My friends and I had so much fun with the Crit Charts in our games (even Chris, whose character took a horrid blow to the head from that 4 armed Bone Golem in the Tomb of Horrors) that Chris and I hashed out some ways to better incorporate them into the game by creating a few Feats and Flaws that interacted with them. Enjoy!
Prerequisites: Weapon Focus
Benefit: Make a normal attack roll after choosing a hit location and apply the modifier to the AC of the target. +4 if Torso or Abdomen, +8 if Arms, Legs or Head.
If the attack is successful, it acts as an automatic roll of 3 on the Critical Charts. If the attack results in an actual critical hit, add +2 to your Critical Chart severity roll.
A called shot does not count as a critical hit without actually rolling one for the purposes of damage rolled.
Prerequisites: Base Attack Bonus +4, Weapon Focus, Power Critical
Benefit: Add +2 to all severity rolls made using the Critical Hit Charts
Improved Exacting Attack
Prerequisites: Base Attack Bonus +8, Weapon Focus, Power Critical, Exacting Attack
Benefit: Add +4 to all severity rolls made using the Critical Hit Charts.
This bonus overlaps, does not stack with the bonus for Exacting Attack.
Curse of the Black Knight
Effect: All Critical Chart severity rolls against you are made at +2.