Hat that raises Spirit.Description
The Feather Hat is a light armor headgear in Final Fantasy IX. It is a weak hat that Zidane, Vivi, Dagger, Quina, Eiko, Cinna, Marcus, and Blank can wear, though Blank and Cinna are not in the party when the Feather Hat is available in a normal playthrough. Its notable trait is that it boosts the wearer's Spirit on level up, a generally useful stat to raise for any character. The Feather Hat teaches the passive abilities Add Status, which imparts a status ailment from the wearer's weapon onto their target, and Bright Eyes for Zidane that makes him immune to Darkness status. The Feather Hat boosts the wearer's Wind damage and is used for synthesis.
The Feather Hat provides 7 Magic Defense, minorly mitigating damage from magic attacks. It boosts the wearer's Wind damage by 50%, but the only abilities that can benefit from this are Dagger and Eiko's normal attack with rackets, Quina's Twister, and Fenrir's Millennial Decay.
The hat minorly boosts the wearer's Spirit when they level up with it equipped. When enough "bonuses" upon level up from gear have been gained, the character gains a permanent stat increase. Spirit is a generally useful stat to raise, affecting various gameplay mechanics: the HP gained when revived, the duration of expirable statuses, how often Regen ticks, how fast Trance builds or runs out when active, etc. The Feather Hat gives the smallest stat boost, meaning the character would need to level up multiple times with +1 Spirit gear for noticeable stat gain.
The Feather Hat is early game gear that may be useful to equip onto Zidane, Vivi, Dagger, or Quina during their adventures on the Mist Continent, though soon after Dali the player can get the stronger Steepled Hat, which also offers a stat boost. The Feather Hat teaches Add Status, a useful ability for everyone who can learn it, as well as Bright Eyes, a slightly less useful ability for Zidane as Darkness-protection is not among the most commonly needed immunity abilities in the game.
The Feather Hat's ability to boost Wind damage can be useful when Dagger equips a racket and the player uses her for physical damage. By the time Quina and Eiko can use their Wind attacks the player will be superior Wind-boosting equipment available, and wearing multiple Elem-Atk gear pieces concurrently does not stack the effect.
The Feather Hat is useful to buy from Dali to replace the party's Leather Hats for Zidane, Dagger, and Vivi to use in Dali Underground and in the boss battles that ensue when leaving Dali. Though it has a minor stat-boosting effect, the player does not need to min-max in a normal playthrough and can choose equipment based on the abilities they teach and their defensive offering. The best stat-boosting gear will be available late into the game, meaning the player would be optimized to limit their level ups until endgame for the best stat gains; therefore it is not particularly useful to level-grind with the Feather Hat equipped unless the player gets stuck in a tough encounter or dungeon.