Do runes stack?

So what is the max bonus i can have? Can i have 5xSuperior rune and have +15 bonus or?

Thank you very much.

no. runes don't stack

you can have one type of rune per outfit. So you can say have one superior rune for a +3 bonus, but any other of the same type of run just disappears

That said, you can have multiple runes of different types, so you can have a fire rune, a vigor rune and a water rune on an outfit, each giving you a seperate bonus.

Also, when you buy an armor that has +1 of any one of your skills, you can use only one minor, major, or superior rune to have the same bonus as the +1 armor. For example, let say you're a Mesmer, your mask have +1 illusion, chest have minor illusion rune, gloves have minor illusion rune, leggings have vigor rune. You'll think, "oh, I have 3 illusion bonuses with +1 effect, so therefore I will have +3 for illusion skill." Wrong. You'll only have +2 bonus for illusion. The other minor illusion rune will not stack. If it was a major or superior illusion, that will replace the minor.