The Roiling Incant (Bestiary 3, page 216) is Immune to Evocation (it doesn't specify spells... just says "Evocation"). Weapon Potency Runes have the Evocation trait. Therefore, Roiling Incants are immune to damage from basic magic weapons using Runes, but completely vulnerable to specific magic weapons (like a Retribution Axe) that are +1 magic weapons, but do not have the Evocation trait. That correct?
I swear sometimes these rules make my brain hurt. LOL
Wasn't there something about this in an errata... Removing the mechanics of applying the traits of a weapon to the damage that it does.
Maybe I'm not remembering it right.
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But anyway, it is completely too bad to be true that a runed weapon can't do damage so you have to use Improvised Pummel with a random thing, or be using Automatic Bonus Progression or High-Quality weapons that give the bonuses of runes without actually using magic.
Wasn't there something about this in an errata... Removing the mechanics of applying the traits of a weapon to the damage that it does.
Maybe I'm not remembering it right.
It's not in the errata, but earlier versions of the rules had a line about actions inheriting traits (such as Strikes with a flaming weapon having the fire trait) that was quietly removed later on.
I try to keep track of it here in my notes on the section on magic and immunity. It is properly linked
Consider the rules for subordinate actions The subordinate action doesn’t gain any of the traits of the larger action unless specified. Similarly note that Any ongoing effect that isn’t part of the spell’s duration entry isn’t considered magical. Basically what the rules say is that traits aren’t inherited.
A Strike with a magical weapon is not a magical ability, but the damage and the effect is still magical because of the spcific rule on fundamental runes on the weapon.
Finally in CRB page 451 this section was silently removed from the CRB 2nd printing without explanation or notice. Presumably because it was wrong. This rule does not exist anymore:
Damage types and Traits
When an attack deals a type of damage, the attack action gains that trait. For example, the Strikes and attack actions you use wielding a sword when its flaming rune is
active gain the fire trait, since the rune gives the weapon the ability to deal fire damage.
Anyway in this case the Roiling Incant is Immune to Evocation, but there is no Evocation directly affecting it. The Evocation is the rune on the weapon. The Evocation trait doesn't carry through onto the Strike.
Ah, yes. That's what it was.
It is complex. But it is required otherwise creatures that are immune to magic would be immune to magical weapons. Which is a huge problem.