Activated Abilities
Some cards have an ability you use whenever you choose. It's written as a cost, a colon, then what it does: [1], [Exhaust]: Buff a friendly unit. Pay the cost on the left, and you get the effect on the right.
[Exhaust] means exhaust this: turn the card sideways. A card that's already exhausted can't pay [Exhaust]. It readies again at the start of your turn.
That's the catch. An exhausted unit can't move. A unit that uses its [Exhaust] ability is a unit that doesn't attack this turn. Decide which job it does. Your Legend has one of these too, and it doesn't fight, so it's often the best one to pay with.
You use these on your own turn, when nothing else is happening: not in the middle of a Showdown or a fight. So do it before you move. In the examples, [1] means 1 Energy, and a buff is a +1 Might bonus a unit keeps.
- Blind Monk (Legend): pay [1] and exhaust it to buff a friendly unit.
- Lee Sin, Ascetic: "[Exhaust]: Buff me." Then he's exhausted and stays home.
Lee Sin is ready at a battlefield. You use his "[Exhaust]: Buff me". Can he still attack this turn?
Your Legend's ability costs "[1], [Exhaust]". You have the Energy, but your Legend is already exhausted. Can you use it?
Peak Guardian (5) holds A. Lee Sin (5) is ready at your base, and your Legend can buff a unit for [1]. Who should pay [Exhaust]?
Make your guess, then play the drill to find out.
Words from this lesson
- Activated ability
- An ability you choose to use by paying its cost, written "cost: effect".
- Exhaust cost
- A cost written [Exhaust]: turn this card sideways. An already-exhausted card can't pay it.
From the Core Rules (2026-10-09): Activated abilities — cost: effect · 139 — Ready and Exhausted