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.

Chase a choldrith trying to incite a war! Detour through an abandoned dwarven mine when your path is blocked by a cave in! Fight through dangerous beasts to get back on the choldrith's tail. In this 6-8 hour adventure for 4-5 characters of 3rd level, explore an old dwarven mine and fight through a hive of dangerous beasts to get back on the trail of the choldrith your group has been pursing. Includes: A 6-8 hour adventure for 3rd level characters 2 DM maps Copies of the maps suitable for use in your favorite virtual tabletop Stat blocks for all monsters the players might encounter. 4 new undead versions of NPCs Be sure to check out the first two installments in this series: Into the Underdark - Part 1 A Family Affair Into the Underdark - Part 2 The Spider's Den

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

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.

Dark Water Trap is a mini-adventure that has a single encounter that involves Duergar using darkness and anti-darkvision to get the player to fall into a Pit trap full of water, so that the party will drown. The encounter either works as a standalone (Ie. the Duergar have been causing trouble), or as a part of a larger adventure or dungeon, Duegar or otherwise. Pgs. 26-27

The Borderlands. An untamed wild region far flung from the comforts and protection of civilization. A lone fortified Keep is the only bastion of Good desperately striving to maintain the forces of Chaos at bay. But Evil is everywhere, lurking in dark caves, fetid swamps, forlorn forests. Bands of cutthroat brigands and ruthless tribes of humanoids eager to clash with the forces of Food rove the region. The Borderlands hold many secret wondrous locations, and opportunities for fame, prestige, and fortune are plentiful. But equally abundant are the perils, risks, and challenges to those brave enough to explore the wilds. Sharpen your swords and axes. Purchase your iron rations and tinderboxes. And Don't forget at least one 10-foot pole. Adventure awaits those with the mettle to confront Chaos in the Borderlands!

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.

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).

When her father goes missing, a young adventurer has no other choice than to gather her friends and head for the city of Loudwater. Soon after she gets swept away in an obscure design threatening to drag the entire region into chaos and war. At the heart of this mystery, lies not only her father, but the long-forgotten history of her once-despised family and a primordial beast influencing events from the shadows, moving her family like pieces on a chess board. Visit www.perfumersdaughter.com for more information. You can also address me directly on The Perfumer's Daughter Q&A on Facebook. All battlemaps and dungeons are free to download for use in digital platforms (such as roll20) on the aforementioned site.

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. Now the heroes will go beneath Wyvern Tor to discover the terror that chased out the orcs and perhaps find the source of the orc’ssardonyx. Journey to Beneath Wyvern Tor is the third of four parts in the After Lost Mine series. It will play out the journey to the orc’s former cave settlement and then into the darkness beneath. Part IV will have the party deal with the terror from the Underdark that drove out the orcs.

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.

Agents of the fire giants of Maerimydra, a city in the Underdark, have overtaken the drow outpost of Szith Morcane. The factions seek out adventurers to free the outpost’s leaders for questioning on the giants’ activities. Can you extricate them before it’s too late?

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

"The Aboleth's Grotto" is a nihileth lair suitable for four 10th-level characters. The adventure can be completed in one session. The small town of Springwell harbors a secret that almost nobody knows about, and those who do conveniently ignore: it sights right over an unoccupied settlement of the deep caverns of the underworld.

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.

Tieflings are raiding a dwarven expedition under a shield of magical darkness, but if the PCs can supply the dwarves with giant scarab beetles capable of generating potent bursts of magical light, they might just survive. Unfortunately, they'll need to escort the herd of giant beetles through the Underdark first. A D&D adventure for 3rd-level characters.

Avalanches are hardly news in Icewind Dale. The frequency to which it is occurring, however, defies logic. What is the cause of this strange phenomenon? What horrors could have unleashed such force of nature with such reckless abandon? Horror Beneath the Frost is a slasher horror adventure set in Icewind Dale, deep within the Reghed Glacier. It features yetis, mind flayers and a boneclaw! The adventure is designed to be easily dropped into: • Any homebrew campaign where avalanches occur. • Icewind Dale: Rime of the Frostmaiden campaign. • Plague of Ancients Seasonal Campaign for the Adventurers League (AL) organized play program. Inside you will find: • A slasher horror adventure optimized for five characters with an average party level (APL) of 8. • Scaling advice for three to seven 5th to 10th level characters. • A printer-friendly version of the adventure. • 4 digital maps importable to Roll20, Foundry VTT and your VTT of choice. Includes gridded, grid-less and printer friendly versions of the maps. • D&D Adventurers League compatible adventure (Dungeon Seed: This Seems Familiar | DC-POA-JL01)

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 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.

While in the peculiar village of Basht, a town full of strange customs and superstitions, an elderly woman asks you to check in on her grandson, a Gondite tinkerer testing out his latest invention in a nearby cavern. Sounds easy enough, right? A Two-Four Hour Adventure for 5th-10th Level Characters This adventure originally debuted as custom content for the 2019 U-Con convention in Ann Arbor, Michigan. Visit them at https://www.ucon-gaming.org/