What is a card's Energy cost?

Every unit, spell and gear in Riftbound: the League of Legends trading card game has a number in its top left corner, and that number is the card's Energy cost. It says how much Energy you have to pay to play the card. Each rune on your board can make 1 Energy a turn, so the Energy cost is also the quickest way to see how big a card is and how early in a game it can come down.

Where is the Energy cost on a card?

The Energy cost is the large number in the top left corner of the card. The domain symbols stacked under that number, when a card has any, are a second part of the cost called the Power cost, and it is paid separately.

Eager Apprentice, a Mind unit from Origins, costs 3 Energy and no Power. Seal of Rage, a Fury gear, costs 0 Energy and one Fury Power. Elder Dragon, a Body unit from Unleashed, costs 12 Energy and four Body Power, which is the highest Energy cost printed so far.

How do you pay an Energy cost?

You pay an Energy cost with Energy, 1 Energy for each point of the cost. Every basic rune can be exhausted, turned sideways, to add 1 Energy. Energy has no domain, so a rune of any domain can pay the Energy of any card. To play Eager Apprentice, you exhaust three runes, whatever their domains are.

An exhausted rune stays on the board and readies again at the start of your next turn, so the runes you spend on Energy come back. The Power of a cost is paid by recycling a rune instead, which puts that rune on the bottom of your Rune Deck until you channel it again. A card with both costs is paid for by exhausting runes for the Energy and recycling a rune for each Power.

Which cards have an Energy cost?

Units, spells and gear have an Energy cost, and together they make up the main deck. Your chosen champion is no exception: you play it from the Champion zone and pay its Energy cost like any other unit.

Legends, runes and battlefields have no cost, because they are never played. The Legend and the battlefields start the game in play, and runes come onto the board when you channel them. Tokens have no printed cost either, since other cards create them during play. The Core Rules treat the cost of a token as 0 for every purpose, so a Recruit unit token counts as costing 0 whenever a card asks.

Card abilities can have an Energy cost too, written before the colon of the ability. Renekton, Brute, a Body champion unit from Vendetta, has an ability that costs 1 Energy and gives the unit +1 Might this turn.

How low and how high do Energy costs go?

Energy costs run from 0 to 12 among the cards printed so far, and most cards sit in the middle: about three in four units, spells and gear cost between 2 and 5 Energy. At the bottom are the six Seals of Origins, one gear for each domain, among them Seal of Rage and Seal of Unity, and Called Shot, a Chaos spell from Spiritforged. These seven cards cost 0 Energy, but each one still asks for one Power. At the top, Volibear, Imposing, Master Yi, Unstoppable and Elder Dragon each cost 12 Energy.

The Energy cost also tells you roughly when a card can come down. You channel 2 runes in each of your turns, so if you go first and recycle no rune, you have 2 runes on your first turn, 4 on your second and 6 on your third. A card that costs 6 Energy comes down on your third turn at the earliest, unless another card lowers its cost or adds Energy, and a card that costs 12 needs all 12 runes of your Rune Deck on the board. The player who goes second in a Duel channels one extra rune on their first turn and keeps that lead through the opening turns.

That is why some of the most expensive cards carry a discount of their own. Master Yi, Unstoppable costs 2 Energy and one Calm Power less at Level 3, and 6 Energy and three Calm Power less at Level 11, which leaves 6 Energy and no Power to pay. Rhasa the Sunderer costs 10 Energy, and 1 less for each card in your trash.

Can a card's Energy cost change during a game?

Yes. A card's Energy cost can go up or down while you play it, but the number printed on the card never changes. Before you pay, the game works out the total cost: it starts from the printed cost, adds any extra costs and cost increases, and then takes off any discounts.

• Discounts. Noxus Hopeful has Legion and costs 2 less when you have already played another card this turn. Sky Splitter, a Fury spell, has its Energy cost of 8 reduced by the highest Might among your units. Herald of Scales makes your Dragons cost 2 Energy less, to a minimum of 1, so Elder Dragon costs 10 Energy while you control Herald of Scales.
• Increases. Helm of Suppression, a Calm gear from Vendetta, makes your opponents' spells cost 1 Energy more, and 1 Energy and one Power more once it is Empowered.
• Ignoring the cost. The Harrowing plays a unit from your trash ignoring its Energy cost. You still pay the Power cost of that unit.
• Extra costs. An extra cost you choose to pay is added to the total. Accelerate asks for 1 more Energy and one Power of the unit's domain, and in return the unit enters ready.

No discount can take an Energy cost below 0, and some discounts, like the one from Herald of Scales, stop at 1.

Which number counts when a card checks an Energy cost?

The printed Energy cost always counts. When a card asks what another card costs, the Core Rules use the cost printed on it, even if that card was played for more, for less or for nothing.

The Core Rules give Lux, Illuminated, a Mind champion unit from Proving Grounds, as their example. Its ability gives it +3 Might this turn when you play a spell that costs 5 or more, and Sky Splitter counts as a spell that costs 8 even when its discount let you play it for 0. Get Excited! works the same way. It makes you discard a card and deals that card's Energy cost as damage to a unit at a battlefield, so a discarded Sky Splitter deals 8.

Cards that check an Energy cost have been printed in every set since Origins. Defy counters a spell that costs no more than 4 Energy and no more than one Power. Noxian Demolitionist can kill a gear with an Energy cost no higher than its own Might when it conquers. Several cards of Radiance, the fifth set, with its release on 23 October 2026, reward cards that cost 7 Energy or more, and Sanctum Conservator readies whenever you play one.

Why does the Energy cost matter when you build a deck?

The Energy costs of your cards decide whether you can use all your runes on each turn. A deck needs cheap cards for its first turns and only a handful of expensive cards that are worth waiting for. The spread of costs across a deck is its Energy curve, and a good Energy curve lets you spend most of your runes on every turn.

The card list can be sorted and filtered by Energy, and the deck builder draws the Energy curve of your deck while you build it. Energy is only half of what many cards ask for, because they also have a Power cost that needs Power of a domain on top of the Energy.