Through a lot of testing I have found that crit ting with your weapon or skills is at 125-130% damage increase, no matter if the spell says "increased damage on critical hits". This makes me think that Crit damage in general is broken for a lot of skills. Because they don't do anymore than a weapon Crit or skill without the "increased damage" tag. Because of this Crit builds are basically useless because of the low damage boost.