Like its predecessors, Journey into Nyx has an ancient Greek themed top-down design, making use of many mythological tropes. The set contains 165 cards (60 Common, 60 Uncommon, 35 Rare, 10 Mythic) and includes randomly inserted premium versions of all cards. Fitting in with the "enchantment matters" theme, 59 of the set's 165 cards carry the enchantment type. The set introduces the Lamia creature type.