The Undermountain expansion gives players the chance to explore Undermountain, a vast and multileveled dungeon beneath Mount Waterdeep that once served the crazed wizard Halaster as a site for magical experiments. In this labyrinthine with few refuges for weary adventurers, players can enter new quests to discover rumored wealth but must brave the mysteries and monsters beneath the City of Splendors.

With three new Lord cards including the Wizard Halaster Black Cloak, clever dandy Danilo Thann, and Halaster’s apprentice Trobirand, players can test their skills on four new quests and new intrigue cards. An expanded gameboard with three new buildings and an extra agent, as well as a handful of new buildings for purchase, keep the gameplay challenging.