A truncheon is essentially a heavier version of the sap - a one-handed martial weapon that deals nonlethal damage. As with a sap, a rogue wielding a truncheon can deal extra nonlethal damage with a sneak attack, but only if she proficient in its use.
|Martial Weapon - Melee|
Book of Exalted Deeds
|The weapon deals subdual damage rather than normal damage.|
Preferred weapon of: No known deity.