Sideboard

• Each player may also have a sideboard, which is a group of additional cards the player may use to modify their deck between raids or during intermission points during a multi-part raid.
• A sideboard may contain no more than fifteen cards which are not restricted by the normal deckbuilding restrictions.
• Companions start the game in the sideboard and count toward the total number of cards in the sideboard.
• Cards in a sideboard must match, or be a subset of, the commander’s color identity.