Crazy Jerome
First Post
To boil this down to the simplest possible version: Any natural 20 is a crit, and the meaning of "crit" is "bonus damage equal to your attack bonus." So if you've got +7 to hit, then you get +7 damage any time you roll a 20 on the attack roll.
One of the nice minor side effects of that option is that a 10th level fighter forced to use a mundane dagger during an escape still crits pretty darn hard compared to 1st level guy with a battle axe. That is, "improved critical damage" is a function of getting better with an attack--which is the way things would really be in any kind of world with even a nod to realism. As opposed to "only people who train with specific weapons, have magic, or take special feats" hit harder on criticals.
There is a sense in which criticals are out of place in a system as abstract as D&D, with attack rolls and then a range of damages. They aren't as bad as "called shots to the head" in that respect, but still a bit off. This kind of critical mechanic fits the abstraction that "skilled guy hits harder".