Guild Wars 2

The sigil I am talking about: https://wiki.guildwars2.com/wiki/Superior_Sigil_of_Concentration

So if I have 100% boon duration already and I swap to this weapon will the 33% longer for 7 seconds still work? Meaning over 100% duration in a way?

Sorry if that is confusing, a friend brought it up and now I’m worried I’ve wasted an expensive sigil..

No it won’t do anything if you already have 100%.

Why not? 100% duration doesn’t mean permanent duration it means twice as long. So 133% is twice plus a third

Because 100% is the cap.