Rune equipment

Rune Equipment is a recurring type of equipment in the series. In most games that it appears in, it is usually one of the stronger type of equipment, though some Rune equipment can be found mid-game. Most Rune equipment either deal with using MP for automatic critical hits or dealing extra damage to Mage-type enemies. The most common recurring type of Rune equipment are the Rune Blade, Rune Axe, and Rune Staff.

Final Fantasy
The Rune Blade was originally the only Rune equipment in the game, until the Dawn of Souls remake where the Rune Staff and Rune Axe appear as well. The Rune Axe is capable of casting Curaga when used as an item, while the Rune Staff could cast Healara when used as an item. The Rune Blade simply did extra damage to Mages.

Final Fantasy II
The Rune Axe deals extra damage against Mages and also casts Fog when used as an item, and is also the 2nd strongest axe in the game. It is the only Rune equipment in the game.

Final Fantasy III
The Rune Staff is a high level staff that can cast Erase. The Rune Bow is a mid-level bow while the Rune Axe is a mid-level axe that both provides +2 Intelligence and Mind. The Rune Bell is the 2nd strongest Bell in the game. The Rune Bracers are the first armor type of the Rune Equipment, and is a mid-level armor that provides some resistance to status attacks.

Final Fantasy IV
The Rune Axe is the 2nd strongest axe in the game, and deals critical damage against mages. The Rune Staff also deals critical damage against mages, and can also inflict Silence when used as an item. Rune Armlet provides resistance to Silence, as well as being a mid-level armor

Final Fantasy V
The Rune Axe inflicts critical damage in exchange for MP, and is one of the Sealed Weapons. The Rune Chime also consumes MP for a critical hit, and is the 2nd strongest Bell in the game. Rune Edge is a mid-level sword that also consumes MP for a critical hit, though it is not found till late in the game.

Final Fantasy VI
The Rune Blade consumes 10 MP each attack for a critical hit, and can only be used by Terra, Edgar, and Celes.

Final Fantasy VII
The Rune Blade and Rune Armlet represents Rune Equipment in this game. Both pieces of Rune equipment have Double Materia growth abilities.

Final Fantasy VIII
Though it cannot be equipped, the Rune Armlet appears in the game as an item that can teach the ability "Spr +20%" to any GF.

Final Fantasy IX
The Rune Tooth is a mid-level weapon for Zidane that teaches him the ability "Lucky Seven", and has innate Poison. The Rune Blade is a high-level sword that only Steiner can equip that teaches him the ability "Iai Strike", and has innate Darkness. The Rune Claws are Amarant's strongest weapons that teaches him Spare Change, Demi Shock, and Revive, and also have innate Darkness.

Final Fantasy X
Several weapons can get the Rune moniker by having the ability "Magic +5%" as the dominant ability. Tidus can also get the weapon Runemaster by having all 4 "Magic +%" abilities on a weapon.

Final Fantasy X-2
The Rune Bracer is an accessory that double the wearer's max HP.

Final Fantasy XII
The Runeblade represents the Rune equipment.

Final Fantasy XII: Revenant Wings
The Runeblade appears again as a mid-level weapon for Vaan.

Final Fantasy Tactics
The Runeblade is a high-level sword, and is the only Rune Equipment in the game.