Megadungeons are dungeons so large and complex, an entire D&D campaign could be played within them. They are multi-leveled architectural monstrosities filled with dozens of passages leading up to previous levels or down to lower chambers. These multiple points of connection created a savage labyrinth that made navigation as great a challenge as fighting monsters or outsmarting traps. Adventures like The Temple of Elemental Evil were once the stuff of legend. Defeating Zuggtmoy in the adventures’ eponymous temple was nothing short of a badge of honor for old-school D&D players, for not only did they have to defeat hundreds of powerful monsters to reach her, they had to meticulously map out a multi-level dungeon filled with confusing, criss-crossing architecture.
There’s a stereotype about megadungeons—perhaps wrongfully inspired by hack ‘n slash dungeon crawler video games—that megadungeons are all about monster slaying and treasure gathering. Over the past few decades, megadungeons have fallen out of vogue as more and more people have begun playing D&D for the stories they can tell with their friends, and not exclusively for the thrill of killing monsters and looting their lairs.
This stereotype is false. Or at least, it can be false. If you started playing D&D because you loved the storytelling of Critical Role, The Adventure Zone, or other story- and character-focused streams or podcasts, you may have noticed that these shows rarely delve into large dungeons, let alone campaign-sized ones. At first, I thought this was because megadungeons just aren’t good for storytelling. It’s all monster fights and no roleplaying, no story, no stopping giant monsters from destroying your village and going on grand world-spanning quests. You’re just trapped in a dumb underground maze for a whole campaign.
Turns out, I was wrong.
Just a taste of a single level of the massive Temple of Elemental Evil.
Storytelling in a Megadungeon
Stories of heroes, thieves, villains, and scoundrels can be told in megadungeon campaigns like Dead in Thay just as well as they can in globetrotting campaigns like Storm King’s Thunder. The stories are different, of course. They don’t really have an equivalent in fantasy literature. They’re more akin to Howard’s Conan stories or Verne’s Journey to the Center of the Earth than they are like Lord of the Rings, as megadungeon stories focus on very personal character motivations and tales of survival in a hostile and alien environment.
Megadungeon stories are often episodic, and tend to put more of the storytelling work on the player’s shoulders than plot-heavy campaigns. Let’s take Waterdeep: Dungeon of the Mad Mage as a timely example. Undermountain is as mega-dungeony as megadungeons can get, with no fewer than 23 distinct dungeon levels, each with a different environment, villains, and treasure. Each one of these different levels can feel like an episode of a TV show (even though each level will probably span 2 to 5 sessions of play, depending on your party’s preferred pace).
In an episodic TV show with an ensemble cast, like the new She-Ra or Star Trek, each episode is incited by a plot, but the real draw of these shows is to see how characters we’ve come to know and love overcome the challenge in their own way, while pursuing their own character-driven goals. This holds true whether they’re Adora, Glimmer, and Bow, or Kirk, Spock, and Bones. Megadungeon stories can be about uncovering ancient prophecies and saving the world from a mad mage, or they can be simple stories about treasure hunters getting in way over their heads.
One tiny cross-section of the massive Doomvault from Dead in Thay, a single story within Tales from the Yawning Portal.
NPCs and Roleplaying in a Megadungeon
My biggest concern about playing in my first megadungeon campaign was that I wouldn’t be able to meet fun NPCs along the way and roleplay with them. If we couldn’t visit any villages in a dungeon, then there wouldn’t be anyone to roleplay with. Once again, my fears were unfounded, though I have found that roleplaying encounters are less structured in a megadungeon than they are in other campaigns. Typically, I’ve been able to intuit which creatures I was “supposed” to parley with, and which ones were simply monsters to be killed.
Things aren’t so clear in a megadungeon. When you’re deep in the bowels of Undermountain, sometimes forming temporary alliances with hobgoblins or making a desperate bargain with drow raiding party is the only way to survive. Realizing this instantly flipped my false perception of megadungeons on its head. Hack ‘n slash isn’t the only way forward. Diplomacy and cunning isn’t just a method for dealing with the vast numbers of monsters in the dungeon—it might be the best way. Identifying warring factions in a dungeon and turning those forces against one another, like allying with goblins to overwhelm a rival adventuring party or a wererat gang in Level 2 – Arcane Chambers is a brutal, despicable, and absolutely brilliant way to solve an otherwise-insurmountable problem. Especially if you then stab the weakened goblins in the back and loot their belongings anyway.
And if the prospect of never returning to town worries you, let those worries be dispelled. Megadungeons thrive from having a nearby town, and all the best ones have a local village. After all, where are you going to sell all the treasure you’ve accumulated during your most recent delve? The Temple of Elemental Evil had the villages of Hommlet and Nulb. Undermountain has the Yawning Portal and Skullport (within Level 3 of the dungeon itself!).
These gith from Level 15 of Undermountain may not be your allies yet, but perhaps you could sway them...
Coming up for Air
Speaking of which, I’d like to dispel one final myth today. I always worried that playing a megadungeon meant spending the entire game within one dungeon. And while the dungeon will be your campaign’s primary setting, you won’t spend the whole game down there. Adventurers have to come up for air sometime. All that gold is going to weigh them down, and you have to sell treasure. Dungeon of the Mad Mage cleverly introduces side quests that begin and end in the Yawning Portal inn, encouraging adventurers to pace themselves and exit Undermountain every now and then.
This serves a couple of vital functions for both the players and the Dungeon Master. First, it lets the players return through areas they’ve already cleared and marvel at their own power and perseverance. They are mighty adventurers, and seeing the realms they’ve conquered in their quest is a great feeling. And, taken sparingly, stomping low-level monsters can be great fun. If your fighter had a nightmarish experience with a rust monster on the way down, letting her mow down a horde of them as she returns to the surface could be immensely satisfying.
Then, when the characters have sold their treasure, turned in and accepted a few quests, and spent the night partying at the inn, they can return to the dungeon with new purpose. Or… they can leave! Megadungeons don’t have to be all-or-nothing affairs. Maybe they found a magical spacecraft down in the dungeon, and now they have a new quest: find someone who can repair the craft so that they can explore the cosmos. Let Halaster rot in his dungeon, it’s not like he’s bothering anyone anyway. The party is rich, and they need someone who can repair a ship!
Let the party go off on their own and adventure elsewhere in the world for a spell. Then, when the need for gold and dungeon-crawling strikes them again, they’ll return to the endless pit of wealth and power that is Undermountain.
James Haeck is the lead writer for D&D Beyond, the co-author of Waterdeep: Dragon Heist and the Critical Role Tal'Dorei Campaign Setting, the DM of Worlds Apart, and a freelance writer for Wizards of the Coast, the D&D Adventurers League, and Kobold Press. He lives in Seattle, Washington with his partner Hannah and his corridor critters, Mei and Marzipan. You can usually find him wasting time on Twitter at @jamesjhaeck.