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.