What happens if two units are attacking, both with 4 might, to a unit with 6 might, but one of the 4-might units gets killed by an effect? Do they lose the combat?

In this scenario, you do not necessarily lose the combat, but the outcome depends on the total Might remaining on your side versus the defender's side at the moment combat damage is resolved.

The Ruling

Combat damage is calculated by summing the current Might of all attacking units and all defending units at the battlefield. If one of your attacking units is killed by an effect before the Combat Damage Step, its Might is no longer included in your total.

• Initial State: You have two 4-Might units (Total: 8 Might). The defender has one 6-Might unit (Total: 6 Might).
• After Effect: One of your 4-Might units is killed. You now have one 4-Might unit (Total: 4 Might). The defender still has their 6-Might unit (Total: 6 Might).

Combat Outcome

According to Rule 443.1, combat damage is resolved using the current Might of the units present at the battlefield.

1. Summing Might: Your total attacking Might is now 4. The defender's total Might is 6.
2. Assigning Damage: Starting with the attacker, players assign damage equal to their total Might. You assign 4 damage to the defender. The defender assigns 6 damage to your remaining unit.
3. Lethal Damage:
   • Your unit (4 Might) receives 6 damage. Since 6 is greater than or equal to its Might, your unit is killed.
   • The defender's unit (6 Might) receives 4 damage. Since 4 is less than its Might, the defender's unit survives.

Result: Because your total Might (4) was insufficient to deal lethal damage to the defender's unit (6 Might), and the defender's total Might (6) was sufficient to deal lethal damage to your remaining unit (4 Might), your unit is killed and the defender's unit remains on the battlefield.