, from which you can farm enough to supply your entire roster.
 * Advanced magic in Chrono Trigger is incredibly powerful but balanced by its extremely high MP cost, making Golden Studs a complete Game Breaker. Luminare won't outright kill most enemies, but two uses will, and three uses will make bosses cringe.
 * Lots of items in Mario & Luigi: Bowser's Inside Story: The Budget Charm, the Thrift Charm, the Tight Belt, the Economy Ring and the Cheap Ring. Inverted with the Luxury Patch and Heroic Patch, which raise SP cost in return for added power for the attacks as does the Heroic Ring. Some even auto restore the amount once per turn.
 * A Link to The Past gives you the option of halving the cost of all magic items.
 * Super Mario RPG has an accessory that cuts Flower Point costs in half.
 * Conserve Power from City of Heroes.
 * Several powers will reduce endurance cost, or grant so much endurance recovery that you can spam costly powers without tiring out (Speed Boost, I choose you!) Electric attacks have a chance of restoring the endurance you used back, essentially giving you an attack at no cost.
 * The level 20 power in the Fitness power pool (which is available to everyone) adds a bonus to endurance restoration. Properly slotting it, and combining it with an endurance reduction ability, means the only thing stopping you from spamming your strongest powers is the cooldown on the powers themselves. And since there's a corresponding power to reduce cooldown times...
 * Jays Journey has the Gold Hairpin. Like in Final Fantasy, (which it's probably a Shout-Out to) it halves MP cost.
 * The second and third Disgaea games play this straight and invert it. The all-female Mage class can cast spells with less SP than any other character in the game, while the all-male Skulls require 50% more SP to use their spells, but they hit harder. Then again, considering how ridiculous the stats can get, it's pretty much impossible to run out of SP in the endgame, no matter how many level 100 spells and skills you spam.
 * Sufficient skill with a spell GURPS lets you cut its cost by a point of energy every few levels. With enough skill a casting may cost nothing at all.
 * Numerous examples exist in Magic the Gathering, ranging from completely useless to potentially gamebreaking.
 * Inverted in World of Warcraft, the curse of Lucifron makes every ability cost double its initial cost, and even works on the Death Knight class which uses "Runes", which wasn't invented when Lucifron was made.
 * Discipline Priests have a straight example with Power Infusion, reducing mana costs of the target.The amount of talents available to classes with similiar effects are too numerous to mention.
 * Shin Megami Tensei Devil Survivor has a skill called Magical Yang that halves MP costs for both the user's party and the enemy party they're currently fighting against, and inverts it with Magical Yin that makes the spells cost double the MP but giving them a 50% power boost. Despite the lack of any MP-restoring items, the latter is a far better option most of the time thanks to the Mana Drain spell's effectiveness in both crippling the enemies and giving their MP to you and because of a racial skill that restores a set amount of MP to all your characters after combat depending on how much damage you do to your enemies.
 * The Persona series has Spell Master, which cuts that Persona's MP costs in half. Very dangerous if you fuse it onto something like Satan (Black Viper) or Helel (Morning Star). Flat out broken when you combine Victory Cry (restore all HP/MP post combat) and Alpha and Omega/Armageddon (instantly kill anything short of the bonus boss, 100% of the time but costs 100% of MP).
 * In Heroes of Might and Magic 5 heroes can learn a skill "Arcane Training" to permanently cut the mana cost of all his spells by 20% and then another one, "Erratic Mana", to randomly cut the cost of each cast cast by up to 50% more.
 * Mage units also reduce the costs of their masters spells by 25% and the Week of Might and Magic halves mana costs for everyone.
 * The "Pressure" ability from the Pokémon series is an inversion of sorts - the ability doubles the PP consumption for any Pokemon engaged against the ability's user. Irritatingly, it's on too many Legendaries to keep track of, the few known exceptions including, but not limited to, the Weather Trio (Groudon, Kyogre, Rayquaza) and the Isshu Pair (Reshiram and Zekrom do not have it).
 * Kingdom of Loathing has a few of these, including a recurring in-game holiday. Most of them will only stack to -3 MP per casting. A few do ignore that limit, including the aforementioned holiday, so you could theoretically get a reduction of 9 MP off every skill you cast, or 14 if you're a Pastamancer. This would be a Game Breaker if the most useful non-combat skills weren't also limited to a certain number of uses per day.
 * A Psionic in Dungeons and Dragons 3rd edition could purchase a Torc of Power Preservation to get this effect. While the actual amount of PP (mana) preserved was only 1 point, it could easily extend your pool of mana immensely (as you can manifest numerous powers each day in the mid-to-high levels). There are feats and prestige classes that have similar effects (major examples include the Anarchic Initiate PrC and the Midnight Augmentation feat). And the Wilder base class has one of these built in (but it has... issues).
 * Deus Ex has the Power Recirculator, which reduces augmentation energy use by 10%-60% for a piddling 10 units/minute.
 * The equivalent in Dungeons and Dragons third edition, a few prestige classes reduce or nullify the cost of "metamagic", i.e. a way to make your spells stronger. The effect is that you can make all your spells stronger at no added cost; this is very much a Game Breaker.
 * In Terraria, wearing the entire set of Jungle Armor will reduce the mana cost of all magic items by 16%. This stacks with the Nature's Gift accessory, which reduces mana costs by 6%.
 * In addition, the Space Gun uses mana instead of ammo, unless you're wearing the full set of Meteor Armor, in which case the gun uses neither ammo nor mana. The gun makes for quite an efficient long-range weapon, so even though there are higher-tier armors than the Meteor Armor, you might find it worthwhile to stick with it.
 * In Rune Factory 3, the Fluffy Scarf accessory cuts Rune Point use to zero for most activities.