Rune Blade

Sword effective against spellcasting foes.
Damage 18
Crit 14%
Hit +15%
Effective Against Spellcaster
Value 2,500 gil (2,500 gil on Easy)
Found In Temple of Chaos

Equipped By

The Rune Blade is statistically identical to the Werebane, also found in the Temple of Chaos, except that a Thief can only use the Rune Blade. It will be a while before you run into any Spellcasters, but this sword stands well on its own merits. (At least, unless you bought a Mythril Sword in Elfheim, in which case this sword is useful for your Thief for about ten minutes until you pick up the Wyrmkiller.) Remember this sword when you fight the Evil Eye and Ogre Mages later in the game.
Compare Rune Blade to other Weapons
Treasures: Containing Rune Blade – 1 shown
Map
The specifics of where this treasure can be found
Notes
Temple of Chaos Found in a chest in the southeast treasure room (guarded)
Werebane Power Staff

Related

Rune Sword

Sprite
Damage 18
Crit 14%
Hit +15%
Val. 2,500 G

Equipped By

Found In Temple of Fiends
The Rune Sword is nearly identical to the Were Sword, also found in the Temple of Fiends, except that a THIEF can only use the Rune Sword—and it looks much cooler. It's not a bad sword, except in comparison to the Silver Sword in ElfLand. It has a slightly higher crit rate than the Were Sword, making it arguably the most effective of the three mystic KEY-locked specialty swords for a FIGHTER.

Rune Blade

Sprite
Attack +4
Type Greatsword
No. 28 Game FFI
Dropped By Golbez
This blade's engravings conjure foreboding imagery of retribution and reckoning.

Rune Edge

Sprite
Consumes MP to inflict mortal blow
Type
Icon
Sword
Special Properties MP Critical
Price 7,500 GP
Value 3,750 GP
Bat.Pwr 55 Hit Rate 150
Evade % 10 (not used) MBlock% 0
Used With SwdTech, Runic, 2-hand, Throw

Equipped By

Terra
Locke
Cyan
Shadow
Edgar
Sabin
Celes
Strago
Relm
Setzer
Mog
Gau
Gogo
Umaro
Merit Award
World of Ruin Shops Nikeah
Found In Narshe Moogle Lair
The Rune Edge is the first weapon you're likely to find with the MP Critical ability. This costs the wielder 12–19 MP per hit, but guarantees a critical (and 50% extra damage) if the MP is spent. The Rune Edge is a bit weak, and MP totals too low, to be that useful when you find it.