[Donjon] Overlapping Abilities

[Manxome]

Correct me if I'm wrong about any of the details of the rulebook, I'm working from memory...

I believe that the rules on Resolution (Chapter 4) state that no more than one ability can be used in any action.

However, one of the sample characters has a secondary ability "Deal Damage to Demons," and the explanation notes that this could be used to deal damage with weapons or spells or anything else at the character's disposal (in contrast to another sample secondary ability that dealt damage against anything but only using bare hands).

But offensive spells don't seem to have a separate to-hit and damage roll like weapon attacks, and instead the successes used in casting the spell get applied as damage directly?  And this roll already uses spellcasting ability as a bonus.

Should offensive casters first be making some sort of uncontested check to get the spell off and carry over successes into a damage roll?  Or is spell damage a special exception to the one-ability rule?  Would "Dealing Damage with Magic" (or maybe "Fire Magic") be an acceptable secondary ability?


One person I talked to was also suggesting using "Gather Magic Power" as a secondary ability to provide an additional bonus when charging up for a spell, but allowing that sort of double bonus sounds rather dangerous to me.