Artemicion said:
If I recall correctly the +number is % based. People usually get around +13-14 in additional effect augments and report that the proc rate is downright horrendous.
Fire Damage +13 will do exactly 13 fire damage additional effect I believe, the proc rate is reported to be about 10%, but there's a possibility (that I made up and has no basis on fact) that the proc rate is 13% perhaps?
Anyway, spamming too much, night y'all.