Bubble (バブル, Baburu?) is a status effect introduced in Final Fantasy XII and is also the name of the Arcane Magick spell which causes said effect. The effect has also appeared in the DS version of Final Fantasy IV. The Bubble status doubles a party member's HP until the end of battle.
The Bubble status appears in the DS version of Final Fantasy IV and it is accessible either through Tellah's Recall ability or through Kain with Twincast when paired up with either Cecil or Rosa. It doubles the entire party's maximum HP.
While there is no Bubble status in Final Fantasy XI, the temporary item Giant's Drink can be used to raise the player's max HP by 100% for 15 minutes. This item is usually only found in large events such as Besieged or Campaign, where one would need the extra hit points to survive.
The character brims with life, doubling max HP. The effect is temporary.
Bubble is both a status effect and the Arcane Magick spell that causes it. Bubble doubles the maximum HP of the character it is cast upon. Unlike similar abilities from previous games (the Berserker's Howl in Final Fantasy X-2, for example) it also raises the current HP to reflect the new maximum limit. As an added effect, characters in Bubble status will be immune to Disease. In addition, if a character is already inflicted with Disease, Bubble will cure it.
Bubble Belts can be equipped to induce a permanent Bubble status. These can also be bought from the Clan Provisioner after achieving the rank of Riskbreaker (though it is unavailable while the Clan Rank is Paragon of Justice). One will also become available through the Bazaar, and Bubble Belt can also be randomly found in a respawning treasure in Barheim Passage's East-West Bypass, in the dead-end section, when the Diamond Armlet is equipped. The Bubble Belt is also a reward for the Antilon hunt.