Rune

A rune is a kind of upgrade item that is applied to a character's armor.

Availability
Runes can be obtained by using an Expert Salvage Kit or Superior Salvage Kit on Salvage Items such as Ettin's Pauldrons or Seeker's Vests. Only a non-white salvage item can have a rune. A blue salvage item will always have a minor rune. A purple salvage item will have a high probability of either a minor rune or a major rune and a lower chance on a superior. A gold salvage item will always have either a major rune or a superior rune. If you salvage the salvage item before identifying it, you will receive an unidentified rune.

Runes are also available for purchase from rune traders in cities. Since you are not identifying the rune if you buy it from a trader, you do not unlock the rune for PvP.

You can also unlock runes at a Priest of Balthazar. This only unlocks the rune for PvP and does not put one into your inventory.

Use
To use a rune, double-click it and then click on the piece of armor you want to apply it to. Only one rune can be placed on a single piece of armor at a time. If you apply a rune to a piece of armor that already has one, it will replace the old rune (after asking you to confirm the replacement). You can only use runes linked to your primary profession (or the generic runes of Vigor). For example, a Monk/Ranger could not use a rune of Minor Marksmanship, while a Ranger/Monk could.

Stacking
Vigor runes, absorption runes, and runes affecting the same attribute do not stack within their own type. You can only receive the benefit of the highest potency rune from each. However, health penalties from all attached runes will stack.

Example: A Rune of Minor Vigor adds +30 Health. If you attach one to your chest armor and another to your head armor, you will only gain a bonus of +30 health. If you then attach a Rune of Major Vigor to your hand armor, you will only gain a bonus of +41 health; the two minor runes will effectively be overridden by the higher-potency rune.

Headgear that provides +1 to attributes does stack with runes. For example, a Wicked Scar Pattern (+1 Curses) with a Superior Rune of Curses applied to it would add a total of +4 to your Curses attribute. Note that absorption runes stack with the effects of Knight's Armor or Ascalon Armor.

Recovery
You can use an Expert Salvage Kit on armor that you have attached a rune to in order to attempt to recover the rune. This will destroy the armor and either recover the rune or salvage materials.