Rule 714

If more than one instance of Bonus Damage is applied or granted to a Deal action, all instances are summed and applied once.

• 714.1 Bonus Damage can only be a positive value, and can only increase the amount of Damage being distributed.
• 714.2 If, for any reason, Bonus Damage would be a negative number, then no Bonus Damage is applied to the action.

Official Core Rules