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

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.

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.

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

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.

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!

The time has come for the brave and the bold to put an end to the machinations of Maerimydra’s demonic occupiers and their fiendish fire giant ruler. This will be no mean feat; the city is a cesspit of corruption and madness. You will have help, however, as an unlikely group of allies have gathered to your side in the Underdark beneath Faerûn. Danger, glory, and redemption await those brave enough to seize it. 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?

Centuries ago, a powerful wizard locked himself in his inner sanctum to dedicate his life to the pursuit of knowledge. His discoveries and magic remain sealed inside to this very day. Solve his riddle and unravel the fate of the wizard Maalzinabar and the sinister evil lurking in the depths. A 2-3 hour adventure for 5th-12th level characters

Explore political intrigue, gene splicing, and a thrilling battle for survival in the Timescape's World Below in DOOM of the DRAGON GRAFTER, a 9th to 10th-level adventure for Draw Steel! You and everyone you know has a story of the dragon who ruined your life. You've lost so much and wondered why it had to be this way. Recently you learned that all these dragons that wreaked havoc on Orden were intentionally created to do so, all as an experiment run by a voiceless talker known as Lord Pulposa. You don't know why he did this, or how you're going to break into his lab. What you do know that you're going down into the World Below after him to make sure his schemes will never hurt anyone again. You are the Doom of the Dragon Grafter. Features: - Over 25 pages of an adventure written by the author of The Workshop Watches and The Fall of Blackbottom (that's me!) - 23 Victories worth of encounters - Lord Pulposa, a level 9 Solo Monster designed by Scott Bullock, guaranteed to terrorize your friends and enemies - Battle Maps & Positioning Maps for most combat encounters - Some Draconian fiction thrown in there for good measure - Shared under a CC-BY Sharealike so you can do whatever you want with it - A Goblin named Spanky

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?

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

Tonight, a ceremony of light is taking place on the surface. Meanwhile, a world away in the city of spiders, a drow matron solidifies a pact with soul-consuming entities who require great sacrifices in trade for unimaginable power. Drow eyes turn to the surface. This book contains a mega-adventure and setting, taking characters across the surface and into the depths of the world. Adventurers will meet unique denizens, battle horrors of the Underworld, explore epic locations, and fight to stop the rise of the drow.

A cave-in at the dwarven mine exposed a passage into the eerie, alien world that lies deep below the surface. Monsters poured out of the darkness and killed many before the surviving miners made it back into the light. Now they seek brave adventurers to face the dangers down in the dark depths. As a one shot or the first adventure of a new campaign, The Eyeless in the Dark carries new and experienced players away from the light of the ordinary surface world and down into the fantastical dark depths where here there be monsters. Chock full of adventure, as well as design notes for Dungeon Masters that will help novice and veteran DMs provide their players with an exciting and memorable game night, and leave them eager for the next session. Use this adventure in combination with the Integrated Hill Encounters and/or the Forest and Grasslands to create an open world sandbox of adventures that can fill many sessions of a campaign.

A strange journey through a living cavern. A request for help to rescue a mining crew leads a group of adventurers into a cave that has seemingly come to life, gripped by a melancholy wave of sadness and memory. In dark caverns where mushrooms walk, vines dance, walls watch, and stones speak, will your band of adventurers become heroes? Or will they be lost within the Mines of Memory? Mines of Memory is a short, 2-3 hour adventure for characters of levels 1-3. It is a delve into a cavern system that has become a Psychic Resonance environment, awakening the caves themselves. PCs will enter to rescue the miners, find the source of the mine’s awakening, and bring peace to a noble creature trapped in its own nightmare.

Expand your game with this collection of 56 NPCs of various Challenge Ratings, thirteen of which include maps and details of their lairs. Add these NPCs as a side-quest, a main villain, a one-shot, a bounty for easy money, or however else you wish. Written by some of the best-selling authors on the Dungeon Masters Guild and outstanding podcasters, each NPC includes an image, a backstory, motives, flaws, and a stat block. Some even include new magic items!

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!

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

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.

She ran. Where to or for how long, she really couldn't say. The little flame of her oil lamp sputtered and went out a few times. She'd snap her fingers and make the wick flare to life, but she may as well have ran blind. The hallways were pitch black with soot and choked with smoke, every turn was a guess and every corridor a gamble. Unnatural screams echoed from every direction. Left, right, left again, was this the south or north end of the labyrinth? She had no idea. The next turn brought her face to face with a doorway completely consumed in blue fire. The room beyond was so bright she had to look through her fingers at it. A shadow covered her, a shape in the doorway: a hulking creature with a wolf-shaped muzzle and enormous pincers for hands, wreathed in the same blue flames. The screams were getting closer behind her, too. They had her cornered, again. The demon slammed its shoulders through the narrow opening, splintering the wood and stone. She dropped the lantern and let the wand in her sleeve fall into her waiting hand. With a word of power and a gesture, she appeared in the familiar bedroom: stuffy and reeking of wood smoke. She'd have to try again tomorrow, if she could remember. During an exploration on the sixth level of Undermountain, a strange invisible creature leads to a series of collapsed chambers that hide a forgotten secret and one of the most devastating forces known to the multiverse. Marambra Nyghtsteel, the forgotten apprentice of Halaster Blackcloak, has been locked away for an age deep within Undermountain. What point and purpose her forced seclusion has, only Blackcloak may know. When a spell consuming blue fire, known as The Spellplague is trapped within the chambers, a series of events have left Marambra, lost in her madness, struggling to survive.

How’d you get here? Let me explain... No, there is too much. Let me sum up. Rescued a retired hero's hapless nephew from goblins at some ruins on a hill Found out that there aren’t any goblins, but spider creatures called chitine instead Uncovered a chitine plot to start a war between the surface world and the drow Got convinced to try to stop that war Got trapped in the caves under the ruins Chased the chitine’s leader, a choldrith, further down into the cave system Nearly got crushed in a cave-in Fought your way through an undead infested mine Nearly got eaten by a colony of chitinous reptiles Picked up the choldrith’s trail and followed it deeper into the earth And now you stand at the entrance to a massive cavern filled with all manner of aggresive creatures. Yep, that about sums it up! And now, here you are, in this giant cavern thousands of feet beneath the surface. All you have to do is pick up that choldrith’s trail again, and manage to navigate the many factions vying for control of this little section of the Underdark. Good luck! And have fun storming the Hollows! This Gazetteer contains: Descriptions of the factions that live in The Shadowed Hollows, a massive cave complex far below the surface The underground city of Naakrasad and the important NPCs that live there Three quests leading to brief adventures within the Hollows for characters of level 4 to 6 7 custom maps of the Shadowed Hollows, Naakrasad, and the quest destinations All necessary monster stat blocks Everything needed to set the scene for the upcoming second chapter of the Into the Underdark Adventure Series