7. Keywords and effects
Stun
Stopping a unit from dealing combat damage

says "Stun a unit." A unit that's been stunned deals no damage in combat. It's still there, and it still counts as being in the fight, but its Might adds nothing to its side's damage. To a unit is to put it in that state.
A stunned unit is still as tough as ever. It needs damage equal to its full Might to die, the same as before.
How long it lasts
Until the end of the turn. A unit stays stunned through every combat that turn, then it's back to normal.
A unit is either stunned or it isn't. Stunning a unit that's already stunned does nothing more.
An example
Your opponent attacks your (3 ) with a (4 ). In the showdown, you play Rune Prison on the Sergeant. Then the damage:
- Theirs is 0. The Sergeant is stunned, so it deals nothing.
- Yours is 3. The Sergeant needs 4 to die, so it lives too.
Both sides have units left, so the attacker goes back to base, and you keep the battlefield.
Try it
Stun an attacker in the showdown, and see the combat that follows.