The library also consists of a hero and event cards, but they cannot be drawn. Instead, they are placed on the battlefield and cannot be removed.
Each library must have exactly 1 hero card and exactly 8 event cards and at least 50 cards of any other type. The type of card is restricted, depending on the hero's magic schools and factions, although cards of neutral type can be placed into any library. The hero can place up to four copies of the card in one library. The exception are unique cards, where only one copy can be placed in the library.
During the battle, the player draws one card from their library. They can also pay one resource to draw an additional card. If the player runs out of cards during the battle, they take one damage each turn.
At the start of the game, one of the starter decks can be chosen. There are six factions from which a library can be chosen. These are: