The Topkapi Hat is a low-ranked mystic headgear in Final Fantasy XII that boosts the wearer's Magick Resist by 8 and Magick Power by 3, and in the Zodiac versions, MP by 20.
In the original PlayStation 2 version, the Topkapi Hat is sold for 500 gil in Rabanastre after leaving Barheim Passage, Bhujerba, Dreadnought Leviathan, Dalmasca Westersand after the Leviathan but before obtaining the Treaty-Blade, and in Nalbina Fortress. It also rarely drops from the Flan in the Barheim Passage.
In the updated Zodiac versions, the Topkapi Hat is sold for 500 gil in Bhujerba, in Rabanastre after meeting Ba'Gamnan in the Lhusu Mines, and on board Dreadnought Leviathan. It is found as a treasure in Lhusu Mines' Oltam Span (75% chance to appear, 40% chance for gil, 50% chance the item treasure is the Topkapi Hat without the Diamond Armlet equipped), as well as in the Trial Mode Stage 13 with the Diamond Armlet equipped. It still rarely drops from the Flan in the Barheim Passage.
The Topkapi Hat is a low ranked mystic hat, giving 8 Magick Resist and 3 Magick Power, as well as 20 MP in the Zodiac versions. 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 it is only useful to buy if the player has chosen any of these License Boards for their party's first jobs. The superior Calot Hat is available soon after the Topkapi Hat, and so the player may want to skip it in favor of it.