master the use of their core to summon spirits from different lands: Ruby Red from the Land of War ruled by dragons; Amethyst Purple from the Land of Undead ruled by Zombies and Evil Snakes; Emerald Green from the Land of Trees inhabited by seekers of the World Tree; and White Diamond from the Land of Ice ruled by Masters of Machines. Each booster pack includes: 8 Randomly selected cards (up to 6 Commons, up to 2 Uncommon, & 1 of 3 Rare card types) Rare Card - 3:4 packs Master Rare Card - 1:5 packs X-Rare Card - 1:23 packs  (less)