The Mage's Habit is a mid-ranked mystic headgear in Final Fantasy XII that boosts the wearer's Defense by 21, Magick Power by 6, and MP by 50 (Zodiac) or 10 (original).
The Mage's Habit is sold for 2,500 gil Jahara after visiting Eruyt Village, and in Rabanastre after defeating Judge Bergan. It also very rarely drops from the Battery Mimic, the enemies that eat the electricity in the Barheim Passage, allowing it to be potentially obtained much earlier than from the shops.
The Mage's Habit is sold for 2,500 gil in Eruyt Village and Mt Bur-Omisace. It is found as a treasure in Henne Mines' Phase 1 Dig (75% chance to appear, 60% chance for gil, 50% chance the item treasure is the Mage's Habit without the Diamond Armlet equipped), and Paramina Rift's Freezing Gorge (70% chance to appear, 35% chance for gil, 50% chance the item treasure is the Mage's Habit without the Diamond Armlet equipped), as well as in the Trial Mode Stage 65 with the Diamond Armlet equipped. It still very rarely drops from the Battery Mimic.
The Mage's Habit is a mid-ranked mystic hat, giving 21 or 18 Defense depending on version, and 5 Magick Power, as well as 50 or 10 MP depending on version. Mystic armor offer magick-related bonuses that affect all types of magickal actions, from casting black magick to damage an enemy, to casting white magick to heal the party. Magick Power is also a factor when determining damage dealt by katana, staves, and maces.
In the Zodiac versions, White Mage, Red Battlemage, Black Mage, and Bushi can equip it, and so the Mage's Habit is only useful to buy if the player has chosen any of these License Boards for their party. In The Zodiac Age versions, after fighting Belias the player can choose two License Boards per party member; it is usually a good idea to pair jobs that use two different types of armor for versatility.
Mage's Habit can be obtained unusually early, allowing the player to skip buying all the lower-ranking mystic armors, as a very rare (1%) drop from the Battery Mimics in the Barheim Passage during the segment where Basch is a guest. Afterward, the player cannot return here or fight more Battery Mimics elsewhere.