Mirrodin booster pack contains 15 cards per pack. Distribution is 1 rare, 3 uncommon, and 11 commons. Released in 2003, Mirrodin is the first set in the Mirrodin block. The set contains 306 black-bordered cards (88 rare, 88 uncommon, 110 common, and 20 lands). This set is considerably artifact heavy with 137 different artifacts.