What are buffs, and when is a unit Mighty?

Many cards in Riftbound: the League of Legends trading card game talk about buffs and about Mighty units. A buff is a counter that makes one unit stronger for as long as it stays on that unit, and Mighty is the word the cards use for a unit with 5 Might or more. Neither word is a keyword. Buff is an action that a card tells you to take, and Mighty describes a unit that other cards look for.

What is a buff?

A buff is a counter on a unit that gives it +1 Might. When a card says "buff a unit", you place a buff on that unit, and the unit keeps the extra Might for as long as the buff stays on it. You can only buff a unit when a card tells you to.

Cards of every kind hand out buffs. Pit Rookie buffs another friendly unit when you play it. The battlefield Navori Fighting Pit buffs a unit there when you hold it. Blind Monk, the Legend of Lee Sin, buffs a friendly unit each time you pay 1 Energy and exhaust it. To keep track, the Core Rules suggest the buff reminder card from a booster pack, such as the Buff card below, or any spare object, such as a coin. At a tournament, the object has to show clearly that it stands for a buff.

How many buffs can a unit have?

A unit can have one buff at a time, as the Buff card itself reminds you, so buffing a unit that already has one does nothing.

You may still choose an already buffed unit when a card tells you to buff one, but no buff is placed, so anything that depends on the new buff fails. Simian Ancestor readies itself when you buff it, and the Core Rules make clear that this does not happen when it was already buffed.

A few cards work around the limit. Iridescent Avian from Radiance, the fifth set, with its release on 23 October 2026, buffs a unit and gives it +2 Might this turn instead if the unit already has a buff. Lee Sin, Ascetic can have any number of buffs, and he can exhaust to buff himself.

How long does a buff last?

A buff lasts until it is spent or until the unit leaves the board. Unlike a bonus that lasts for the turn, it does not wear off when the turn ends. A unit keeps its buff when it moves between your base and the battlefields. When it goes to a hand, a deck, the trash or banishment, its buff is removed, and if the unit comes back, it comes back without one.

What does it mean to spend a buff?

Spending a buff means taking it off one of your units, usually to pay for something, and the unit loses the +1 Might that came with it. You can only spend buffs from units you control, and once the buff is spent, the unit can be buffed again.

Sett, Brawler buffs himself when he is played and when he conquers, and spending that buff gives him +4 Might for the turn. Wallop and Call to Glory can be played without paying their cost if you spend a buff as you play them. When Riven, Broken Blade from Radiance becomes exhausted, she can spend her buff to stun an enemy unit or to ready herself.

Keep damage in mind when you spend a buff. A unit printed with 3 Might that has a buff and 3 damage on it dies once you spend the buff, because it is left with 3 Might and 3 damage.

When is a unit Mighty?

A unit is Mighty while its Might is 5 or more. On the board, the game counts its Might as it is right now, with every bonus: a buff, a bonus for the turn, and Assault or Shield during a combat. A 3 Might unit that gets +3 Might this turn is Mighty until the bonus ends at the end of the turn.

In the hand, the deck and the trash, only the printed Might counts. Raving Witness from Radiance reveals the top card of your Main Deck when it moves and draws that card if it is Mighty, which means a unit card printed with 5 Might or more. Spells and gear have no Might, so they are never Mighty.

The Core Rules use Fiora, Victorious as their example of a Mighty card. She has 4 Might, and while she is Mighty she has Deflect, Ganking and Shield, so a single buff switches on all three keywords and losing it switches them off. Invigorating Bloom from Radiance gives a friendly unit +3 Might for the turn and draws a card when you exhaust it together with a friendly Mighty unit.

What is the difference between being Mighty and becoming Mighty?

A card that asks whether a unit is Mighty looks at it at that moment. Show of Strength draws a card for each of your Mighty units, and Jaull-Fish costs 2 Energy less for each of them.

A card that triggers when a unit becomes Mighty waits for the moment its Might goes from below 5 to 5 or more. A 4 Might unit that gets a buff becomes Mighty, while a 5 Might unit that gets one does not, because it was Mighty already. Grand Duelist, the Legend of Fiora, can be exhausted to channel a rune exhausted when one of your units becomes Mighty, and Fiora, Worthy lets you pay one Order Power to ready that unit.

A bonus for the turn can make the same unit become Mighty again on a later turn, while a buff that takes a unit to 5 Might keeps it Mighty from turn to turn.

Which decks use buffs and Mighty units?

Most of the cards that buff are Body, Calm or Order cards, and most of the cards that look for Mighty units are Body or Order cards. Several Legends are built around them. Blind Monk can buff a unit every turn, and The Boss, the Legend of Sett, can spend a unit's buff to save it from dying. Relentless Storm, the Legend of Volibear, lets you channel a rune exhausted when you play a Mighty unit.

Some cards make a buff worth more than +1 Might. Wizened Elder has another +1 Might while it is buffed, and Lee Sin, Centered gives your other buffed units at his battlefield +2 Might. Buffs are an easy first mechanic for a new player: a buff is +1 Might that stays, one per unit.

Every unit with its Might is on the units page, and every Legend is on the Legends page. A buff matters most in combat, where Might is both the damage a unit deals and the damage it takes to kill it, so one buff makes a unit hit harder and last longer at once. The full rules for buffs and Mighty units are rules 427 and 701 to 711 of the Core Rules on Riot's Rules Hub.