The Grand Armor is the ultimate heavy armor in Final Fantasy XII that boosts the wearer's Defense by 67 (Zodiac) or 61 (original), and Strength by 12. The Grand Armor is metallic for the purposes of the magnetize debuff present during the Vinuskar (though the helm is available after this boss) and Ultima boss battles.
The Grand Armor is difficult to procure in the original version, where the player may opt to not bother upgrading from the preceding Maximillian, which is much more readily available. In the Zodiac versions, there are more ways to obtain it, making Grand Armor a good contender for an endgame armor.
In the PlayStation 2 version, the Grand Armor drops from the Helvinek. The chance of getting it is 3%, 6%, 9%, or 12%, depending on the player's chain level. The best way to acquire one is by chaining Helvinek using the zone out glitch; when the Helvinek appears, the player must lure it to an area zone line, defeat it, grab the loot and get into the next zone before the EXP and LP are displayed, and it will reappear in the next zone. One has to be quick, so if the loot is too far away, the player should just leave the loot and fight it again in the next zone.
In the updated Zodiac versions, the Grand Armor is still the rare very drop from the Helvinek, and the same chaining trick works, but there is now a less arduous way to procure it: the Grand Armor is found as a treasure in Henne Mines' Special Charter Shaft (25% chance to appear, but is always the Grand Armor). It is also found in Cerobi Steppe's The Northsward (10% chance to appear, 80% chance for gil, 5% chance the item treasure is the Grand Armor with the Diamond Armlet equipped).
The Grand Armor is available in the Hunt Club on the Phon Coast by giving Blok all the 30 Rare Game trophies, which makes the helm available from the Shifty-Eyed Merchant's store nearby for 162,000 gil.
Grand Armor is the ultimate armor giving 67 or 61 Defense depending on version and 12 Strength. The strength bonuses make heavy armor ideal for frontline fighters, and the Grand Armor is a good armor to equip on anyone who attacks physically, although a gun-wielder does not benefit from the strength-boost. In the Zodiac versions, Uhlan, Knight, Time Battlemage, and Foebreaker can equip it natively, and Archer can unlock it with Shemhazai. Grand Armor is only useful to obtain if the player has chosen these License Boards for the party. In The Zodiac Age versions, after fighting Belias the player can choose two License Boards per party member and so more characters can benefit from heavy armor, as it is usually a good idea to match jobs that use different types of armor to bolster light armor jobs' strength, and to give more durability to spellcasters.