Format Rules

What is it?

A format that identifies thematic sub‑identities within each region that control which cards can be played together in PvP.

Why?

To keep all cards playable, introduce creative deck-building constraints, and prevent unhealthy combos without bans or rotations.

Design Goals

1. Keep every card viable (no global bans/rotations).
2. Add meaningful constraints that shape deck identities.
3. Avoid degenerate cross‑region synergies.
4. Maintain a clear competitive format distinct from casual modes.

Source: original physical page 3 (public-edition page 2)

Benefits & Outcomes

Adds depth to deck-building without outright bans or rotations and encourages diverse strategies and exploration of underplayed archetypes.

• Competitive Integrity

  Prevents unhealthy combos that dominate metas. Establishes Ranked as reflection of competitive play (like LoL and TFT), but keeps casual modes unaffected.

• Retention & Return

  Players who loved specific champions/cards can still play them. No “feels bad” rotations → all cards remain viable.

• Design Freedom

  Developers can safely design new champions/cards without risk of cloning or power creep. Clear archetype identities evolve with lore.

Source: original physical page 10 (public-edition page 9). These outcomes are from the Plot Armor Strategies source document and are not an official Riot Games rules publication.

Format rules from the source document

• How It Works

  Some cards are tagged with a Region Expression. Each region has multiple possible “expressions” (sub-identities).

  Source: original physical page 4 (public-edition page 3)

• One Expression Per Region

  When deck-building, if you include a card with a Region Expression tag, you may not include cards from a different expression in that same region. Most cards will NOT have a Region Expression Tag. It is possible for a region to NOT have Region Expression Tag Cards. Cards without Region Expression tags can be freely included in deck-building.

  Source: original physical page 5 (public-edition page 4)

• Cross-Region Restrictions

  Certain powerful cross-region combos may also be restricted. This maintains fun expression identities while removing unhealthy combos. Example: Heisho, Shell of the World (Ionia: Mana Manipulation) + Spectral Matron (Shadow Isles: Revive/Ephemeral) = Banned Region Expression Synergy.

  Source: original physical page 6 (public-edition page 5)

• Champions & Dual-Region Cards

  Champions may carry expression tags. If a dual-region card has an expression tag for one of its regions, the restriction applies only if you select that region for deck construction. Example: An Ionia/Noxus dual card tagged with an Ionia expression only restricts you if Ionia is one of your regions. If you build as Noxus + another region, the Ionian tag is irrelevant.

  Source: original physical page 7 (public-edition page 6)

• Multi-Expression Cards

  Some cards may carry multiple expression tags if they’re particularly strong or overlap design space. Example: Aloof Travelers, tagged as Scavenge (Bandle City) and Scrap (Piltover & Zaun). Its dual tag limits cross-region pairing of discard and hand-control effects, keeping Aloof strong but stopping double-dip disruption between both regions.

  Source: original physical page 8 (public-edition page 7)

• Generated Cards

  Specific generation (Ex: “Create a copy of X”) overrides expression restrictions so the generated card functions as printed. However, random generation respects expression restrictions (it won’t randomly generate a card that would create an illegal expression pairing). Note: This only applies if this format is successful and changes are made in-client.

  Source: original physical page 9 (public-edition page 8)

• One Expression per Region

  Within a region, tagged cards must share a single Region Expression once a choice is forced.

• Cross-region restrictions

  Some Expression pairs from different regions cannot be combined in the same deck.

• Untagged cards

  Cards without Region Expression tags are generally unaffected by Expression rules.

Tournament policy

These event procedures are retained for Region Expressions tournaments. They are not defined in the 41-page Region Expressions explanation PDF.

• Best of 3

  Matches are Best of 3. Bring a prepared three-deck lineup.

• Pick & Ban

  Players pick and ban decks from the lineup before games begin.

• Three-deck lineup

  Each player submits exactly three decks for the event.

• Card-Locked

  A card may appear in only one of your three decks.

Format at a Glance:

The live Expressions-per-region chart uses the published format. Open any name for the full explanation.