Pre-built decks are provided by the game. Decks may also be constructed by a player. Player-built decks are typically far more powerful than pre-built decks.
Decks may be saved in deck slots, to allow player-built decks to be easily reused in later games. Deck slots are limited, and additional deck slots for a Planeswalker may be purchased by spending in-game Resources.
Decks may only contain cards meeting Color requirements and card type requirements. These requirements depend on the Planeswalker for which the deck is being built. Some events further restrict decks based on card set.
- The color requirements of a deck are determined by the color affinity of the Planeswalker.
- For example, the deck of a Planeswalker with affinity for blue and green may only contain cards which are blue, green, or colorless.
- The deck limits of the Planeswalker set the maximum number of cards of each type (Creature, Spell, or Support) which may be included in a deck. Deck limits increase at higher Planeswalker levels.
- The card sets which a deck may contain cards from are determined by the event format.
During the game
The 10 cards in the chosen deck are the basis of the player's library. During a game, cards are drawn from the top of a player's library.
The library is initially formed by shuffling together 4 copies of each card in the deck. Whenever more cards are needed in the library, a further 4 copies of each card in the deck are shuffled together and added to the bottom of the library.