Damage Vulnerability
Vulnerability increases the damage a creature takes from an attack. Like resistances, vulnerabilities correspond to specific types of damage and are represented as either a whole number (which is added directly to the damage) or a multiplier. When a creature has vulnerabilities, any damage that they take of the vulnerable type is increased.
Multiple vulnerabilities do not stack, and when a creature has multiple vulnerabilities to the same type of damage, the larger vulnerability is taken. Even if an opponent is vulnerable to only one type of damage dealt with an attack, the damage received is increased as normal. If an attack deals two or more types of damage, and the creature has multiple vulnerabilities, only the largest vulnerability applies.
Resistance, Reduction, and Vulnerability
If a creature has Damage Vulnerability and also Damage Reduction or Damage Resistance, always apply the vulnerability first.
- The Skeletal Soldier is vulnerable, Radiant(5), to radiant damage. A cleric hits the skeleton with Ray of Light dealing 6 radiant damage. Since the skeleton is vulnerable to radiant damage, it takes 11 points from the attack (6+5=11).
- The Flaming Skeleton is vulnerable to cold damage [Cold (5), Cold(2x)]. It is hit with an attack dealing 15 cold damage and takes 30 points after applying the vulnerability (15x2 > 15+5). When hit with a different attack that deals only 3 points of cold damage, the skeleton suffers 8 points (3+5 > 3x2).
- The Infernal Knight has Fire Reduction 10 and Fire Resistance. It is afflicted with a vulnerability to Fire(2x). A wizard’s fireball deals 50 fire damage. First the vulnerability doubles the damage to 100, then reduction subtracts 10 (100-10=90), and finally resistance halves it to 45. The Infernal Knight takes 45 fire damage.