Strikes, spells, hazards, and all number of other dangers can deal damage, which can kill creatures and destroy objects.

Damage decreases a creature’s Hit Points (HP) on a 1-to-1 basis (so a creature that takes 6 damage loses 6 Hit Points). The full rules for losing HP can be found in the Hit Points, Healing, and Dying section.

Damage is sometimes given as a fixed amount, but more often than not you’ll make a damage roll to determine how much damage you deal. A damage roll typically uses a number and type of dice determined by the weapon or unarmed attack used or the spell cast, and it’s often enhanced by various modifiers, bonuses, and penalties. Like checks, a damage roll—especially a melee weapon damage roll—is often modified by a number of modifiers, penalties, and bonuses. When making a damage roll, you take the following steps, explained in detail below.

1. Roll damage dice indicated by the weapon, unarmed attack, or spell, and apply the modifiers, bonuses, and penalties that apply to the result of the roll.
2. Determine the damage type.
3. Apply immunities, weaknesses, and resistances the subject has to the damage.
4. If any damage remains, reduce Hit Points the target has by that amount.

Step 1: Roll Damage Dice

Your weapon, unarmed attack, spell, or even a magic item determines what size and number of dice you roll for damage. For instance, if you’re using a normal longsword, you’ll roll 1d8. If you’re casting a 3rd-rank fireball spell, you’ll roll 6d6. Sometimes, especially in the case of weapons, you’ll apply modifiers, bonuses, and penalties to the damage.

Damage rolls for melee weapons and unarmed attacks typically add your Strength attribute modifier.

Melee damage roll = damage die of weapon or unarmed attack + Strength modifier + bonuses + penalties

Damage rolls for ranged weapons typically don’t add an attribute modifier, though you add your Strength modifier to damage rolls for thrown weapons or half the modifier to damage rolls for ranged weapons with the propulsive trait.

Ranged damage roll = damage die of weapon (+ Strength modifier for a thrown weapon or half Strength modifier for a propulsive weapon) + bonuses + penalties

For damage rolls with spells, alchemical bombs, and similar items, you don’t add an attribute modifier unless otherwise noted.

Spell (or similar effect) damage roll = damage die of effect + bonuses + penalties

As with checks, you might add circumstance, status, or item bonuses to your damage rolls, but if you have multiple bonuses of the same type, you add only the highest bonus of that type. Again like checks, you may also apply circumstance, status, item, and untyped penalties to the damage roll, and again you apply only the greatest penalty of a specific type but apply all untyped penalties together.

If the combined penalties on an attack would reduce the damage to 0 or below, you still deal 1 damage. Sometimes there are other considerations, described below.

Adding Damage Dice

Each weapon lists the damage die used for its damage roll. A standard weapon deals one die of damage, but a magical striking rune can increase the number of dice rolled, as can some special actions and spells. These additional dice use the same die size as the weapon or unarmed attack’s normal damage die.

Counting Damage Dice

Effects based on a weapon’s number of damage dice include only the weapon’s damage die plus any extra dice from a striking rune. They don’t count extra dice from abilities, critical specialization effects, property runes, weapon traits, or the like.

Increasing Die Size

When an effect calls on you to increase the size of your weapon damage dice, instead of using its normal weapon damage dice, use the next larger die, as listed below (so if you were using a d4, you’d use a d6, and so on). If you are already using a d12, the size is already at its maximum. You can’t increase your weapon damage die size more than once.

1d4 » 1d6 » 1d8 » 1d10 » 1d12

Persistent Damage

Persistent damage is a condition that causes damage to recur beyond the original effect. Like normal damage, it can be doubled or halved based on the results of an attack roll or saving throw. Unlike with normal damage, when you are subject to persistent damage, you don’t take it right away. Instead, you take the specified damage at the end of your turns, after which you attempt a DC 15 flat check to see if you recover from the persistent damage. See the Conditions Appendix for the complete rules regarding the persistent damage condition.

Doubling and Halving Damage

Sometimes you’ll need to halve or double an amount of damage, such as when the outcome of your Strike is a critical hit or when you succeed at a basic Reflex save against a spell. When this happens, you roll the damage normally, adding all the normal modifiers, bonuses, and penalties. Then you double or halve the amount as appropriate. As normal, round down if you halve the damage (though 1 damage halved remains at a minimum of 1 damage).

When doubling, the GM might allow you to roll the dice twice and double the modifiers, bonuses, and penalties instead of doubling the entire result, but this usually works best for single-target attacks or spells at low levels when you have a small number of damage dice to roll. Benefits you gain specifically from a critical hit, like the extra damage die from the fatal weapon trait, aren’t doubled.

Step 2: Damage Type

Once you’ve calculated how much damage you deal, you’ll need to determine the damage type. The smack of a club deals bludgeoning damage. The shock of a lightning bolt spell deals electricity damage. Sometimes you might apply precision damage, dealing more damage for hitting a creature in a vulnerable spot or when the target is somehow vulnerable.

Step 3: Apply Immunities, Weaknesses, and Resistances

Defenses against certain types of damage or effects are called immunities or resistances, while vulnerabilities are called weaknesses. Apply immunities first, then weaknesses, and resistances third.

Step 4: Reduce Hit Points

Any remaining damage reduces the target’s Hit Points on a 1-to-1 basis. More information can be found in the Hit Points, Healing, and Dying section.

Nonlethal Attacks

You can make a nonlethal attack to knock someone out instead of killing them (see Knocked Out and Dying). Weapons with the nonlethal trait (including fists) do this automatically. You take a –2 circumstance penalty to the attack roll when you make a nonlethal attack using a weapon or unarmed attack that doesn’t have the nonlethal trait. You also take this penalty when making a lethal attack using a nonlethal weapon. Spells and other effects with the nonlethal trait that reduce a creature to 0 Hit Points knock the creature out instead of killing them.