I don't get it. So if a fighter has 20/x3 weapon, he becomes unable to crit? If he has 19/x3 weapon, he threats on 19 but not on 20? Seems rather wierd... Would rather just put "20 is not auto success" but keep everything else fine. The current way it is quite confusing and block crits from many builds.

Then again, without the crit thingy it would not be worth anything as in most cases 20+mods is high enough to succeed in stuff anyways. :/

EDIT: The rerolling 20s might actually be a good flaw.