Does the 'attack triggers only once per combat' rule prevent triggers from activating when a unit is recalled and attacks again in a later combat, or only when it attacks multiple times in the same combat?

Ruling: Attack triggers activate once per unit per combat. If a unit attacks multiple times in the same combat (e.g., via multiple Ride the Wind effects in one showdown), the trigger only activates once. If a unit is recalled and attacks again in a different combat, the trigger will activate again.

Sequence:

• First attack in a combat triggers the attack ability
• Additional attacks in the same combat do not trigger the ability again
• If the unit attacks in a new/different combat, the trigger activates again

Nuances:

• The restriction is per combat, not per turn or per game
• Multiple instances of effects causing attacks in the same showdown count as the same combat