Rules – Primordial Format

Deck-building

A Primordial deck must contain at least 40 cards, all cards must come from the same set (reprints are allowed) and:

Exactly 2 mythic rare / rare – not more than 1 of any individual mythic rare / rare
Exactly 6 uncommon – not more than 2 of any individual uncommon
∞ Common – not more than 4 of any individual common, except for basic lands
Up to 8 cards in the sideboard, if used

Additional rules

Archive Rule
- Strixhaven: School of Mages (STX) and Strixhaven Mystical Archive (STA) are treated as though they are one set for Primordial. Cards from STA may be included in a STX deck at their printed rarity in STA. This rule is also true for The Brother’s War (BRO) and The Brothers’ War Retro Artifacts (BRR). As of this message, the rule is only true of the previously mentioned sets. This rule is not true for sets such as Kaladesh Inventions (MPS) or Amonkhet Invocations (MP2).
Basic lands:
- The following basic lands can be played in any set : Plains, Island, Swamp, Mountain and Forest.
Cards rarity:
- The rarity of the cards depends on the set of your deck.
- The rarity of Timeshifted cards depends on their original set (Arena is considered as rare).
Cards saying, “a deck can have any number of cards named […]”:
- Well, as it is written above… a deck can have any number of these cards (no matter their rarity).
Cards that explicitly refer to another card from another set:
- These cards can be played together, as if they were from the same set (e.g.: Gate to the Afterlife explicitly refers to God-Pharaoh’s Gift).
Wishing, Learning, and Companion Rarity Rule
- No rare or mythic rare can be brought into a game from outside the game. This means that players cannot “Wish” or use the Learn ability to choose rare or mythic rare cards from their sideboard, and Companions cannot be brought in by paying for their ability. Players are still able to sideboard in rares or mythic rares in between games during a match, so long as their deck meets the rarity restrictions afterwards.
Sideboard:
- Your sideboard may only contain cards printed in the set of your deck, in any number of copies (e.g.: if you’re playing a Throne of Eldraine deck, it may contain 8 Oko, Thief of Crowns). However, your deck must still be compliant with the Primordial deck-building rules after swapping (2 mythic rare / rare, etc.). This is meant to be for wish players (e.g.: Fae of Wishes // Granted).

Multiplayer

Primordial is using the free-for-all Commander system for its multiplayer mode. In other words, your deck must still be compliant with the Primordial format deck-building rules (no commander, 1 set, 40 cards minimum, etc.) and your games should look like this:
- 2-6 players
- Free-for-all multiplayer format
- Start with 20 life
- Take turns in clockwise order
- Last player standing wins
Also, as it used to be stated in the Official Commander Rules: “House rules or ‘fair play’ exceptions are always encouraged if they result in more fun for the local community”.