In the city of Waterdeep rests a tavern called the Yawning Portal, named after the gaping pit in its common room. At the bottom of this crumbling shaft is a labyrinthine dungeon shunned by all but the most daring adventurers. Known as Undermountain, this dungeon is the domain of the mad wizard Halaster Blackcloak. Long has the Mad Mage dwelt in these forlorn depths, seeding his lair with monsters, traps, and mysteries—to what end is a constant source of speculation and concern. This adventure picks up where Waterdeep: Dragon Heist leaves off, taking characters of 5th level or higher all the way to 20th level should they explore the entirety of Halaster’s home. Twenty-three levels of Undermountain are detailed herein, along with the subterranean refuge of Skullport. Treasures and secrets abound, but tread with care!

The slave markets of Katapesh may be an unsavory sort of business, but the trade metropolis’s enigmatic law enforcers have few qualms with the legal act of selling and buying flesh. Other factions, including the abolitionist Eagle Knights of Andoran, have their own opinions on the matter, however, and frequently send undercover agents into dangerous territory to break up slave rings. When one such Eagle Knight goes missing while investigating an underground slave operation beneath the dilapidated Twilight Gate district, it’s up to the PCs to delve an abandoned (but hardly uninhabited) qanat beneath Katapesh and discover her dire fate. Yet not everything is as it seems in the dank slave caverns under Twilight Gate, and clues hint that the slavers may have even more loathsome connections than initially suspected.

In this adventure, the PCs discover that not all souls rest easy, particularly those spirited away to Nightwyrm Fortress. To learn the truth, players must pierce death's veil itself and enter the Shadowfell, where sinister echoes of life wing through eternal gloom. This adventure can be run as a stand-alone adventure or as Part Three of a three-part series of adventures (starting with P1 King of the Trollhaunt Warrens(TM) and P2 Demon Queen's Enclave(TM)) that spans 10 levels of gameplay.

The Dread of Dynwel is an adventure set in the Forgotten Realms and optimized for 4-5 players. The characters start as a down on their luck but somewhat experienced crew of adventurers with a wanted poster which pays a much-needed gold reward. Soon, events in the Sunset Vale are revealed as more dangerous than they seem, sweeping the characters along with them. From the heights of the Sunset Mountains, the alleyways of Scornubel, and depths of the Reaching Wood: The Dread of Dynwel covers levels 2 through 8 and features material which can be played as a full campaign or dropped into an ongoing one.

A town in Falkovnia finds itself stuck in a time loop that repeats the final hour before it is overtaken by a legion of undead. Only the PCs and a mysterious crone are able to remember the events of each cycle. The heroes must find a way to prevent the destruction of the town and stop the cycle of death!

In the Yatil Mountains south of Perrenland there is rumored to be a magical hoard of unsurpassed value, a treasure of such fame that scores of adventurers have perished in search of it. Find the perilous Lost Caverns of Tsojanth and you may gain the hidden wealth of the long-dead arch-mage-- if you live. Module S4, this contains a brief wilderness journey to the caverns, but the bulk is underground. The caverns are noted as a previous lair of the Arch-mage Iggwilv- though she is long gone, her Demonomicon remains. This module marks the first appearance of several monsters and items that would later appear in the Monster Manual 2 and Unearthed Arcana. A labyrinth features in the caves. TSR 9061

For over a thousand years the things that lurk beneath the waters, skulk in the darkness and lie hungrily in dank crypts have been patient, while all around them men and monsters bicker amongst themselves, bold enough to traverse the dark caverns' depths but afraid or perhaps wise enough to leave the forgotten vaults and hidden passages alone. Beneath the lost ruins of ancient Thracia lie the vast caverns of a once great civilization. While a death cult rules the surface, the Minotaur King and his beast men lurk fall below. Descend even deeper into the darkness and discover a lost and arcane world that waits for those brave enough to enter! Necromancer Games and Judges Guild have teamed up to expand and update the classic module Coverns of Thracia for 3.5. Designed for characters of 3rd to 8th level and higher, the Caverns of Thracia is a mini-campaign setting that presents intricate plots and exciting adventures.

Captain Brunswick’s Manor is a dark, dream-infused adventure where players unravel the mysteries of a haunted noble estate. As they navigate twisted corridors, confront eerie foes like the Dreamborne Wyvern and Auntie Sol, and face mind-bending trials in a nightmare-filled dream realm, the party must find a way to free Captain Brunswick and his daughter from their cursed slumber. With multiple routes through the manor and unique magical rewards, this adventure offers both intense combat and chilling roleplay. Boss Fights: Engage in memorable battles against Captain Brunswick, the Dreamborne Wyvern, and the malevolent Auntie Sol. Puzzle Encounters: Solve challenging trials that mix dream and reality, testing both wit and strength. Legendary Weapon: Unlock Tulva, the Tide Bringer, a powerful magic weapon that evolves with its wielder.

Gray Mountain lies deep in the lush elven forest. The temple there was a haven of meditation and learning - until taken over by an evil cleric known as the Rahib. Far under the mountain, he paces before the temple's great altar. A brown-robed servant rushes in and falls to his knees, trembling at the sight of the Rahib's black panther. "Rahib, adventurers came to the village as the sun rose - the strangers now protect Rahasia." A scowl crosses the Rahib's face. "I must have Rahasia! Attack again tonight." As the servant scurries away, a deep growl rises from the giant cat. Gripping the panther's leash, the Rahib paces again, speaking out loud. "We must dispose of these strangers quickly; the secret beneath the temple will not wait much longer." Note: the setting is unspecified, but certain tie-ins, like the wines, prefigure Ravenloft. See: https://twitter.com/chrisperkinsdnd/status/703751906703749120 TSR #9115

The lost city of Archaia - an ancient ruin sunken into the earth - lies deep in the badlands. In recent years, caravans from Eastdale have come under attack from orcs, goblins, and worse. Some say these blood-thirsty warbands have made lairs in the deep caves and ruins. Sill others say the ancient halls are filled with magnificent treasures left by the Archaians. Are you brave (or foolish) enough to delve The Forbidden Caverns of Archaia? The Forbidden Caverns of Archaia (FCoA) is a 296-page classic megadungeon for use with any old school fantasy role-playing game. The pages of Forbidden Caverns are crammed full with new material, maps, amazing art (including special surprizes by former TSR artists), as well as an amazing colour cover art by Ex-TSR artist Erol Otus that matches Barrowmaze Complete as a sister-book. The Forbidden Caverns of Archaia will keep your players on their toes and your campaign going strong for years. FCoA is brought to you by the Old School Renaissance (so don’t forget your 10’ pole).

A new megadungeon from Three Castles Award Winner (2018) and Barrowmaze author Dr. Greg Gillespie! HighFell: The Drifting Dungeon is a 246-page classic megadungeon for use with any old school fantasy role-playing games/clone. The pages of HighFell are crammed full with new material, maps, and art, including a colour cover by Ex-TSR artist Erol Otus (that matches Barrowmaze Complete and The Forbidden Caverns of Archaia as sister-books). HighFell: The Drifting Dungeon will keep your players on their toes and your campaign going strong for years. HighFell is brought to you by the Old School Renaissance (so don’t forget your 10’ pole).

The whispered worries grow more fanciful and terrifying by the day... where has the loremistress gone?... what's wrong with the master smith?... who-or what-stalks the marketplace?... The questions need answers, and heroes are needed to do the asking! But the only thing worse than what hunts the mist-shrouded streets is what lies beneath them... Adventure in Dun Eamon: Demons roam the streets of the city of Dun Eamon, criminals rule the night and an important local power figure has gone missing. Can your heroes unravel the clues that lead through every social element of the city, into the hearts of its inhabitants and far below its streets in search of answers? Or are some mysteries better left unsolved? Uncover An Artifact: The Grey Citadel is a mini-campaign of urban detective work and dungeon exploration designed for four or more characters of 5th level. Set in a rain-soaked, rough-and-tumble frontier city, The Grey Citadel offers numerous colorful NPCs, a richly unique location, new monsters and magic items plus enough plot twists to provide hours of role-playing and door-kicking adventure where your wits must be as sharp as your swords!" This adventures mixes dungeon crawl with city investigation, keyed encounters and timed encounters.

This deluxe adventure takes heroes into the ruins of Gardmore Abbey, a monastery that was once the base of a militant order of paladins devoted to Bahamut. According to legend, the paladins brought a dark artifact back from a far crusade and stored it in their abbey for safekeeping, and evil forces gathered to assault the abbey and take it back. What the legends don’t tell is that this artifact was actually the Deck of Many Things, a force of pure Chaos. This adventure brings characters into the extensive dungeons beneath the ruins - dungeons that are warped and twisted with the raw forces of Chaos surrounding the cards of the deck.

Anea, the Amazon queen, and her warriors have helped neighboring king Eriklius defeat the usurper Todeuclis. When king Eriklius ascends the throne he covets the hand of Anea, but she refuses. In a fit of rage he sends his warrior Euclatis to destroy her palace and the surrounding town of Gythaclea. Anea—gravely wounded—pleads with Nyx, Greek goddess of the night. She asks for the power to take revenge. Her plea is granted, at the cost of being turned into a medusa. As rumors spread that Anea is still alive, the heroes are sent by King Eriklius to retrieve her. It seems an easy mission, but they soon discover all is not as it seems... Pgs. 157-163

Far north of the Denali homeland is the Archipelago of Tyr and home to dangerous seafarers. Tyr is well-known as the land of the Minotaur that does allow some foreigners to visit albeit with less than perfect hospitality. Originally used as a one-shot with the Denali campaign characters, King Pellet sent the party north to investigate a trade deal and look into reports of some type of incendiary weapon…

For 1000 years, the Pyramid of Amun-re has lain undisturbed. Now the ghost of the once-great Pharaoh pleads with adventurers to venture into his tomb, foil the devious traps within, and free his soul. A classic dungeon crawl, with mazes and quality lore. No one has ever returned from the tomb of Amun-re: his Star Gem must still lie unclaimed! You will need all your cunning, imagination, strength and magic -- just to survive! TSR 9052

A shadow from the past, the Ghost Tower of Inverness has loomed ever larger in the mind of the great Seer of Urnst, Now he has convinced the Duke that an expedition should be organized to go to the ancient keep and recover its greatest treasure — the fabled Soul Gem. TSR 9038

Nearly 100 years ago, Lord Eriador wrested the lands from the hands of evil and began a reign of unsurpassed courage, wisdom, and might that lasted over three centuries. One day this great man of valor was called onward to continue his battle for freedom and goodness on a higher plane of existence. Leaving the responsibilities of rulership to his faithful overseer, he donned his magical shield, helm, and sword and traveled to the Holy Maountain of Anduin to meet his destiny. Eriador left the overseer with this solemn promise: if there ever arose a time of great need, he would answer a summons from the Mountain of Anduin to come back to vanquish any evil that dared to oppress his people. It is now the reign of the third overseer. For years now, an evil mage has been plaguing the land by sending forth hordes of evil humanoid minions to oppress the people. The overseer has been forced to pay tribute to the mage to protect his people. Life has become nearly unbearable for his subjects. It has been over five years since the mage desecrated the holy mountain by placing foul creatures in its depths to guard against the possibility of the people seeking help from their nearly forgotten champion. A fortnight ago, your party was gathered in a secret council chamber to meet with the overseer himself. You felt a spark of hope for the people of this land as the overseer told the legendary tale of Eriador. He gave you the equipment you need and charged your party with the task of venturing into the heart of the now monster-infested Mountain of Anduin to call back the people's great hero, Eriador the Paladin. Although the three parties sent before you had not returned, ridding the of the land of the mage seemed worth any risk, and you eagerly set out on your quest. Now, standing before the defiled mountain, you wonder if perhaps you were too hasty.

The country of Rhyl has been beset nearly every night for many years by a large, terrible creature that flies out from the mountains near the city of Asereht. Nearly a year ago the creature broke through the wall of King Namreh’s castle and carried off the king’s son, Prince Laechim, along with a large amount of the royal treasure. After the creature’s raid on the castle, King Namreh ordered his army to search the mountains and discover Astylis’ complex. The soldiers made two forays into the mountain wilderness, but each time were harassed and eventually driven back by goblin raiders. Since the failure of the second assault, the king has taken to commissioning small parties of mercenaries and adventurers, sending them into the mountains with promises of great reward upon the completion of the rescue mission. For reasons which the king has never found out, none of these rescue parties has ever returned to Asereht. Your party is now attempting to be the first. Pgs. 37-44

A Planescape adventure for 4-7 PCs of levels 9-12 (about 60 total levels). While the module begins in the planar city of Sigil, most of the action takes place in Vudra, a layer of the Abyss. The PCs start in Sigil, tasked to find a vanished brother, and the trail leads to Vudra where the layers demonic ruler gathers magical blades for a terrible vengeance plot. Pgs. 32-58