In combat, must a player assign might/damage if they have units with might, or can they choose not to assign any damage?

Ruling: Players must assign damage in combat if they have any might available. You cannot choose to take damage without assigning damage back if you have at least one might.

Nuances:

• You must assign lethal damage to all units if possible
• Even if assigning damage would kill an opponent's unit (like Kogmaw with a death trigger), you cannot avoid assigning the damage