At the start of the campaign, each player chooses a hero deck—Jungle Troll, Hill Halfling, Copper Dwarf or Wood Elf—and combines it with one of the four available classes: Warrior, Mage, Rogue or Druid. Every boss has its own unique tactics and abilities, strengths and weaknesses, which the group of heroes must first deduce and understand before they can effectively fight it. Upon successfully defeating a boss, players gain loot cards hidden in three secret loot boxes, which they can use to improve their decks and unlock new, powerful abilities. Each boss battle can be attempted at one of four levels of difficulty.