Vorpal

Vorpal is a very rare and potent weapon effect. Targets struck with a critical hit by a weapon with this effect must make a successful reflex save (DC 20) or be killed instantly, regardless of health, presumably by decapitation.

Immunity to critical hits, regardless of source, prevents this effect.

The following weapons are know to possess the Vorpal Quality: Opponents immune to critical hits may still be killed instantly by weapons with the "on hit: slay racial group" effect. Examples include:
 * Headsman - a Falchion sold by Fibba (1)
 * Balor Longsword
 * Balor Lord Longsword
 * Pharaoh's Mace - a Mace (Slay Undead - DC 22) sold by Haljal Throndor (1)
 * Water's Edge - a Halbard (Slay Elemental - DC14) sold by Fibba (1)
 * Gutspiller - a Kukri (Slay Human - DC 14) sold by Dayne Lynneth (2)
 * Club of Smiting - a Club (Slay Construct - DC 14)

(1) Buying these weapons (available only during ACT II of the original campaign) requires the player possess the Blessed of Waukeen feat.

(2) Buying this weapon (available only during ACT II of the original campaign) requires the play possess the Merchant's Friend feat