A new Dungeons & Dragons supplement has expanded the Undermountain megadungeon to make it even more insanely dangerous for players.

Last month, Dungeons & Dragons released Waterdeep: Dungeon of the Mad Mage, a new adventure that updated the famous Undermountain megadungeon for Fifth Edition play. The new adventure mapped out every floor of every dungeon, but left spaces for DMs to build their own challenges and encounters.

A collection of writers from the Dungeon Masters Guild, a Wizards of the Coast website that publishes both official and third-party adventures, has released Undermountain: The Lost Chambers that adds 11 new adventures to the Undermountain dungeon crawl. All of the adventures can be seamlessly added into Dungeon of the Mad Mage, or can be integrated into any other dungeon.

Undermountain is a massive dungeon, but its true appeal is the diversity of experiences found on its various floors. The Lost Chambers adds to that experience by offering up adventures with a variety of tones, ranging from straightforward hack and slash encounters to explorations of ancient ruins to encounters heavy on role play.

One of the more unique adventures include an exploration of Undermountain's water purfication and sanitation system. This encounter not only explains what happens to all of the waste accumulated by Undermountain's denizens and adventurers, it also brings in a collection of modrons, some of Dungeons & Dragons' goofiest monsters.

Other adventures include encounters with new monsters like the treasure golem, a construct made entirely of gold coins, or introduce new powers that vie for control of Undermountain's resources and treasures. Several adventures involve ancient and evil aboleths and can easily be combined into a single cohesive plotline.

Undermountain: The Lost Chambers offers something for every adventuring party. Whether you're looking for some additional encounters to fill out your party's trek through Undermountain or are seeking some inspiration for adventures that take place far from the Forgotten Realms.

Undermountain: The Lost Chambers can be purchased here for $9.99.