Dungeons. The new DLC, simply titled 'Dungeons', will include 50 new maps, and a "Conquest" mode.
According to the press release: "With these 50 new maps, players will be introduced to new challenges in their role as an insidious Dungeon Lord, bent on capturing foolish heroes and sucking their soul energy out of them. The Conquest mode allows players to duke it out with pesky little upstart Dungeon Lords, taking the battle to them and attempting to smash their Dungeon Hearts. The Dungeons DLC map pack is available now and requires the original Dungeons to run."
The DLC is available on Steam and on other digital distribution sites.