What damage does a good Champion's Reaction actually reduce?

Question

All 3 of the reactions of a good champion include the wording "resistance against the triggering damage", written in different ways. So a player of mine and I were debating about what is the "triggering damage" and what damage is actually reduced. Let's say that an enemy strikes a PC with a flaming sword for 9 physical slashing damage and 6 fire damage. The champion is level 4 and his reaction would give resistance 6. So a reasoning that could be made is that the triggering damage is actually the physical one since it is written first and could be considered the "carrier" for the fire damage. Or the triggering damage is all the incoming damage (making the reaction a lot stronger IMO). So, does this resistance only apply to the physical damage, making the PC take 9 damage total, or would the resistance apply to both types of damage reducing the total to 3?

Answer 1

The full text from all three reactions is:

The ally gains resistance to all damage against the triggering damage equal to 2 + your level

(emphasis mine)

"Damage" in PF2e means all damage generated by a single attack or spell, as a collective unit. The Damage Rules say:

1. Roll the 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 the target’s immunities, weaknesses, and resistances to the damage.

4. If any damage remains, reduce the target’s Hit Points by that amount.

So, the "triggering damage" referred to in the Champion's reaction is the total of all dice rolls, modifiers, bonuses, and penalties. This means that the 9 physical and 6 fire damage are treated as a single damage unit for the purposes of the reaction, even though there are two different damage types.

The Resistance Rules cover what "resistance to all damage" means in detail, but in short:

When an effect deals damage of multiple types and you have resistance to all damage, apply the resistance to each type of damage separately.

To use your example, against the triggering damage only (i.e. the 9 physical and 6 fire, which are treated as a single "unit" of damage) the ally has resistance 6 all and only takes 3 damage. Or to invert your example, if an attack does 1d10 physical + 1d6 additional physical damage, the resistance would only apply once, because the 1d10 and 1d6 are a single "unit" of damage of the same damage type.

Note that this resistance only applies to the damage from a single attack or spell, so if the triggering enemy has a separate follow-up action which also does damage, or your ally has persistent damage of the same type as the triggering damage, the resistance would not apply to those damages.

Therefore, yes, the ally only takes damage after applying the Champion's resistance to all damage types in the attack.

Answer 2

Total Damage 3

The (good-aligned) Champion reactions grant resistance to "all damage".

The resistance rules cover how resistance to all damage applies to something that does multiple types of damage:

It’s possible to have resistance to all damage. When an effect deals damage of multiple types and you have resistance to all damage, apply the resistance to each type of damage separately. If an attack would deal 7 slashing damage and 4 fire damage, resistance 5 to all damage would reduce the slashing damage to 2 and negate the fire damage entirely.

So in your example, the target would take 3 slashing damage. This is quite powerful, especially at higher levels when attacks are more likely to have mixed damage types.