As a member of a bold party of adventurers, you and your associates have trekked far into what seems to be a whole underworld of subterranean tunnels -- arteries connecting endless caves and caverns which honeycomb the foundations of the lands beneath the sun. Your expedition has dogged the heels of the Dark Elves who caused great woe and then fled underground. This module can be played alone, as the conclusion to module D1 & D2: "Descent into the Depths of the Earth," or as the third module in a series that forms a special extended adventure (G1-G3: "Against the Giants"; D1-D2: "Descent into the Depths"; and Q1: "Queen of the Demonweb Pits"). TSR 9021

TENTACLES. WHY DID IT HAVE TO BE TENTACLES? A colony of deep gnomes have had their main water source taken over by a group of kuo-toa, but are the fishy folk really the ones to blame for leaving the gem-loving svirfneblin thirsty?… This adventure was originally made for a West Marches campaign, but is designed to easily fit into any standard fantasy setting. There are many areas to insert plot hooks for your own world or campaign. A 4-hour adventure for 5th-7th level characters by ALAN TUCKER

What elder evils lurk in the depths of the freezing mountain ruins? Find out in The Stoneheart Ruin! The adventure features: An adventure set in a desolate, wintry mountain landscape. 16 pages full of intrigue and mystery, containing full color maps, plus 2 unique monster stat blocks. Provides a great introduction to Mind Flayer lore and mythos for Tier 1 players. Can easily be set in the Spine of the World for use in Rime of the Frostmaiden. Let your characters test their mettle as they climb and face the ancient dangers lurking in the cracks of The Stoneheart Ruin! “I have no explanation for any of these finds. We heard disturbing noises coming from further within the mountain; thunderous and growling.” Excerpt from a pamphlet, signed: “Koralia Meadring, Anthropologist Extraordinaire” Koralia needs you to investigate her most recent discovery: a ruined cavern deep in the mountains. Her small team of academics did a cursory walk-through and think they've found a big breakthrough! However, they left in a hurry after being frightened by the horrors they heard coming from deeper in the mountain. They escaped and found one of their team was missing - a goliath named Marek. You must climb the mountains and locate the ruin, make certain that it is safe for study by Koralia’s team, and if possible, find and rescue Marek, whose fate is uncertain. Made during the November 2020 RPG Writer's Workshop.

"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.

The waters of a sunless sea meet a pebble-strewn shore, beyond which opens a wide Underdark vista shimmering with pale cave-light. Titanic columns as big as castles march miles into the misted distance. The wide, steeply sloping base of the nearest colossal column is carved with streets, walls, and elaborate structures, many with gaping, empty windows. A few glimmer with faint illumination. Are you brave enough to explore the spire-city and face the terrors that lurk within? Part 2 of the Barrow of the Forgotten King series. Followed by Fortress of the Yuan-ti.

"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.

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)

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

A strange journey through a living cavern. A request for help to rescue a mining crew leads a group of adventurers into a cave that has seemingly come to life, gripped by a melancholy wave of sadness and memory. In dark caverns where mushrooms walk, vines dance, walls watch, and stones speak, will your band of adventurers become heroes? Or will they be lost within the Mines of Memory? Mines of Memory is a short, 2-3 hour adventure for characters of levels 1-3. It is a delve into a cavern system that has become a Psychic Resonance environment, awakening the caves themselves. PCs will enter to rescue the miners, find the source of the mine’s awakening, and bring peace to a noble creature trapped in its own nightmare.

Tonight, a ceremony of light is taking place on the surface. Meanwhile, a world away in the city of spiders, a drow matron solidifies a pact with soul-consuming entities who require great sacrifices in trade for unimaginable power. Drow eyes turn to the surface. This book contains a mega-adventure and setting, taking characters across the surface and into the depths of the world. Adventurers will meet unique denizens, battle horrors of the Underworld, explore epic locations, and fight to stop the rise of the drow.

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.

Under the Flooded Forest grows a toxic maze of magical fungi called the Nidus. From this horrid realm a cult has struck a terrible blow against the wood elves struggling to regrow the trees in the forsaken swamp of the Flooded Forest. The elves, on the brink of extinction, need the adventurers to navigate this deadly labyrinth and recover a precious object. But the tunnels here crawl with spore-laden beasts and demons, and the very air itself is poisonous.

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 Nexus spore is an intriguing Underdark adventure that can be sewn into any subterranean setting. This one-shot production was designed with long campaigns in mind, for when you want to break up the narrative to keep things fresh and interesting. This short adventure is ideal for players of level 5-7, although, much like the length of the adventure, it is easy to adjust. The adventure fits well into a single long session, or 2-3 short sessions. It comes complete with maps, stat blocks, boxed descriptions and a rare magic item.

Of all the inhospitable domains in the RAVENLOFT@ campaign world, Bluetspur is the cruelest and most gruesome. Nothing grows in the endless night, and lightning periodically falls like rain. The only place to escape those storms is inside the mind flayers' complex under Mt. Makab, but that is the last place where any sane person would want to go. The High Master Illithid has been hatching black plots by hatching vampiric mind flayers in his laboratories! His prodigies are horribly insane, but if he can complete his plans, he will achieve a new level of dark immortality. A pair of heroes has stolen the key to his success, but they have paid a heavy price for their bravery and are in desperate need of aid unlooked for. Meanwhile, the Lord of the Realm watches over the proceedings and plays havoc with the wits of both sides, sapping strength and will with all-powerful thoughts of darkness. A party of adventurers will need all of their skills to escape this black domain without the loss of life, power, or sanity! Enter now the perpetual twilight realm of Bluetspur, home to mind flayers, a land of relentless nightmares. There's no rest for the wicked or the good in this domain. Once caught within the borders of this desolate land, the characters must complete their mission without delay or lose their minds and become slaves of the Lord of Bluetspur. TSR 9264, from 1992

A dwarven expedition has stopped in Mulmaster for much-needed supplies. Furgis Boltsmelter, their founder and leader, is looking for some “no questions asked” protection for the duration of his stay in the city. Whatever he is trying to protect may not stay hidden for long. Can you keep his secret treasure out of the wrong hands? A four-hour adventure for 1st-4th level characters.

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

From the backcover: "Once a generation, they say, a strange comet appears in the sky overhead and the gates of Firestorm peak swing open, (twenty-seven years ago, your father led his band of adventurers into the mysterious mountain, never to return. Now the Dragon's Tear once more flickers in the sky, and the glass gates on the mountainside beckon. Will you pass through to discover the secrets that await beyond the portal none has ever dared and returned? The Gates of Firestorm Peak is the first adventure designed especially for use with the new rules presented in the three PLAYER'S OPTION books: Combat & Tactics, Skills & Powers, and Spells & Magic. While it can also be played using just the AD&D® game core rules (the Player's Handbook and the DUNGEON MASTER® Guide), this adventure offers a perfect opportunity to experience all the potential of the new optional rules. One of the highlights of this package is the first PLAYER'S OPTION player character record sheet. To meet the challenges of Firestorm Peak and escape with their lives, heroic adventurers must battle dark dwarves in their underground city, explore the abandoned caverns of the Elder Elves, and deal with weird alien entities from Beyond. Their goal is to stop the Master of the Twisted Caverns and his dark minions from completing his sinister plot before it's too late . . . if they can. Included in this product are a 96-page adventure book detailing the dungeon that lies beneath Firestorm Peak, 4 full-color poster maps detailing all the important locations in the complex, and a sheet of 56 counters for use with the tactical maps in major combats."

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)