Guild Wars 2

As the topic says,

20% chill duration runes… are they suppose to stack in duration,
If you used 2x from 3 different runes that would stack chill by 60%
combined with a sigil for another 10%… does this work or is it not intended?

Thanks

That’s how all condition duration runes function.

if these are the (2)boni from 3 different sets -yes.