Cuts MP use by half in battle.
Description
Half MP is a support ability in Final Fantasy IX for mages that halves all MP costs during battle. Half MP costs 11 Magic Stones to activate.
Obtained[]
Half MP is learned from Light Robe and Protect Ring for variable amounts of AP; Quina learns it the fastest at 90 AP where Vivi takes the longest at 140 AP. Wearing both equipment pieces at the same time masters the ability at double the pace.
Light Robe is first found in the Ocean chocograph after the party has Blue Narciss, stolen from Kuja, and synthesized in the endgame in Black Mage Village.
Protect Ring is found from using a Dead Pepper at mountain crack on eastern part of Lost Continent while riding Choco 
as soon as the player has the Blue Narciss and has advanced in the Chocobo Hot and Cold game far enough to have Dead Peppers available. The other ways to get the Protect Ring are in the endgame, or from excess playing of Chocobo Hot and Cold and then buying it from Mene.
Mechanics[]
With Half MP equipped, the character's MP costs are halved in battle. In the menu, the spells that can be used outside of battle still cost their base MP rates.
The chance of getting a long summon animation depends on the caster's MP and the cost to summon the eidolon; Half MP has no effect on this calculation.
Use[]
Half MP is excellent for every mage character, making Vivi's top tier spells, Quina's Mighty Guard, and Dagger and Eiko's eidolons more readily usable. It is a good idea to keep Half MP equipped at all times after learning it, though Vivi can also support himself with Osmose and Amarant can support mages with Chakra. Another good way to restore MP is to use Ethers in battle with Chemist. Half MP ensures that the player does not need to use up a turn mid-battle for MP restoration as often, especially useful for boss battles.