From the magazine: "The monster you're sent out after is so dangerous that even mind flayers fear it. And the illithids want your help!" Earthquakes hit the area around Needlespire mountain, affecting both dwarven and deep gnome villages, and the local mining industry. Deep gnome expeditions discover an illithid outpost! This adventure includes roleplaying encounters with both deep gnomes and illithid in their quest for the true cause of the earthquakes. The creature causing the earthquakes is a draknor which has sent its huge tentacles into the earth seeking magma to fuel its growth. Pgs. 38-60

The Fate of Faerûn Lies in Shadowy Darkness! Daggerdale is reeling from a sudden series of murderous drow raids. As a grave threat to the entire surface world develops in the war-torn dark elf city of Maerimydra, intrepid heroes must discover its source and destroy it, if they can.

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.

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.

In this adventure, the Lord Commander of the Sharn Watch hires the heroes to investigate the murder of an actress. The investigation quickly spirals into a bloody dispute involving a dead wizard’s spell-book, political rivalries, and secrets that might foment war among the Five Nations. Pgs. 1-37

In Prisoners of the Drow, a band of adventurers storm a drow outpost, confront the drow mage in charge of it, and rescue prisoners held within. The heroes must bypass traps and devious defenses to reach their goal and accomplish their mission. The adventure is designed for a party of five adventurers between levels nine and twelve. It features: Encounters by Level - Varying types and quantities of creatures are suggested based on the party's actual level, allowing each encounter to present the appropriate challenge to the party. Encounter Notes - Suggestions for how to run combats are provided for game masters who place an emphasis on engaging, tactical battles. Inciting Action - Suggestions for ways to present the adventure to players are provided. Ease of Use - The format and style of the document allows the game master to find information quickly while running the game at the table. Detailed Maps - What's an adventure without maps? Not much else to say here. This adventure is designed as the first in a two-part series. The second adventure Into the City of Spiders takes the adventurers into a drow compound far from the surface. https://www.drivethrurpg.com/product/247674/Into-the-City-of-Spiders

The Zhentarim ask the party to investigate what happened in one their most important underdark outposts. If the party accepts, they'll have to deal with maddening darkness, grimlocks, an insane kenku assassin and unpredictable mixtures of potions. A short, fun dungeon romp that is easily adapted to other settings and other patrons. The combination of utter darkness and a villain based on sound makes for fun shenanigans on the side of the DM. Feasible as a one shot for an efficient party. Two tendays ago, Zhentarim agents were to transport a shipment of rare potions between their Underdark outpost and the surface world. The shipment has yet to arrive, and the outpost is not responding to any sending spells. Growing worried, the outpost’s overseer sends a group of hireswords to investigate and return it to Zhentarim hands. This particular adventure deals with the delusions of madness of Fraz Urb'luu. It also features Muurmic, the mad kenku first described in the December 2015 issue of Dragon+.

Troubles simply mushroom in the Underdark. The alchemist would like some fungus and spores, but no one wants to get them. Perhaps you could help. The adventure begins with the party finding a caravan. In addition to being able to trade with these NPCs, the party also can be hired by an alchemist to bring bag some red fungus and some Myconid spores from underground. Underground, the party will have a chance to interact with friendly Myconids and venture through a large labyrinth of passages (this labyrinth isn't mapped and is dealt with through storytelling, random encounters, and roleplay). The adventure culminates in a battle between the Myconids and Flinds, and the players can participate. Pgs. 4-12

A band of evil fey, led by a corrupt bralani, has raided an eladrin city and kidnapped several respected elders. The fomorian king claims the rogues don’t act on his behalf, but the eladrin city threatens the fomorians all the same. To prevent war, the PCs travel through the Underdark of the Feywild—a wondrous place filled with the beautiful and the horrifying—in search of the evil fey and their captives. Pgs. 96-101

Side-Trek adventure When your PCs gain access to the teleport spell, their whole world changes. That simple spell opens up instantaneous, long-distance travel. No more long overland journeys or dangerous retreats through hostile territory. All it takes is clasped hands and a word from the wizard, and poof! The PCs are where they want to go. Except that it isn’t that simple, because teleport isn’t foolproof. The off-target teleports are a matter of scattering your PCs someplace else on the map and forcing them to get their bearings and make the long overland journey anyway. But this Side Trek focuses on the really intriguing column on the teleport chart: “similar area.”

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

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.

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.

Waves of supernatural darkness sweep over the subterranean city of Stoneholme, quenching lights and bringing with it foul creatures of shadow. After heroically defending a group of dwarven children being ravaged by a group of these shadow beings, the PCs are approached by Shtawn Deppenkhut -one of the king's own advisers- and are offered the task of finding the source of the darkness that threatens the city. The PCs investigation takes them through the Underworld to hidden caverns, where demon worshiping priests offer living sacrifices in an attempt to plunge Stoneholme into everlasting darkness, a first step in destroying the hated city once and for all, but as it turns out the priests aren't the only ones behind this unfolding plan to destroy Stoneholme. Dark Days in Stoneholme is ideally suited for a group of dwarven adventurers. It is recommended that you have access to the Stoneholme section of the Rise of the Drow revised & expanded edition (2014) but it is not necessary to run the adventure. Also available for Pathfinder. Published by AAW Games.

The Adventurers arrive at a drow outpost in the Underdark. They must either dispose of the drow or ally with them against the invading legions of Orcus!

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.

Originally designed as a convention module, this adventure sends the heroes into the underdark to do battle against the mysterious denizens of the deep! A drow housemistress commissions the characters to acquire a mysterious weapon known to be in the hands of her dark elf enemies. Locating, identifying, and acquiring the magical weapon leads the heroes on a great trek across the underdeep, where they must battle svirfneblin, a powerful lich, and enemy drow. This adventure us specifically designed for play by drow characters, but can be used with any adventuring party. Pregenerated drow characters are included.

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.

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

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