Description from the publisher:

Explore the mega-dungeon of Undermountain in this adventure for the world’s greatest roleplaying game.

In the city of Waterdeep rests a tavern called the Yawning Portal, named after the gaping pit in its common room. At the bottom of this crumbling shaft is a labyrinthine dungeon shunned by all but the most daring adventurers. Known as Undermountain, this dungeon is the domain of the mad wizard Halaster Blackcloak. Long has the Mad Mage dwelt in these forlorn depths, seeding his lair with monsters, traps, and mysteries—to what end is a constant source of speculation and concern.

• The follow up to Waterdeep: Dragon Heist, Dungeon of the Mad Mage takes adventurers deep into one of D&D's biggest dungeons. Each of Undermountain's twenty-three levels is an adventure setting unto itself, and the book includes a map for each one.

• Waterdeep, known as the City of Splendors, is one of D&D’s most iconic locations. Also the setting for the board game Lords of Waterdeeep, it’s the jewel of the Sword Coast—a sprawling melting pot held together by firm laws and swift justice.

• Dungeon of the Mad Mage is the second of two Dungeons & Dragons books set in Waterdeep. It picks up where the first, Dragon Heist, leaves off, taking characters of 5th level or higher all the way to 20th level.

• In D&D, you and your friends coauthor you own legend. Guided by a Dungeon Master, you create characters and play their roles in a story, rolling dice and navigating maps as you unfold a tale as li...