Recent earthquakes have unearthed a small section of a lost dwarven fortress. The dwarves are long gone, but rumors suggest they might have left treasure or weapons behind. After a journey into the Underdark, the characters find a barred iron door bearing the names of several ancient dwarven clans. Pgs. 90-95

After a drow girl goes missing, characters must delve into the depths of the Underdark to bring her back. As they journey through the dark, characters discover not all monsters are monstrous and webs are capable of restraining all manner of creatures; in fact, they can capture magic itself.

An unexpected envoy arrives in Sporedome and offers to give aid against the fire giants of Maerimydra, if you are willing to help his people with a small problem. A two-hour adventure for 5th through 10th level characters. Optimized for five 8th level characters.

Rumors of faceless demonic creatures have been steadily rising in the Hillsfar region, and it is said that far below the surface of Faerun, nestled in the bowels of the Underdark, ancient terrors are stirring. The imperiled drow of Szith Morcane have extended an intriguing offer, but can the drow be trusted, and for how long? An eight-hour adventure for 11th-16th level characters.

The Underdark is a subterranean wonderland, a vast and twisted labyrinth where fear reigns. It is the home of horrific monsters that have never seen the light of day. It is here that the dark elf Gromph Baenre, Archmage of Menzoberranzan, casts a foul spell meant to ignite a magical energy that suffuses the Underdark and tears open portals to the demonic Abyss. What steps through surprises even him, and from that moment on, the insanity that pervades the Underdark escalates and threatens to shake the Forgotten Realms to its foundations. Stop the madness before it consumes you! Note for DMs: This adventure is not for the faint of hearted, to run or to play. The module starts with 10 NPCs traveling with the party through the grueling Underdark. This number can grow. The encounters within the book are often incredibly deadly for the characters that would be going through it. This is because the module expects them to run or talk their way through the events, or, in some cases, the module expects them to lose. If your players aren't the kind of party to run, talk, or surrender, do not get this adventure. The module almost requires that you use milestone leveling because the experience provided does not commonly get players to the levels they should be once they get to certain milestones in the story (7th when they leave the underdark, 15th when they face the demon lords.) Good luck and happy questing.

The most deadly dungeon ever devised! High-level characters brave the unexplored corridors of Deepearth to confront perhaps the most feared adversary in the AD&D game. The second chapter of the Bloodstone Pass saga follows the conclusion of the desperate war against the bandit army. A cold and bitter winter drives the villagers to the edge of starvation, and numerous horrors strike the town of Bloodstone Pass. Join the adventure as the heroes explore the depths of the ancient bloostone mines, now inhabited by fearsome demons. There they hope to uncover the fantastic treasures rumored to exist in the unknown darkness. But deep within the mines, all is not what it seems.... This module uses the new rules from the Dungeoneer's Survival Guide and Wilderness Survival Guide. The adventure also includes optional BATTLESYSTEM scenarios fought entirely underground. These supplementary products are not required to play the adventure, however. TSR 9168

A powerful new narcotic is making its way through the Spine of the World. Behind it is a secret that could change everything! Explore a lost city and discover the secrets hidden by the gods themselves. (TW: some drug use and the possibility for players to use drugs)

Having put down a rising of giants, it was discovered that the motivating force behind their depredations was that of long-forgotten evil - the Dark Elves. Determined to seek out these creatures, a body of doughty adventurers mounted an expedition to learn the strength of the Drow and bring retribution to them (DUNGEON MODULE D1, DESCENT INTO THE DEPTHS OF THE EARTH). This module contains background information, a large-scale referee's map with a matching partial map for players, referee's notes, special exploration and encounter pieces, a large map detailing a temple complex area, encounter and map matrix keys, and an additional section pertaining to a pair of unique new creatures for use with this module and the game as a whole. A complete setting for play of ADVANCED DUNGEONS & DRAGONS is contained herein. This module can be played alone, as the second part of a series of three modules (with DESCENT INTO THE DEPTHS OF THE EARTH, D1, and VAULT OF THE DROW, D3), or as the fourth part of a continuing scenario (DUNGEON MODULES G1, G2, G3, D1, D2, D3, and Q1, QUEEN OF THE DEMONWEB PITS). TSR 9020, From 1978

Part megadungeon, part underground expedition, Operation Unfathomable serves as both a one-shot adventure and a campaign framework. PCs are (optionally) drafted at swordpoint to recover the Nul Rod, a priceless artifact that was recently lost in a local prince's foolhardy attempt to destroy the Chaos Gods of the Underworld. The PCs have been drafted as an expendable set of pawns to venture into the vast and bewildering Underworld and retrieve the Nul Rod. With the Underworld's innumerable beasties being on high alert after the prince's expedition, the PCs must sneak through the incredibly dangerous Underworld. Fighting is not as important as stealth, fast-talking, and running away rapidly. This is the expansion from Sholtis's original Operation Unfathomable, released in Knockspell #5 (2011).

The Underdark holds many secrets. A series of earthquakes and eruptions have rocked a normally placid land. Strange creatures sighted in the dark of night raise fears across the already disturbed countryside. As tales of a lost race that once warred with the drow begin to surface, only the boldest adventurers dare to descend into the shadowy darkness.

Expand your game with this collection of 56 NPCs of various Challenge Ratings, thirteen of which include maps and details of their lairs. Add these NPCs as a side-quest, a main villain, a one-shot, a bounty for easy money, or however else you wish. Written by some of the best-selling authors on the Dungeon Masters Guild and outstanding podcasters, each NPC includes an image, a backstory, motives, flaws, and a stat block. Some even include new magic items!

This adventure is written with the intent that it takes place in the subterranean world called the Underdark in the world of Forgotten Realms, although it may be placed in other settings. Within the Underdark, Cyrog's lair can be placed anywhere though it is stated to be thousands of miles east of Gravenhollow. If you are running Out of the Abyss, you may want to have your players see the vision Cyrog Lives! Hail Orcus! (OOTA, 158). Additionally, it is recommended that this adventure be used for a party of 4 to 6 players, level 9 to 12. While merely hinted at through visions in Out of the Abyss, Orcus is roaming the Underdark unchallenged with an army of mind flayers at his disposal. Cyrog, the elder brain of a mind flayer colony in the Underdark has died. The demon lord Orcus has reanimated and taken control of it. The hive of mind flayers is now bent to Orcus's will through Cyrog as he strives to make all life in the multiverse into a vast undead horde under his control. The adventurers are contacted by a patron who gives them a special item (such as brain worms) to suppress their brain waves and make it possible to infiltrate the Cyrog's Lair without immediate detection. The adventurers must defeat or otherwise subdue mind flayers and a few guards, override the elder brain's mechanical defense system, and slay Cyrog.

Detailed encounter, easily convertible into an adventure. Starts from investigating ambushes on the mountain pass and quickly escalated into a more twisted story about duergars, alhoons, and treasure vaults. Setting-agnostic (classic fantasy - best)

Side-Trek adventure When your PCs gain access to the teleport spell, their whole world changes. That simple spell opens up instantaneous, long-distance travel. No more long overland journeys or dangerous retreats through hostile territory. All it takes is clasped hands and a word from the wizard, and poof! The PCs are where they want to go. Except that it isn’t that simple, because teleport isn’t foolproof. The off-target teleports are a matter of scattering your PCs someplace else on the map and forcing them to get their bearings and make the long overland journey anyway. But this Side Trek focuses on the really intriguing column on the teleport chart: “similar area.”

This 4 hour adventure for 3rd level characters begins in a prison cell where the adventurers must figure out a way to escape, acquire weapons and armor to defend themselves more effectively, and most importantly, escape a repurposed dwarven forge that has been appropriated by a fire giant who uses slave labor and even a captured red dragon wyrmling to smelt ore and forge an arsenal under the volcano Mt. Hotenow.

If absolute power corrupts absolutely, Matron Maelora best beware; her plans for total domination of the Underworld are already close to satisfactory completion, while attacks on the Upperworld have become increasingly successful. The other power-hungry drow families of Holoth may despise her but they know a true leader when they see one, and House Gullion has been revealed as the family to lead them all on the path to glory. With the entire Underworld in chaos and the Spider Goddess regularly communing with her chosen Matron, far greater dreams than mere regional conquest are within the grasp of the drow, as Maelora prepares her grand dark elf army for victory! With other mystical allies standing firm with the Matron, other Underworld races beneath her heel or cowering behind fortified walls, and every drow ready to play their part when she gives the word, what could possibly stop her from achieving her final triumph and fulfilling her destiny? But even the greatest of plans has a flaw if you look hard enough, and a party of stout heart and strong resolve can make a difference. At first, such a party may well believe it is on a smaller adventure, perhaps to win a few baubles or some small acclaim by rescuing a few kidnapped villagers. Soon, however, those adventurers will realise that much more is at stake, and that they are the ones who will need to make moves against the evil Matron Maelora and her increasing dominance if both the entire Underworld and Upperworld are to be saved. But how will they go about it? Can they ensure their own success when an entire city is standing against them? Only they have the chance to halt the Rise of the Drow! Published by AAW Games.

The Zhentarim ask the party to investigate what happened in one their most important underdark outposts. If the party accepts, they'll have to deal with maddening darkness, grimlocks, an insane kenku assassin and unpredictable mixtures of potions. A short, fun dungeon romp that is easily adapted to other settings and other patrons. The combination of utter darkness and a villain based on sound makes for fun shenanigans on the side of the DM. Feasible as a one shot for an efficient party. Two tendays ago, Zhentarim agents were to transport a shipment of rare potions between their Underdark outpost and the surface world. The shipment has yet to arrive, and the outpost is not responding to any sending spells. Growing worried, the outpost’s overseer sends a group of hireswords to investigate and return it to Zhentarim hands. This particular adventure deals with the delusions of madness of Fraz Urb'luu. It also features Muurmic, the mad kenku first described in the December 2015 issue of Dragon+.

She ran. Where to or for how long, she really couldn't say. The little flame of her oil lamp sputtered and went out a few times. She'd snap her fingers and make the wick flare to life, but she may as well have ran blind. The hallways were pitch black with soot and choked with smoke, every turn was a guess and every corridor a gamble. Unnatural screams echoed from every direction. Left, right, left again, was this the south or north end of the labyrinth? She had no idea. The next turn brought her face to face with a doorway completely consumed in blue fire. The room beyond was so bright she had to look through her fingers at it. A shadow covered her, a shape in the doorway: a hulking creature with a wolf-shaped muzzle and enormous pincers for hands, wreathed in the same blue flames. The screams were getting closer behind her, too. They had her cornered, again. The demon slammed its shoulders through the narrow opening, splintering the wood and stone. She dropped the lantern and let the wand in her sleeve fall into her waiting hand. With a word of power and a gesture, she appeared in the familiar bedroom: stuffy and reeking of wood smoke. She'd have to try again tomorrow, if she could remember. During an exploration on the sixth level of Undermountain, a strange invisible creature leads to a series of collapsed chambers that hide a forgotten secret and one of the most devastating forces known to the multiverse. Marambra Nyghtsteel, the forgotten apprentice of Halaster Blackcloak, has been locked away for an age deep within Undermountain. What point and purpose her forced seclusion has, only Blackcloak may know. When a spell consuming blue fire, known as The Spellplague is trapped within the chambers, a series of events have left Marambra, lost in her madness, struggling to survive.

The mine has been known as Tessount’s Folly for years, due to it producing nothing of value. Now Valmour, the youngest son of the mine’s late owner, has inherited the mine...and found something he should have left buried. Pgs. 56-81

From the magazine: "The monster you're sent out after is so dangerous that even mind flayers fear it. And the illithids want your help!" Earthquakes hit the area around Needlespire mountain, affecting both dwarven and deep gnome villages, and the local mining industry. Deep gnome expeditions discover an illithid outpost! This adventure includes roleplaying encounters with both deep gnomes and illithid in their quest for the true cause of the earthquakes. The creature causing the earthquakes is a draknor which has sent its huge tentacles into the earth seeking magma to fuel its growth. Pgs. 38-60