Keen (Weapon Enhancement) [DMG]
This magical enhancement doubles the threat range of a weapon. There is no restriction on what type of damage the Keen weapon must deal (piercing, slashing, or bludgeoning). This benefit doesn’t stack with any other effect that expands the threat range of a weapon (such as the keen edge spell or the Improved Critical feat).
Moderate transmutation; CL 10th; Craft Magic Arms and Armor, keen edge; Price +1 bonus.
Vorpal (Weapon Enhancement) [DMG]
This potent and feared ability allows the weapon to sever the heads and power sources of those it strikes. Upon a roll of natural 20 (followed by a successful roll to confirm the critical hit), the weapon removes the opponent’s head (if it has one) from its body, killing the creature outright.
A creature with multiple heads does not die outright from this attack, but has any benefits based on it’s dual headed nature reduced by a relevant fraction equal to 1/X, where X is equal to the number of heads this creature had. This attack also deals HP damage equal to the creatures maximum hp multiplied by 1/X.
Creatures that would suffer no ill effects from having their head removed, or have no specific head to have removed suffer the damage of a critical hit with the weapon with a multiplier of 1 higher. This critical cannot be negated by immunities to critical hits given from any source.
There is no restriction on what type of damage the Vorpal weapon must deal (piercing, slashing, or bludgeoning).
If used as part of a Coup De Grace, the weapon’s multiplier is increased by 1 for the purposes of the Coup De Grace damage.
Strong necromancy and transmutation; CL 18th; Craft Magic Arms and Armor, circle of death, keen edge; Price +5 bonus