This material was originally published as two separate adventures, D1: "Descent into the Depths of the Earth" and D2: "Shrine of the Kuo-Toa." Contained herein are referee notes, background information, maps, and exploration keys intended for use with the Advanced Dungeons & Dragons rules. The adventure can be used alone or as part of an extended adventure that begins with G1-3: "Against the Giants" and continues with D3: "The Vault of the Drow" and Q1: "Queen of the Demonweb Pits." TSR 9059

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.

Hellmaw Island is a place of legend, a hidden fortress protecting the greatest treasures in the world. Rumour says it is guarded by wicked traps, bizarre and terrifying monsters, and maddening enchantments. Our heroes have been tasked with penetrating this mysterious stronghold, and they will find it to be stranger and more dangerous than anything they have encountered before. Assault on Hellmaw Island is a 5th Edition Dungeons & Dragons adventure for characters of levels 5-10. It will take 4-8 hours to complete.

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.

Are your player's going fishing in the Underdark? Booked a ride with the Kua Toa Travel Agency? Taking a cruise on the Darklake? Well then Journey Through the Center of the Underdark 2 - The Darklake Strikes Back is just what the Leemooggoogon ordered! Like the first Journey, The Darklake Strikes Back contains several encounters designed with Out of the Abyss traveling days in mind, but easily inserted into any 5th Edition Dungeons & Dragons Underdark setting. Unlike the first Journey, The Darklake Strikes Back has a mid sized three level dynamically defended dungeon, complete with a dragon at the bottom! This complex is right at home on the Darklake but could also readily be inserted into your Tyranny of Dragons campaign as well. Written for a party of characters levels 4-6 with notes included for adjusting encounter difficulties for lower or higher level groups Journey Through the Center of the Underdark 2 - The Darklake Strikes Back should provide 6-10 hours of gameplay excitement!

In the search for allies in the Underdark, you are called upon to travel through the recently opened Waydown sinkhole to find the lost myconid colony of Sporedome. It is said that they once cultivated a strain of mushrooms that could protect one from falling into madness. Can this be the cure for the rapidly spreading onslaught of insanity?

In the Anauroch desert, darkness is growing. The followers of the Vile Spore Goddess Zuggtmoy have stolen the dreams of the Bedine Seeress Deja, trapping them in an eldritch artifact. Unless her dreams are returned, the Seeress will descend into madness, and her people along with her.

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.

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).

Sarkt is an illithid sorcerer. It was cast out of its community for its heretical studies (Sarkt was in fact, lucky to escape alive). It didn't take the cunning creature long to pick up a few thralls and find a new place to live, safe from the murderous intentions of its companions. Sarkt dwells in the subterranean ruins of an ancient shrine to Blibdoolpoolp, the crustacean-headed deity of the kuo-toas. This shrine lies on the fringe of a region controlled by kuo-toas, but since Sarkt's arrival, the fishmen avoid the area. A few unfortunate kuo-toas now serve Sarkt as thralls and maintain the illusion that the shrine serves Blibdoolpoolp. Pgs. 82-88

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

TENTACLES. VERY DANGEROUS. YOU GO FIRST. Adventure in the Underdark, Part Two The colony of svirfneblin, while grateful for the adventurers’ deeds, is still in need of a reliable source of drinking water. The kuo-toa hold the lake, and there is the matter of the tentacled menace the party faced previously… This adventure is a continuation of Tentacles. Why Did It Have to Be Tentacles?, but can be run by itself as well. It is designed to easily fit into any standard fantasy setting. A 4-hour adventure for 6th-8th level characters

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

"Imperial Ghoul Outpost" is an iron ghoul lair suitable for four or five 10th-level characters. This adventure can be completed in a single session. When a clan of duergar prospectors unearthed caverns not on the their maps, they were particularly excited about a strange new iron orc they found there. not long after mining began, undead horrors emerged to attack the dwarves. Only one duergar escaped, his mind shattered by the experience. The Ghoul Imperium continues to explore the area, and it has its own plans for the newly discovered one.

Deep beneath the Isle of Dread, in a place forgotten by the world of light, an ancient, unfathomable evil festers. Within the desiccated ruin known as Golsimorga, the debased kopru servants of Demogorgon work foul rites, steeping immature shadow pearls in pits of liquid insanity. None from the world above have yet fathomed what terrors lurk beneath the Isle of Dread, nor what mad scheme roils to profane life deep within the city's gangrenous corpse. "The Lightless Depths" is the sixth chapter of the Savage Tides Adventure Path, a complete campaign consisting of 12 adventures appearing in Dungeon magazine. For additional aid in running this campaign, check out Dragon magazine's monthly "Savage Tidings" articles, a series that helps players and DMs prepare for and expand upon the campaign. Issue #353 of Dragon features ways to improve the PCs' vessel, the Sea Wyvern, as they take their adventures back to the seas. When the PCs journey deep under the Isle of Dread to find the source of the shadow pearls, they discover horrors beyond imagining in a haunted underground city perched on sanity's razored edge. Pgs. 28-66

Peren, a guildless Devkarin collector of obscure relics has gone missing. The elf of shadow is in deep debt to the Orzhov as well as to the Rakdos performer, Ophyira. To discover Peren’s fate the party must descend into the Undercity of District Four, within the territory of the Golgari Swarm. Continuing the story which began with Off to a Weird Start, and picking up where The Palace of Pain’s Pleasures left off, this adventure is designed to be part of an ongoing campaign. For Dungeon Masters who wish to incorporate The Felicity Triskelion independently from the ongoing story, 10 Adventure Hooks (one for each guild) are included, giving The Felicity Triskelion flexibility for one-shot play or for inclusion in your own campaign!

This is a trapped corridor which can be dropped into any castle, dungeon, ruin or underground adventure. It features full rules on how to scare the living be-jesus out of your adventurers and have sone great fun with them too. Get ready... as the 'Umber Eyes' is ready to receive you...

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.

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!

A fast-paced one-shot from the bestselling author of The Secrets of Skyhorn Lighthouse! A shadowy force gathers inside the abandoned halls of Lastwatch Keep. Can the players defeat the drow invaders before they escape to the underworld with sinister intelligence about the surface? Shadows of Lastwatch Keep is a one-shot adventure for four or five 4th-level characters. It takes about 3-4 hours to complete and includes: -A drow strike team desperate to escape the keep’s surprise foe -A new monster, the drow commando -Combat cards for each monster, PC, and special treasure -A beautiful, hand-drawn map by Jake from Beware the Wizard