How do the Legend's domains limit a deck?

In Riftbound: the League of Legends trading card game, the Legend is the first card you choose for a deck, and its domains decide which other cards may join it. In the default card frame, a Legend shows its domains as symbols in its upper left corner. The Core Rules call these domains the Domain Identity of the deck, and rule 103.2.b says that every card in the deck has to abide by it.

The rule reaches every other part of the deck: the Main Deck with its chosen champion, the 12 runes of the Rune Deck and the battlefields. Every Legend printed so far has two of the six domains, so in practice a deck plays two domains and the cards that have no domain at all.

Which cards fit a Legend's domains?

A card fits when each of its domains is one of the Legend's domains. Rules 103.2.b.3 to 103.2.b.5 of the Core Rules spell out the three cases.

• One domain. A card with one domain fits when the Legend has that domain. Most cards in the game have one domain.
• Two domains. A card with two domains fits only when the Legend has both of them. Sharing one of the two is not enough.
• No domain. A card with no domain fits every deck. Every battlefield printed so far is such a card, and so is Neeko, Blending In, a unit from Radiance, the fifth set, with its release on 23 October 2026.

Heart of the Tempest, the Legend of Kennen from Vendetta, is Chaos and Order. A Kennen deck can play both of Kennen's champion units, Kennen, Storm of Shuriken in Chaos and Kennen, Keeper of Balance in Order, and Lightning Rush, his signature spell, which is Chaos and Order itself. Champion units of other champions fit too when their domain does. Twisted Fate, Gambler is a Chaos unit, so a Kennen deck may play him as an ordinary unit. Only the chosen champion has to carry Kennen's name.

A Kennen deck cannot play Jinx, Demolitionist, because that unit is Fury and Kennen has no Fury.

Which cards have two domains?

So far only Legends and signature cards have two domains. Every signature card carries the same two domains as the Legend of its champion: Super Mega Death Rocket! is Fury and Chaos, just like Jinx's Legend Loose Cannon.

In Constructed, a deck may only play the signature cards of its own Legend's champion, up to three in all. That rule already keeps every other champion's signature cards out, so the rule for cards with two domains changes nothing there yet. It does real work in Sealed and Draft, where signature spells are open to more decks, as the part on those formats below shows.

Do the runes and battlefields have to match the domains?

The runes do. All 12 runes of the Rune Deck must belong to the Legend's domains (rule 103.4.a.1), in any mix of the two, so a Kennen deck brings only Chaos Runes and Order Runes. A rune adds one Power of its own domain when you recycle it, so the rule also keeps your Power in the two domains your cards ask for. Riot's deckbuilding primer suggests six runes of each domain as a start, or eight and four in favor of the domain whose cards ask for more Power, so how many runes of each domain to bring depends on the cards in the deck.

The Core Rules make battlefields subject to the Domain Identity where it applies (rule 103.5.b). So far that never matters, because every battlefield printed is colorless and fits any deck. Choosing your battlefields therefore comes down to your plan, not to your domains.

Are the domains different in Sealed and Draft?

Yes. In Sealed and Draft, where decks are built from the packs opened at the event, a deck has three domains instead of two: any three, or its Legend's two domains and one more (Tournament Rules 602.4.a.3 and 602.4.b.4). A deck may even go without a Legend.

The wider identity loosens two other rules. The chosen champion can be any champion unit within the deck's domains, whatever its name. A signature spell fits whenever all of its domains are among the deck's three, even when the deck does not have that champion. A Sealed deck of Fury, Body and Order may play Noxian Guillotine, the Fury and Order signature spell of Darius, but not Super Mega Death Rocket!, which is Fury and Chaos. The runes may come from any source, but each one must match one of the deck's domains.

What happens when a deck breaks the domain rule?

At a tournament that registers decklists, a list with a card outside the Legend's domains is a Decklist Error, and the Tournament Rules set the penalty at a Game Loss (rule 703.3). The player then corrects the list with as little change as possible. In Constructed the Legend and the runes cannot change after registration (rule 403.4.b), and sideboard cards are swapped one for one into the Main Deck, so a sideboard has to stay within the same two domains as well.

The deck builder catches the mistake long before that. It names every card in the Main Deck or the Rune Deck whose domain the Legend does not have.

How should the domain rule guide your choice of Legend?

Choosing a Legend means choosing two domains, so look at the cards of both domains as well as at the champion. Six domains make fifteen possible pairs, and since Vendetta every pair has at least one Legend, so any card can be matched to a Legend whose domains include its own. Some pairs offer a wide choice: Fury and Chaos has Legends of Jinx, Draven and Zed, among others. Chaos and Order has only Kennen so far, and Mind and Body has only Jayce.

The Legends page lists every Legend with a filter for each domain, and the card list shows what each domain has to offer. The domains are only one reason to choose a Legend, because its ability and its champion matter as much, so how to pick a Legend looks at all three.