The numerical part of a creature's
damage reduction is the amount of
hit points the creature ignores from normal attacks. Usually, a certain type of weapon can overcome this reduction. This information is separated from the
damage reduction number by a slash.
Damage reduction may be overcome by special materials, by magic weapons (any weapon with a +1 or higher enhancement bonus, not counting the enhancement from masterwork quality), certain types of weapons (such as slashing or bludgeoning), and weapons imbued with an
alignment. If a dash follows the slash then the
damage reduction is effective against any attack that does not ignore
damage reduction.
Ammunition fired from a projectile weapon with an enhancement bonus of +1 or higher is treated as a magic weapon for the purpose of overcoming
damage reduction. Similarly, ammunition fired from a projectile weapon with an
alignment gains the
alignment of that projectile weapon (in addition to any
alignment it may already have).
Whenever
damage reduction completely negates the
damage from an attack, it also negates most special effects that accompany the attack, such as injury type
poison, a
monk's stunning, and injury type
disease.
Damage reduction does not negate touch attacks, energy
damage dealt along with an attack, or energy drains. Nor does it affect poisons or diseases delivered by inhalation, ingestion, or contact.
Sometimes
damage reduction is instant
healing. Sometimes
damage reduction represents the creature's tough
hide or body,. In either case, characters can see that conventional attacks don't work.
If a creature has
damage reduction from more than one source, the two forms of
damage reduction do not stack. Instead, the creature gets the benefit of the best
damage reduction in a given situation.