Rune

A rune is a special kind of upgrade item that is applied to a character's armor. Runes are most often obtained by using an Expert Salvage Kit on the armors that drop from monsters, such as Ettin's Pauldron or Seeker's Armor. Only a certain level of item rarity can have a rune. To view the runes your class can use, see out Rune Listing page.

Types of Runes
Runes come in 3 types:

Minor Runes provide minor bonus to the named statistic.

Major Runes provide a larger bonus to the named statistic.

Superior Runes provide an even larger bonus to the named statistic.

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 any armor at a time.

Stacking
Runes affecting the same stat do not stack. Ergo, you can only receive one benefit from any particular line of runes. Example:

A Minor Rune of Vigor adds +20 Health. If you attach this to your chest armor, and a second Minor Rune of Vigor to your head armor, you will still only have +20 health. If you attach a Major Rune of Vigor to your hand armor, you'll gain a total of +30 health; the two minor runes will effectively be overwritten by the higher-quality rune.

Recovery
You can use an Expert Salvage Kit on armor that you've placed a rune on to (probably) recover the rune. Bear in mind, however, that this only works for armor that has been crafted by an NPC; items gained from a collector NPC can never be salvaged, and so you can't recover runes from those items.