If I have 4 Might Unit and my opponent Void Seekers first and then I play Quickdraw Gear and a Hidden Gear to live and then my opponent moves their unit in afterwards to finish me off, does my health heal or do I have X health remaining? When does health heal?

To answer your question, we must look at how damage persists on units and when healing occurs in Riftbound.

Does your unit heal?

No, your unit does not heal immediately. Damage marked on a unit persists until a specific healing event occurs. Dealing damage with a spell (like Void Seeker) or playing gear does not trigger healing.

When do units heal?

According to Rule 142.3.b (referenced in FAQ #8529), units heal at only two specific times:

1. During a Combat Cleanup: This occurs after any combat showdown resolves. When a combat showdown ends, all units on the board (not just those involved in the combat) heal all damage.
2. At the end of each player's turn: This occurs during the End of Turn Cleanup step.

Your Scenario Breakdown

1. Void Seeker: Your opponent plays Void Seeker to deal 4 damage to your 4-Might unit. The damage is marked on your unit.
2. Playing Gear: You play a gear (using Quick-Draw or from Hidden). If this gear provides a Might buff, your unit's current Might increases. If the Might buff is sufficient to make your unit's Might greater than the 4 damage marked on it, your unit survives.
3. Opponent Moves In: When the opponent moves their unit into the battlefield, a new showdown begins. Because the previous spell-based damage was not healed (as no combat showdown or end-of-turn cleanup occurred), that 4 damage remains on your unit.
4. Combat: If the opponent's unit deals combat damage to yours, that new damage is added to the existing 4 damage.
5. Healing: Your unit will only heal all damage once the combat showdown ends (triggering Combat Cleanup) or at the end of the turn, whichever happens first.

Summary of Damage and Might

• Persistence: Damage does not heal until the end of a showdown or the end of the turn.
• Survival: A unit dies if the total damage marked on it is equal to or greater than its current Might (FAQ #3401). If you use gear to increase your unit's Might above the damage marked on it, your unit will survive the Void Seeker damage.
• Combat: Any damage taken during the subsequent combat will be added to the existing damage. If the total damage equals or exceeds your unit's Might at that time, it will be killed.

Note: This interpretation is based on the rules regarding damage persistence and healing windows (Rule 142.3.b and FAQ #8529).