Through out the game, players will be able to purchase or obtain new cards to add to their library. Any cards in a player's library are spells that player may cast. Players may use Knowledge Points, which are gained primarily by leveling up, to purchase new cards to add to their library. Any time a player obtains a new card, if that cards causes the player to exceed their Maximum Library Size, then they must sell cards from their library until their library size is equal to their Maximum Library Size. Land cards do not count towards this total, and do not cost any knowledge points.
The Dueling DeckEdit
Not all cards in a player's library are required to be put into the character's duel deck. A player builds his/her deck out of the cards that they own. This allows players to purchase cards that may not fit well with their deck for use in other areas, (such as for healing, or creature summoning for damage).
A player is given a deck of 36 cards at level 1. All player's maximum library size at level 1 is 36 cards (lands don't count towards your library), so a level one character's library will begin completely full.
A player's Dueling Deck is required to have a minimum of 60 cards in it at all times. If a player has less than 60 cards to put in their deck, they must fill their deck with land cards to meet the 60 card minimum.
There is no maximum deck size, but you cannot own more cards than your maximum library size at any given time.
The Side BoardEdit
Any card's that a player has can be removed from the player's dueling deck and placed in their side board. Cards in the side board cannot be used in a duel, but can be used outside of combat regularly. If the removal of cards from the deck to the side board causes a player's deck to fall below 60 cards, the player must replace the cards with other cards or add more lands to their deck to meet the 60 card minimum.