Sage's Surplice

Sage's Surplice, also known as Sage Robe, Sage's Robe, Wizard's Robes, or Wizard Robe, is a recurring armor in the series. It is usually a high-rank robe, only be outmatched by White Robe, Black Robe, and Robe of Lords oftentimes. It provides high defense and sometimes Magic as well. It is mainly usable by the mage classes.

Final Fantasy
Sage's Surplice is the 3rd best armor in the game, being beaten out by Light Robe and Gaia Gear. It is usable by all mage classes, and provides +25 Defense, +2 Weight, and +5 Intelligence. It is only available in the 20th Anniversary version, and can only be found in Lifespring Grotto.

Final Fantasy IV
Sage's Surplice, originally known as Wizard Robe in the SNES version, is a mid-rank robe and is only equippable by the mages. One can found in the Tower of Zot, while additional others can be bought at the Dwarven Castle. It provides +5 Defense, Magic Defense, Magic Evasion, and Spirit.

Final Fantasy V
Sage's Surplice is a low-rank armor, and is only usable by magic-based jobs. It can be bought in Jachol and Crescent, and provides +6 Defense, +8 Magic Defense, +17 Magic Evasion, and immunity to Silence.

Final Fantasy XII
Wizard's Robes is a low-rank armor that can be bought for 1000 Gil and requires 20 LP to use. It provides +5 MP, +12 Defense, and +4 Magic.

Final Fantasy Tactics
The Sage's Robe is the best robe in the game, and is only available through Multiplayer Mode. It provides +120 HP, +100 MP, and halves all elemental damage. The weaker Wizard's Robes is a low-rank robe that costs 4000 Gil to buy, and provides +30 HP, +22 MP, and +2 Magic.

Final Fantasy Tactics Advance
Sage Robe is a high-rank robe that teaches the ability Geomancy. It provides +24 Weapon Defense and +52 Magic Resistance.

Final Fantasy Tactics A2: Grimoire of the Rift
Sage's Robe is again a high-rank robe that teaches the ability Geomancy. It provides +26 Defense and +62 Resistance.

Final Fantasy Crystal Chronicles: Ring of Fates
Sage's Robe is a mid-rank armor that requires the Enchanted Cloak scroll. It provides +76 Defense and +15 Magic. The weaker Wizard Robe requires the Hellish Raiment scroll, and provides +60 Defense and +17 Magic.