Resistance and Vulnerability

Some creatures and objects are exceedingly difficult or unusually easy to hurt with certain types of damage.

The damage types are acidadamantcoldeldritchfirelightningmundanenecroticpoisonpsychicradiant, and thunder.

The most common damage type is mundane damage, which represents bludgeoning, piercing, and slashing forces. Some damage has no type.

Resistance: If a creature or an object has resistance to a damage type, damage of that type is halved against it (round down).

Vulnerability: If a creature or an object has vulnerability to a damage type, damage of that type is doubled against it.

Multiple instances of resistance or vulnerability that affect the same damage type count as only one instance. For example, if a creature has resistance to fire damage and resistance to all nonmagical damage, the damage of a nonmagical fire is reduced by half, not three-quarters.