Monsters serve as the universal enemies of all players in Thunderstone. Through defeating monsters, players gain Experience (XP) for use in levelling their heroes. Monsters also serve as the primary scoring mechanic, with most providing a certain number of Victory Points (VP) for use at the end of a game session.
Some monsters also provide bonuses when they are revealed from the player's hand, such as a gold value in the Village or an additional Attack or Magic Attack value when entering the dungeon.
Battle effects of monsters only apply when they are fought, not when they are revealed from a player's hand.
Monsters are seperated into various classes such as Abyssal, Humanoid, or Doomknight. Some of these involve a second "sub-class", such as with Undead•Doom and Undead•Spirit.
It is by these classes that the dungeon deck is built during setup, typically from a random selection of three.