"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.

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 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

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

With allies gained from denizens of the Underdark, the former drown enclave of Szith Morcane is on the precipice of being retaken. During the battle for Szith Morcane, secrets of the drow community are revealed. What will you do with this knowledge, and how will it affect the outcome of the conflict?

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?

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).

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!

Rumors of faceless demonic creatures have been steadily rising in the Hillsfar region, and it is said that far below the surface of Faerun, nestled in the bowels of the Underdark, ancient terrors are stirring. The imperiled drow of Szith Morcane have extended an intriguing offer, but can the drow be trusted, and for how long? An eight-hour adventure for 11th-16th level characters.

A mind flayer has called for a massive conference of monsters in the Underdark beneath Hillsfar. Trolls, umber hulks, demons, and more have answered the illithid's call. To infiltrate this gruesome menagerie, you must embrace the monster within yourself.

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

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.

For the most part, the town of Ockney’s Hold has always been a peaceful place—bordering on boring. The most interesting things going on in this frontier mining settlement include the annual livestock fair, the cost of spirits at its various inns, and speculation fueled by those same spirits as to what foul things are being dumped into the river by the ore refinery. Recently, however, the usually placid Baron Reinson has begun to act erratically, ignoring most of his counselors, giving more responsibility to his equally erratic chamberlain, and replacing key figures in Ockney’s Hold with outsiders. With no clear answers as to what might be behind the baron’s strange behavior, his last loyal counselor seeks out a band of adventurers to help. Will these brave heroes be able to get to the bottom of a widening conspiracy? And can they expose the terrible and unseen forces manipulating the baron in time to save Ockney’s Hold? Published by Gamehole Publishing.

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.

A Beholder Love Story A dwarven mineshaft has become the new home of the heartbroken beholder Sindryl. Discover who could be wicked enough to separate Sindryl from his love Prix'am, put a stop to their plot, and restore Prix'am's missing heart. A 3-6 hour Dungeons & Dragons 5th Edition adventure for Tier 2 characters. This adventure includes: 2 New Monsters (including 1 New Beholder!), 3 New Magic Items, New NPCs, a Minecart Skill Challenge, Romantic Random Encounters for the Underdark!

In this small 20 page adventure module, centered around an archaeological dig, revisit Bull Creek and find out the secret behind what really lies in the hero Vertrixx Mazilaxx's sarcophagus. To do so, you'll have to meet up with master archaeologist Geranimus to delve deep into the ground. On the surface, politics boil and tensions between species are high. Below, secrets are to be uncovered. Can your party find the truth? Find out in Old Bones. Old Bones- a 5e SRD adventure for levels 4, 6 and 8. In James Grammaticus' Dungeon Short series, James explores fantasy worlds and settings in short bite-sized one or two shot adventures that be used on their own, can spring off into a larger campaign, or can be used as a side-adventure in a campaign.

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

Save the village of Millvein! Prevent a war with the drow! In this 3-4 hour adventure for 4-5 characters of 2nd level, travel to a small chitine lair to prevent them from destroying the small village of Millvein and inciting a war between the surface and the drow. Includes: A 3-4 hour adventure for 2nd level characters Map of the village of Millvein 2 DM maps Stat blocks for all monsters the players might encounter. See where the adventure began in Into the Underdark - Part 1 A Family Affair The adventure continues in Into the Underdark - Part 3 They Call It A Mine