Follow up to a previous question, do cards played from a sideboard need to match your commander's colors? : r mtg Transitioning from Bo1 to Bo3: Learn the Goals of Sideboarding and How to Sideboard MTG Arena Zone Zendikar Expeditions Trading Card Games for sale eBay Two of the most oppressive lock cards in Old School MTG make terrific sideboard cards and some decks can even swing them in the main. One of these two cards will hit Is the sideboard size on Arena 15 cards?