Am I right in thinking that the chance to hit or graze is not improved by a higher crit chance? How can you calculate the odds of a graze? Is there a master chart anywhere spelling out the interactions between resistance, range and crits etc?
Now this is more complicated:
Graze is as Uto_piec said, "hit chance +25%".
Crit is a seperate roll, made before the hit roll. A critical means you always do full hits +50% damage this attack. I think those also guarantee Secondary effects to apply.
So if you got 25% Crit, 50% Hit the chances are:
First a roll on 25% is made if you crit. If you roll those 25%, Hit chance is ignored and you do full hits with the Crit Bonus. The same is true abotu fumble rolls. And it is possible to have both (high Morale + Roy-2 Distracting Pheromones).
If you fail the crit, a 50% Hit roll is made. If you hit, you do Full hits.
If the Hit roll fails but not by more then 25% (51-75%), you still do grazing hits at 50% damage (and no Secondary Effects)
That also means that starting with 75% or more, you are
guarnteed to do some damage. Even if you fail the hit roll, you will at least Graze.
It is worth nothing that with 1.006, effective Crit Chance is capped at Hit Chance. So if you got a listed 50% crit but only 25% hit on this attack, you only roll 25% crit. This pre-emtpively avoids Crit overstacking as a poissble source of abuse.