Price +1 bonus; Aura moderate divination; CL 6th; Weight
This special ability allows a weapon to find chinks in a foe’s defenses using the wielder’s knowledge of the target.

Whenever the weapon’s attack is a critical threat, the wielder gains a +4 bonus on the confirmation roll if she has 5 or more ranks in a Knowledge skill that would be used to identify the target’s creature type (such as Knowledge [planes] for an outsider opponent), or a +6 bonus instead if she has 15 or more ranks.
Requirements Craft Magic Arms and Armor, true strike; Cost +1 bonus