Waves of supernatural darkness sweep over the subterranean city of Stoneholme, quenching lights and bringing with it foul creatures of shadow. After heroically defending a group of dwarven children being ravaged by a group of these shadow beings, the PCs are approached by Shtawn Deppenkhut -one of the king's own advisers- and are offered the task of finding the source of the darkness that threatens the city. The PCs investigation takes them through the Underworld to hidden caverns, where demon worshiping priests offer living sacrifices in an attempt to plunge Stoneholme into everlasting darkness, a first step in destroying the hated city once and for all, but as it turns out the priests aren't the only ones behind this unfolding plan to destroy Stoneholme. Dark Days in Stoneholme is ideally suited for a group of dwarven adventurers. It is recommended that you have access to the Stoneholme section of the Rise of the Drow revised & expanded edition (2014) but it is not necessary to run the adventure. Also available for Pathfinder. Published by AAW Games.

An escaped duergar slave stumbles into the village of Elventree. With her she brings a malady that grips the small settlement in a bout of madness that seems unshakable. Can you find the source of the madness and save yourself and the village’s inhabitants? A four-hour adventure for 5th-10th level characters.

A 20-page adventure for OSE Save the wizard! A sunken cathedral on a quiet mountain lake hides a long forgotten temple to Mathanoga, God of Knowledge and wizardry. Abandoned by Man for centuries , but protected by the legend of man-eating fishmen lurking in it. Or until a few weeks ago the young wizad Elric embarked on its expedition. With help from the accademy of Greykeep he found the temple and began to explore it, hoping to uncover its ancient magical secrets. Now the wizard is missing and the accademy has put a bounty on its head: its weight in silver to whoever will find him and bring him home alive and well. Find magical secrets! Deep inside the temple are stashed many magical items, all sacred to the fishmen dwelling there, all worth dying for. Save Elric and the treasures will be yours! The Sunken Temple is an expert level Old School Essentials adventure for a party of 1-4 players. Perfect for a one shot or a random encounter in an hex crawl.

Ruins of the Grendleroot is a book of ten easy-to-prep and easy-to-run adventures for the fifth edition of the world's most popular fantasy roleplaying game. Designed for characters of 1st to 5th level, these adventures take place in the caverns, chambers, tunnels, and ruins of Blackclaw Mountain, within which lurks a strange otherworldly sentience known as the Grendleroot. Ruins of the Grendleroot focuses on the sense of mystery and wonder that comes from exploring ancient ruins and lost chambers. The central hub of these adventures, Deepdelver's Enclave, is a frontier outpost overlooking the ruined city of Shadowreach, set deep within the mountain. In Deepdelver's Enclave, adventurers and explorers recount tales of their explorations, trade treasure and artifacts, and enjoy their shared love of uncovering the mysteries of the mountain.

"The module takes place in a large cavern that is part of an extensive underground cave network. It can be used as a side-trek encounter in the Undermountain or Night Below campaign." -- from the adventure. Includes a small keyed map of the cavern.

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.”

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.

Tales of Lady Sepha Lekore are known throughout the lands. Now she’s gone missing and her father Lord Lekore is offering a reward to anyone that can find her. With promises of a tidy sum, the adventuring party can investigate the last place she was seen to try and locate her. What they find will take them into the Underdark lair of a drow noblewoman with her eloped love, the young Lady Lekore.

The Ghost Tribe of Orcs were driven from their home under Wyvern Tor by some terrible evil. They marched to Phandalin and attacked only to be defeated. Then, the heroes journeyed to the orc’s former settlement beneath Wyvern Tor and found the source of the orc’s sardonyx and the umber hulk that drove the orcs out. Now, the party has to go deeper to deal with the terror from the Underdark that caused all of this excitement.

The Red Plumes have increased patrols in the region surrounding Hillsfar, and a string of disappearances has followed in their wake. Naturally, this has roused the suspicion of the factions. Join your factions and find out the truth behind the missing farmers. A four-hour adventure for 1st-4th level characters.

Undermountain: The Caverns of the Many-Legged is an adventure detailing a hidden mini-level for Dungeon of the Mad Mage for characters of levels 12-13. It uses some of the story and lore of that book, but it can be incorporated or dropped into any setting or homebrew campaign. In a hidden part of Undermountain, former slaves feed their fat, monstrous queen who is fixated on revenge. A broken drow house has finally found a place to call home – only to become abominations. And a massive beast slithers, hunting for anything to satiate its hunger and quell its madness. Welcome to the Caverns of the Many-Legged. Which side, if any, will adventurers choose as they explore this hidden mini-level for Dungeon of the Mad Mage? In this adventure, you will find: a mini-level that can be easily incorporated into Dungeon of the Mad Mage a vivid cast of unique monsters and NPCs, including chitine warriors, a choldrith queen, a spellcasting draegloth, a mad yuan-ti anathema, and others (stat blocks provided for all creatures not in the Monster Manual) locations that could be used or adapted elsewhere, such as a chitine colony and a drider-controlled drow fortress a combination of roleplay, exploration, and combat encounters

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+.

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 Baronies of Erlkazar, once a prosperous region of pastoral tranquility, is now a land of nightmares and dread. Bandit armies plague the region, terrorizing the populace and surrounding countries of Calimshan, Tethyr, Amn, and Turmish. Though these threats are terrifying enough, it is nothing compared to what awaits the people of Erlkazar at night. In caves, tombs, and subterranean communities beneath the seemingly pastoral villages of Erlkazar live the secretive Night Barony. Ruled by the vampire Saestra and her legions of darkness, these monstrous denizens of the Five Baronies are the real power in the region. The country’s only hope of liberation is you.

Sekarvu is a typical beholder. It spent much of its youth exploring underground realms and killing everything it found. One day, it came upon a large cavern filled with violet fungi. At the edge of the cavern, it found a small band of adventurers who had all but succumbed to the toxins of the fungi's tendrils. They offered little resistance to Sekarvu as it approached and began to feed on their still-writhing bodies. With its first bite, the beholder's life changed forever. Pgs. 52-55

a baron recruits the party to find a set of magical swords as well as explore a mine shaft that connects to the under dark

The final confrontation with the giant, King Snurre, and the entry of mighty adventurers into the caverns under his stronghold (DUNGEON MODULE G3, HALL OF THE FIRE GIANT KING) discovered the Dark Elves, the Drow, had instigated the giant alliance and its warfare upon mankind and its allied races. 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 cavern area, encounter and map matrix keys, and an additional section pertaining to a unique new creature 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 first part of a series of three modules (with SHRINE OF THE KUO-TOA, D2, and VAULT OF THE DROW, D3), or as the fourth part of a continuing series of modules which form a special progressive campaign scenario (DUNGEON MODULES G1, G2, G3, D1, D2, D3, and Q1, (QUEEN OF THE DEMONWEB PITS). TSR 9019

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 kuo-toa are a piscine race with a psychic affliction that makes them behave erratically and invent gods when feeling threatened. That same affliction gives them the power to bring those gods to life. Blibdoolpoolp is the most widely worshipped, and thus most powerful, of their gods. Blibdoolpoolp views the kuo-toa as her children despite having been born after them. Like all good mothers, she nurtures and protects. One of her chief concerns is understanding the kuo-toa’s psychic affliction, which causes them to undermine themselves whenever they strive for greatness. She discovers that a corrupted elder brain deep in the Underdark has a connection to the race; though the connection gives them psychic powers, it also turns them into powerless thralls, explaining their self destructive behaviors. Constrained by the same leash on her children, Blibdoolpoolp seeks adventurers to destroy the elder brain. Its death would free the kuo-toa, but potentially at great cost: if the kuo-toa lose their powers, will Blibdoolpoolp die?

When the PCs stumble into the Feywild, they find themselves in the middle of Mithrendain— a glorious eladrin city of grace and beauty. But as the heroes find themselves the target of mysterious attacks, they begin to discover that something rotten lurks in the city’s heart. Sunlight bathes the soaring towers of the eladrin city of Mithrendain. Gentle breezes swirl through wooded parks and along well-kept streets, and in the ancient settlement whos golden hues have seen it named the Autumn City, thousands live in peace and prosperity. For centuries, the fomorian chasms deep beneath the city have stood silent below the great magical seals that closed them in the wanting days of the eladrin empire. Over long years, the folk of Mithrendain have forgotten the dark threats of old, becoming complacent in their tranquility. And so none suspect that corruption lurks at the heart of the city, spreading out from the shadows to taint all it touches. Pgs. 104-128