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).

Undermountain: The Caverns of the Many-Legged is an adventure detailing a hidden mini-level for Dungeon of the Mad Mage for characters of levels 12-13. It uses some of the story and lore of that book, but it can be incorporated or dropped into any setting or homebrew campaign. In a hidden part of Undermountain, former slaves feed their fat, monstrous queen who is fixated on revenge. A broken drow house has finally found a place to call home – only to become abominations. And a massive beast slithers, hunting for anything to satiate its hunger and quell its madness. Welcome to the Caverns of the Many-Legged. Which side, if any, will adventurers choose as they explore this hidden mini-level for Dungeon of the Mad Mage? In this adventure, you will find: a mini-level that can be easily incorporated into Dungeon of the Mad Mage a vivid cast of unique monsters and NPCs, including chitine warriors, a choldrith queen, a spellcasting draegloth, a mad yuan-ti anathema, and others (stat blocks provided for all creatures not in the Monster Manual) locations that could be used or adapted elsewhere, such as a chitine colony and a drider-controlled drow fortress a combination of roleplay, exploration, and combat encounters

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

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

If absolute power corrupts absolutely, Matron Maelora best beware; her plans for total domination of the Underworld are already close to satisfactory completion, while attacks on the Upperworld have become increasingly successful. The other power-hungry drow families of Holoth may despise her but they know a true leader when they see one, and House Gullion has been revealed as the family to lead them all on the path to glory. With the entire Underworld in chaos and the Spider Goddess regularly communing with her chosen Matron, far greater dreams than mere regional conquest are within the grasp of the drow, as Maelora prepares her grand dark elf army for victory! With other mystical allies standing firm with the Matron, other Underworld races beneath her heel or cowering behind fortified walls, and every drow ready to play their part when she gives the word, what could possibly stop her from achieving her final triumph and fulfilling her destiny? But even the greatest of plans has a flaw if you look hard enough, and a party of stout heart and strong resolve can make a difference. At first, such a party may well believe it is on a smaller adventure, perhaps to win a few baubles or some small acclaim by rescuing a few kidnapped villagers. Soon, however, those adventurers will realise that much more is at stake, and that they are the ones who will need to make moves against the evil Matron Maelora and her increasing dominance if both the entire Underworld and Upperworld are to be saved. But how will they go about it? Can they ensure their own success when an entire city is standing against them? Only they have the chance to halt the Rise of the Drow! Published by AAW Games.

A special underworld encounter from DUNGEON Adventures! The toll may be higher than you can afford... To travel further into the Underdark the party must cross a bridge spanning a deep chasm. But to cross, they must pay the toll, or risk another route. Pgs. 47-54

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.

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.

Agents of the fire giants of Maerimydra, a city in the Underdark, have overtaken the drow outpost of Szith Morcane. The factions seek out adventurers to free the outpost’s leaders for questioning on the giants’ activities. Can you extricate them before it’s too late?

Hunt for a Legendary Treasure! Deep beneath a peaceful valley lies the vault of the legendary drow adventurer Larin Karr. Rumor has it Larin Karr has gone, but his vast treasure acquired from years of plundering hordes in the Underdark still remains. Can you find and loot the impenetrable vault? The Vault of Larin Karr details Quail Valley, its residents and monsters, and the twisting tunnels of the Underdark that stretch beneath it. The Vault of Larin Karr takes PCs from 4th to 9th level, during which time they fight dragons, find a missing statue for a band of renegade elves, save the village of Pembrose from scheming hobgoblins, and explore the Underdark and its many dungeons - including the legendary Vault itself! Contains new monsters and magic items! 2003 ENnie Award Silver Winner: Best Adventure

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.

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

More than a hundred years ago, Delbera Axebringer—a mighty warrior and dwarven leader—slew the necromancer Audalot Karexin, but spared his young apprentice Zohir. In the ensuing decades, the bitter survivor brooded and plotted her revenge. Now, descendants of the Axebringer clan are vanishing, dragged screaming into the darkness by the animated bodies of their fallen kin. The Axebringers and their hometown of Davarn need heroes to break this family curse. What mysteries lie sealed within Delbera Axebringer’s ancient abandoned fortress? And what challenges lurk along the Blighted Path winding through the Darklands beneath Golarion’s surface? Down the Blighted Path is a deluxe adventure for 5th-level characters, and includes 64 action-packed pages of exciting battles, supernatural mysteries, and monstrous foes, plus a gorgeous double-sided poster map featuring an overview of the dwarven trading post of Davarn and a miniatures-scale battlemap! The author of this adventure, Monica Marlowe, was the winner of the 2015 RPG Superstar contest, in which hundreds of unpublished authors competed or the chance to write a Pathfinder Module. In addition to her adventure, this book contains a host of new monsters and magic items designed by the contest’s runners-up. Players can expect to reach 7th level upon completion of this adventure—if they can survive its deadly haunts, Darklands horrors, and furious villains both living and undead!

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+.

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.

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

Written by the setting’s creator, incomparable RPG author Monte Cook, Ptolus: Queen of Lies is an action-packed fantasy adventure painstakingly re-designed for Ptolus: Monte Cook’s City by the Spire. Involving numerous challenging scenarios for characters of 11th level, Queen of Lies is filled with dozens of dark elf personalities, cunningly showcasing their alien culture—a world of merciless betrayal and sinister lusts. Deep below the surface, in the sunless lands of the Netherdeep, creatures of darkness build weapons and amass armies, dreaming of invasion. An attack on a peaceful elven shrine in Emerald Hill sends the heroes on a quest to retrieve stolen artifacts and kidnapped friends. All signs point to the actions of the dark elves of Ul-Drakkan, far below the city of Ptolus. However, even within that ancient fortress, there exists a deeper darkness.... Underground enemies lurk beyond every twisting passage, and strange creatures abound. The foul culture of the dark elves is both decadent and cruel, and the heroes may discover that they’ve stumbled into a web of deceit and treachery spun by the self-styled queen of the dark elves. Can the player characters complete their mission without being discovered, or will they find out, perhaps too late, that their actions been orchestrated all along by the wicked Queen of Lies? Published by Fiery Dragon Productions

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.

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.”