Some classes (principally the Bard, Ranger, Prowler and Warlord) receive class abilities which apply bonus damage. In addition, some weapon properties add bonus dice to a weapon's attacks. Bonus damage has the following characteristics, except where the description of the item, feat or ability in question explicitly states otherwise:
- Different sources of Bonus damage stack. A Ranger using a Flaming Sword with a Bard in the party would have three sources of bonus damage, all of which would contribute to his damage.
- Bonus damage is never multiplied on a critical hit.
- Bonus damage is not base weapon damage, so it does not improve at levels 6, 11, 16, 21, 26, and 31.
- Bonus damage is not the same as precision damage, and therefore bypasses any resistance or immunity to precision damage.
- If no damage type is specified, bonus damage deals the same damage type as the weapon or effect to which it is applied. That is, if a club has some property granting it +1d6 bonus damage of an unspecified type, the bonus damage is considered bludgeoning. If the same property were applied to a longsword, it would be considered slashing damage instead. Untyped bonus damage is never "unresistable" by DR or ER, unless it is specifically described as Primal bonus damage (see Primal Damage).