PITCH BLACK - WHY THE UNDERDARK IS D&D'S GREATEST SETTING

🌑 Pitch Black: Why the Underdark is D&D’s Greatest Setting

“The place has many names: the Underdark, Deepearth, the Realms Below, the Night Below, the Lightless Lands. This vast world beneath the surface is home to fabled races such as beholders, cloakers, drow, illithids, and ixzan.” - Drizzt Do’Urden’s Guide To The Underdark

What’s the first thing you picture when you think about Dungeons & Dragons?  Bands of adventurers, dank dungeons full of monsters, majestic and terrifying dragons, bustling taverns, soaring castle spires?? Scratch literally beneath the surface of this fantastical vista and you’ll find the sunless realm of the Underdark; a sprawling lightless "mega-continent" that has defined the game for over 45 years. A kind of D&D version of Stranger Things’ Upside Down but far more deadly.

From its roots in Gary Gygax’s classic Against The Giants/Descent Into The Depths of the Earth/Vault of the Drow/Queen of the Demonweb Pits mega-campaign to its modern dominance as one of the principal settings of the D&D game, the Underdark remains a terrifying place for the unwary and unprepared to tread.

A History Forged in Shadow

The Underdark wasn't built in a day. Its history is a journey through some of the most influential publications in TTRPG history from classic AD&D modules to the Drizzt Do’Urden series of books by R.A Salvatore .

The Greyhawk Origins (1970s)

The concept was born in the late 70s through Gary Gygax. He introduced firstly the Drow (the evil dark elves) as the protagonists behind the uprising of the Hill, Frost and Fire giants in the G series of modules.  The first two modules only hinted at the existence of a hidden power behind the Giants, but by the time the adventurers reached the climax of the Halls of the Fire Giant King, the hidden threat of the Drow was fully exposed with Eclavdra and her tentacled rods!.  In one of our forays against the Giants, Eclavdra actually used the deadly Wand of Viscid Globs against the characters causing utter mayhem and panic. Escaping into the dark passages it was for many a seminal moment where you realised  the "dungeon" didn't end at the bottom of the stairs or in this case the final caverns under the Halls of the Fire Giant King—it went on for thousands and thousands of miles and it was utterly terrifying. 

In D1–2 Descent into the Depths of the Earth, the adventure is less a linear dungeon and more a dangerous Underdark journey meant to wear your adventuring party down before they ever reach D3 Vault of the Drow. The key themes of this introduction to the Underdark are about attrition, alien environments, and foreshadowing the drow threat. 

Before any “set encounter,” the module establishes tone:

• Endless caverns, lightless tunnels, fungus forests and bottomless chasms
• Getting lost is inevitable, running low on food and water is a constant worry, as is the persistent threat of ambush from monsters lurking round every corner, under your feet or above your head
• Wandering monster checks are frequent and punishing, draining your party of hit points and spells in an environment where there’s nowhere safe to rest and recuperate

The key purpose of D1-2 was to teach players that the Underdark itself is hostile, it’s a place where even the most basic of essentials like food and water are scarce, allies are even scarcer and your adventuring party should be completely on edge at all times. You could draw parallels to the famous full page illustration in the Players Handbook of the paladin fighting endless demons in hell, only this time the danger isn’t on some far away plane or layer of the Abyss, it’s miles and miles under the surface of Greyhawk and you are very very alone.

D1-2 also establishes that the drow are not the only race that dwell in the darkness, there are the Kuo-Toa, the strange fish-men who worship Blibdoolpoolp, the Sea Mother.  There are troglodytes, derro, vampires and succubi and the infamous illithids! 

By the time your adventurers reach the threshold of The Vault of the Drow they may have made alliances with some of these races in their quest to defeat the menace of the drow, only to find that The Vault is some kind of twisted version of the City of Greyhawk with rival houses and factions continually fighting against each other for power. D3 The Vault of the Drow establishes the presence of huge cities with the subterranean landscape. Cities that have some similarities to those the players know on the surface world such as a monetary system and trade, but in the chaotic infighting and struggle to become the favoured of Lolth, a city like they have never known before. 

The Forgotten Realms Expansion (1980s–Present)

“The Underdark is a place of survival of the fittest, where mercy is weakness and hesitation is often fatal.” Drizzt Do’Urden’s Guide to the Underdark (1999)

While Gygax planted the seeds, it was Ed Greenwood who watered them in the Forgotten Realms campaign setting. In 1987, the Forgotten Realms Campaign Set officially named this realm the “Underdark."  And if Greenwood watered the seeds, R.A. Salvatore threw on fasting acting fertiliser and heat lamps to grow the setting from the 1990’s to the present day through his novels featuring the Underdark’s most famous son, Drizzt Do’Urden. In turn providing TSR and Wizards of the Coast with material to feature in The Drow of the Underdark, Menzoberranzan boxed set and many more adventures and supplements.

Put simply R.A. Salvatore defined the drow.  Much of what people now consider “core drow lore” comes directly from his novels not the original Gygax modules. His books were massively popular and have sold millions of copies.  The lavender-eyed Drizzt Do’Urden became a gateway character for non-D&D players to get into the game and Salvatore’s books have helped shape the evolution and history of The Forgotten Realms 

Salvatore fleshed out:

• Menzoberranzan as a living, breathing city with its key personalities and landmarks
• Lolth’s matriarchal theocracy and established the Queen of the Demonweb as one of the most recognisable deities in D&D
• The drow’s constant backstabbing, intrigue, and betrayal - think Game of Thrones on steroids
• The role of drow houses, priestesses, slaves, and assassins

“The drow do not conquer by strength alone; they destroy by patience, poison, and betrayal.” AD&D Q1 Queen of the Demonweb Pits (1980)

🐙 It’s Not Just Drow

"The Drow are cruel, yes, but they are still mortal. An Aboleth? An Aboleth remembers the world before the first sun rose." — Vaxlan the Wise, Sage of Greyhawk

It’s easy to assume that given the amount of material that has been produced about them, the drow are the only race to dwell in the Underdark. But the bad news for your player characters is that couldn’t be further from the truth.  The lightless tunnels and caverns are awash with other denizens that could kill you with a single stare, sacrifice you to their insane goddess or at best become a temporary ally when it suits their ends.

“Kuo-toa are degenerate fishlike humanoids that … dwell in madness and everlasting night … At the height of the illithid empire, the mind flayers captured kuo-toa … the prolonged psychic subjugation … had driven them mad … their collective subconscious can cause a god to manifest.”

What makes the Underdark such a magnificent and perilous setting is not only the terrain, lack of light, food and water but the mix of threats to your adventurers.  From the Duergar (Gray Dwarves) the psionic, cruel slavers with a bitter hatred of their surface dwelling relatives and the Derro, the degenerate dwarves driven mad that have become sadistic inventors and torturers, to Kuo-Toa the insane fish-folk these all pose a threat not dissimilar to the drow.  And then there are the apex predators that lurk in the deep..

There are Beholders, the paranoid eye-tyrants that can just as easily kill or subdue your party of adventurers with the rays from one of their many eyes.  They lurk, often in isolation, in the dark corners of the Underdark. There are the fearsome Illithids more commonly known as Mind Flayers, the squid-headed psionic brain-eaters immortalised by Bill Willingham’s painted illustration on the back of the module D1-2 Descent Into The Depth Of The Earth who aim to enslave entire populations and rebuild their inter-planar empire. And then there’s the ultimate Underdark apex-predator, the Aboleths. These huge snail like monsters pre-date most civilisations and lurk in the depths of the sunless seas of the Underdark plotting enslavement and genetic corruption.  They are the Lovecraftian style cosmic horror that everything else in the darkness fears.  

“Oh, most delicious morsel … quiver to be plucked … before inevitable, ardent consumption… Ah, that hits the spot.” — A mind flayer’s own words from lore reflecting their alien and predatory mindset

🏰 Iconic Locations

• Menzoberranzan (Forgotten Realms): The City of Spiders, home of Drizzt Do'Urden and a web of deadly noble houses including House Baenre.
• Gracklstugh (Forgotten Realms): The City of Blades, a brutal Duergar city of forges and tyranny where slavery, paranoia, and psionic power rule beneath the iron grip of the gray dwarvesl.
• The Vault of the Drow (Greyhawk): A massive cavern containing the city of Erelhei-Cinlu, glowing with eerie violet light.
• Skullport (Forgotten Realms): A lawless Underdark port beneath Waterdeep where pirates, slavers, and monsters trade in secrets, slaves, and stolen magic under the shadow of the mysterious Skulls. The Forgotten Realms version of Mos-Eisley.
• Ched Nasad (Forgotten Realms): Once considered the second most prominent drow city in the Underdark, but is now a ruin of web-choked chasms and ghosts, the first great casualty in the War of the Spider Queen.

⚔️ Why the Underdark is the Best Setting

““The passages and caverns of the underworld are filled with creatures which hate the light and seek to destroy all intruders.”  D1–2 Descent into the Depths of the Earth (1978)

The Underdark offers a unique gameplay experience that the "surface world" simply cannot match, put simply it turns the world itself into the enemy.  

In the Underdark, every resource is a victory. Light is a liability that attracts predators, and food is often as dangerous as the creatures trying to eat you. In most settings, danger is optional. In the Underdark, danger is ambient.

"The first time my party ventured down, we were down to one torch and half a waterskin. Every drip and scuttle felt like a direct threat. It was terrifying and absolutely unforgettable." — Elara Sunshield, Veteran Player

In the Underdark, unlike the surface world, there are no safe defaults.  All of the relaibale assumptions players can make about the surface world such as towns and cities being safe havens to retreat to and rest are thrown into the sunless seas. In the Underdark there is no safe place to retreat to, in fact retreating often puts you in much greater danger! The Underdark is full of intelligent enemies where ambushes are commonplace and survival requires strategy rather than a bucket load of hit points and magical items.

🏆 Final Verdict

“There are no shadows in the Underdark. … It is a place … with no room for hopes and dreams.” — Attributed to R.A. Salvatore (reflecting the Underdark’s unyielding darkness and threat).

The Underdark stands the test of time because it represents the ultimate challenge. It isn't just about fighting monsters; it's about surviving an environment that is actively trying to kill you. Whether you are navigating the politics of a Drow house or fleeing an Aboleth's telepathic call, the Underdark provides a sense of wonder and danger that no other setting (possibly Ravenloft?) can replicate. Enter it at your peril……!