From DDO wiki
- +3 for falchion, great crossbow, kukri, rapier, and scimitar.
- +2 for bastard sword, dagger, greatsword, heavy crossbow, khopesh, light crossbow, long sword, repeating heavy crossbow, repeating light crossbow, short sword, and throwing dagger.
- +1 to all other weapons.
- Multiple versions of this feat exist, one for each weapon type (Bludgeoning, Piercing, Ranged, Slashing or Thrown). This feat can be taken multiple times, though each time must be for a different type.
- Shields do not benefit from Improved Critical.
- An Artificer may select this feat as one of his artificer bonus feats.
- A Fighter may select this feat as one of his fighter bonus feats.
For artificers taking it as a bonus feat, it is restricted to ranged and slashing, though.