How does the effect on the rune "Relentless Convction" http://eq2.wikia.com/wiki/Relentless_Conviction work, specifically the "Increase base trigger chance of spells and items by 6%". Is this an additive bonus so for example Synergism 33%(base) + 6% rate would become 39%? Or multiplicitive so it would be 33% + 1.98%(33 x .06) = 34.98%? Assuming the second but wanted to double check.
It is the second, multiplicative, along with similar effects like "Luck of the Dirge" and "Asphyxiating Sorcery". I am not aware of any additive effects that increase proc chances, except just equipping a second item with the same proc (which will NOT work with many of the newer procs, that are designed to overwrite instead of stack).