Dualcast

Dualcast (連続魔), also known as X-Magic, Redx2, W-Magic (Ｗまほう), Doublecast, and Double (ダブル), is a recurring ability which allows a character to cast two spells in one turn.

Final Fantasy IV
Dualcast is an augment ability in the Nintendo DS version. It is obtained by speaking with the Mysidian Elder if the player gave three augment abilities to Palom and Porom before they leave the party, with each twin having at least one ability each. Dualcast is compatible with Black and White Magic, but not with Summon Magic.

Final Fantasy IV: The After Years
The ability Dualcast can be extracted from the Dark Crystal on the 15th floor of the Depths. The ability is acquired by defeating the optional boss Deathgaze, and can only be learned by Palom, Porom, or Leonora.

Final Fantasy V
Dualcast is the Red Mage's level 4 ability. Dualcast notably works with most types of magic, even Summon Magic. The only exception is Blue Magic. However, these magic types must still be equipped to be used with Dualcast. Because it is a form of Red Magic, Dualcast on its own gives access to the first three levels of White and Black magic spells without the character having any other magic types equipped. It is also one of two abilities that costs 999 ABP to learn, the other being Mimic.

Dualcast is affected by the "Mix and X-Magic Glitch."

Final Fantasy VI
Dualcast, also known as X-Magic, can be used if a character is equipped with the Soul of Thamasa relic. The only drawback is that the character cannot summon the esper he or she currently has equipped.

Final Fantasy VII
The W-Magic Materia allows a character to cast two spells in one turn. The somewhat similar Quadra Magic lets the linked Magic or Summon Materia be cast four times for the cost of one casting.

Crisis Core -Final Fantasy VII-
Dualcast is a Support Materia Zack Fair can either buy from the Network Shop Shade or find in a chest during mission 9-1-4. When any Magic Materia is used while Dualcast is equipped, it is cast twice in succession.

Final Fantasy VIII
Double (ダブル, Daburu) and Triple (トリプル, Toripuru) are spells usable by the player, and by some enemies. The Double spell inflicts the status effect of the same name, while Triple inflicts the Triple status. Unlike other positive statuses in the game, Double and Triple have no time limit and last till the end of the battle once inflicted. When under Double or Triple status, a character may cast a spell two or three times at once, at the cost of expending more spells from their stock than normal. Cerberus casts both on the party when summoned. Some Guardian Forces have the abilities Expend x2-1 or Expend x3-1 that only removes one spell from the caster's stock when Double or Triple are used.

Double is a fairly common spell in the early stage of the game, but it can be drawn from very few normal enemies. Casting Double in battle increases compatibility with Carbuncle by 1 and with Cerberus by 0.8, but lowers compatibility with Eden by 0.2.

Triple is one of the rarest spells in the game and can only be drawn from bosses. It is one of the most powerful junctioning spells in the game, second only to Ultima. The Quistis and Irvine cards can be converted into Samantha Souls and Rocket Engines, respectively, and then into Triple spells; these cards, along with any other unique card other than PuPu can be won back from the 'CC' Card Club group during Disc 4.

Casting Triple in battle increases compatibility with Cerberus by 2 and with Carbuncle by 1, but lowers compatibility with Eden by 0.2.

Final Fantasy IX
Vivi's Trance ability is Double Black, letting him take two rapid turns to cast two Black Magic spells. Eiko's Trance is Double White, allowing her to similarly cast two White Magic spells. Occasionally, enemies can take turns in between the first and second cast.

Final Fantasy X
Doublecast allows a character to cast two Black Magic spells in a row. It is located in Lulu's section of the Sphere Grid, but several locks must be passed first. Lulu's Overdrive, Fury, allows several successive spells of one type to be cast. Seymour Guado has the ability to double-cast or quadruple-cast the same elemental spell in certain battles against him.

Final Fantasy XII
Chain Magick is an enemy-exclusive ability. Upon casting it will grant the user zero charge time of any subsequent spell casting. However, one must wait for the action animation ends before proceeding the next action, this can be further prolonged when the effect capacity is saturated.

Final Fantasy XIII
Dualcasting is a Paradigm consisting of two Ravagers.

Final Fantasy XIV
Originally Conjurers were able to use Chainspell before casting a spell to remove its casting delay and recast cooldown. This ability was removed with the reform of class actions, but returned as a White Mage ability called Presence of Mind. Ironically the closest class to a Red Mage is a Thaumaturge with the healing spells of a Conjurer set, but it is unable to use Presence of Mind.

Final Fantasy Tactics Advance
Doublecast is learned by Red Mages via the Madu. When used, it allows the unit to cast two spells from both of the A-Ability sets if possible. Doublecast works with White, Black, Summon, Spirit Magic, as well as certain Corner abilities. Doublecast can also be used to avoid some elemental, skillset, and Dmg2 laws because Doublecast is seen by the game as a non-aggressive, non-elemental, Red Magic ability. It is also one of few abilities in Final Fantasy Tactics Advance to cost 999 AP to master.

Final Fantasy Tactics A2: Grimoire of the Rift
Doublecast is again learned by the Red Mage for 990 AP via the Madu rapier. The game mechanics for it have changed, though; it is more sensitive to laws than its incarnation in Final Fantasy Tactics Advance. Though specific skillset laws have been abolished, the spells used in Doublecast will be sensitive to elemental laws.

Final Fantasy Type-0
In this game, Doublecast is defined by the ability of equipping two magical attacks to one character. Rem Tokimiya is credited for having this ability by default but it can be learned by other characters during the game.

Final Fantasy: The 4 Heroes of Light
The Sage's Spell Again ability lets the character continuously cast the spells they have equipped until they run out of AP.

Dissidia Final Fantasy
Terra's EX Mode bonus Chainspell allows her to use her magical attacks twice in succession.

Dissidia 012 Final Fantasy
Terra's ability "Chainspell" returns as her ability in EX Mode as well as Regen, Critical Boost and Glide.