Countering Blade Wind - Early Era

[mivayan]

FAJ said:
Also, in the spell description, when the damage is a number: the HP lost, is that [damage - (armor +DRN)]? and if the damage is (damage+), the HP lost is [(damage+DRN) - (armor+DRN)]?

Both attacker and defender always gets a DRN. 10+ damage just means a bonus for having higher magic skill than needed.

So, hp loss is attacker roll - defender roll
attacker roll: DRN + spell damage + damage for extra skill, for some spells
defender roll: DRN + 0 (or +armor/2 or +armor, depending on if it's armor negating, armor piercing, or neither).