Aimed spells in the Sagas A Family Affair or Stranggore do damage like weapons. The targeting roll is like an Attack roll, compared against the target's Defense Total. The Attack Advantage carries over to damage just as if the spell were a missile weapon with a Weapon Damage Bonus of +X (where X is given in the spell's description). This is in contrast to the official rules, where spells do a stress die + X damage.
The purpose of this is to slightly tone down the damage of aimed spells, especially when multi-cast.