Since I've had a few people asking about megadungeon stuff recently, and I am an avowed megadungeon megafan, I thought it might be fun to walk through an actual example of megadungeon play that exemplifies what I like best about it.
This post is going to be the first in a series talking about a room from a megadungeon that I ran over 20 years ago (brushing past that fact quickly lest the horrors set in.) It was a major room, probably the most complex and important in the dungeon, and the players passed through it frequently throughout the campaign. In this post I'll introduce you to the room, and then in later posts I'll talk about what it does well and how to use that lesson more generally. Below the cut is a reproduction of the map as I remember it.
Recontextualization is a word I use pretty much every time I talk about megadungeons. Let's talk about what I mean.
The first time my players reached the concourse, the room represented a fight. Light matters a lot in dungeon crawling, and the concourse is illuminated by the skylight in the ceiling, so when the thief, scouting for the party, looked down the hall into the room, they could make out most of the layout without risking being seen. They did not like what they saw. Multiple tiers of balconies means multiple places for enemies to shoot from or throw stuff at you, and makes it that much harder to get at them. Meanwhile, the entryway is very exposed, and the enemy would be sure to see them coming. On top of that, there was the giant devil face and the column of light, neither of which posed any actual danger, but both are the sort of thing that sets off alarms in the minds of cautious adventurers, especially since the thief could see the imps very specifically avoiding the light.
As I mentioned in the first post, it took several more delves for them to decide to actually risk the room. Only once they felt they'd gotten everything they could out of the entry chambers were the party willing to brave an attack on the concourse. Justified caution. It was a difficult fight, with the imps on the balcony using their breath weapons to make the party's life miserable, and one of the PCs died. But, victorious, the room suddenly presented a lot of possibilities. Before taking the room, they'd essentially exhausted all the dungeon they had access to. Now they had access to three new wings of the dungeon, and the concourse represented the frontier.
So far, this is all standard dungeon stuff. Nothing mega about it. But the party had already done enough delves into the dungeon to face restocked rooms, and after how hard the fight to take the concourse had been, they were not looking forward to the possibility of new monsters moving in. Especially scary was the fact that there were doors to a higher floor in this room, which presented the danger of monsters from those levels coming in and taking the concourse. They checked all the doors they could access, and when they found that they could open G, they spiked it shut. (Incidentally, this was a smart choice. The first time I rolled to restock this room, they totally would have gotten monsters from the Halls of the Clergy if the door hadn't been spiked.)
For the next few expeditions, the concourse became base camp. Then, during one of their delves into the Pilgrim's City, they triggered a trap that caused a room to rotate, cutting off their path back and forcing them into an unknown section of the dungeon. For several terrified days, harried by spectral nobility, they skulked through dark and deadly halls looking for a way back to safety. And then, with several party members on the verge of death, they reached a barred door, opened it, and found themselves back in the concourse. Nobody has ever been so happy to see a giant stone devil's head before. Having finally unbarred door E from the far side, they immediately spiked it shut.
By this point, the party had needed to re-clear this room several times, and it had sucked each time. So, when they solidified an alliance with some dwarves living in the old dwarven section, they persuaded them to take control of the concourse. This finally made the room safe, and it effectively became the base of operations for the party for a while. It was the room they came back to to rest in, store stuff in, and they really felt rewarded for their alliance.
But they'd still never been to the fourth floor, and reader, some of those doors were not locked.
After more than a dozen sessions of having this room be their safety, the party managed to piss off the creatures in the Archives during one of their delves. Blissfully unaware that they had done that, they continued merrily on their way. Meanwhile, the Master Archivist, quite a powerful wizard, came out of door I and threw fireballs off the balcony until there was nothing left to fireball. By the time the party was done with their expedition, they came back to find their allies, their base camp, and their sense of safety nothing but a smouldering mess.
Without knowing what had done that (the popular theory was that something had finally triggered the devil head), the party spent a while not really trusting the concourse. It went back to a space that they moved through cautiously, a nexus of wings, but always with a constant looming danger.
But with the dungeon getting riled up, a local knightly order showed up to shut down all this dungeon delving nonsense and barred the party from entering, fully collapsing the tunnels previously used to enter. Denied access to the dungeon entryway, the party found another use for the concourse. They climbed up on the mountain, found the hole of the skylight, and Feather Falled down into the room. While the party would find a few other ways in and out of the dungeon, for a while their primary means of access was to Feather Fall in and Levitate out of this room. (After a troublesome fight Feather Falling into some oozes that had seeped into the room during restocking, the party wizard also started throwing a fireball down the hole first, just in case.)
Fully more than a year into this campaign, they'd get one last recontextualization of this room in the adventure. The Damned King, within his inner sanctum, had been a recurring antagonist as they progressed in their exploration. After finally confronting and defeating him, the party opened door H, and found themselves looking at the concourse from out of the devil's eyes. It chilled them to realize that all the time they'd spent in the concourse over such a long campaign, the King had been watching them from inside this room. It was also here that they found the lever to open door C and delve into the darkest part of the dungeon. With that, the concourse became the threshold of the final wing of the dungeon, and the gates of hell.
When I talk about recontextualization, I'm talking about a relationship to the space. Within this campaign, this room was a looming fight, a costly victory, a wild frontier, a foothold to be defended, salvation from disaster, home base, the site of a tragedy, shattered safety, a secret backdoor, treachery revealed, and the threshold of hell itself. That's an intense journey to take with a space, especially given that nothing in this room even does anything. There's no traps, no mechanisms aside from a simple door lever, no enchantments or magical effects. It's just a central space within the dungeon, and the player choices and megadungeon mechanics create the story. Important story arcs that formed the backbone of the narrative, like the dwarves falling to the Master Archivist, emerged entirely unplanned. If I were to run some version of this dungeon again, it would likely tell a completely different story, but I have every confidence it would be a compelling one.
As I noted in the first post, this room is one of the most complex in the dungeon. How do we keep the complexity manageable?
What makes the concourse manageable is that when the party first arrived there, it wasn't really particularly complex at all. It was a large room, for sure, but for the party, it was essentially just a room with three doors. The players had to care about doors B, D, and G. Everything else could be consigned to a problem for later.
The "problem for later" feature is an easily overlooked aspect of running a megadungeon compared to a standard dungeon, but it really does pay off. A party exploring a single-delve dungeon that comes across a challenge or feature will feel that they have to tackle it immediately. Either they are going to overcome the challenge now, or they're not going to overcome it. But in a megadungeon, unless something is in some obscure, difficult-to-reach corner of the dungeon*, the party can easily just come back. This makes it easier to put things like difficult puzzles into the dungeon, since the players don't feel forced to engage, but it also very neatly caps complexity. As long as the players have some path forward, anything that requires deeper engagement and which the players are finding too much to deal with in the moment can become a problem for later.
*You can also use this to your advantage. If you want to encourage your players to engage with something, for example something they'd ordinarily be cautious about, putting it somewhere hard to reach will encourage them to do so. I have seen many a player push an Inadvisable Button because they weren't trekking all the way back there later.
Choosing what to leave as problems for later also creates an opportunity for the players to express themselves. My party had just had a hard fight and lost a character, and were seeking safety. Not only were they not interested in pressing the riskier options, they actively eliminated them by spiking G shut. But another party might have immediately tried pushing their luck. Indeed, if they'd climbed straight to the 4th floor and gone through doors I or K (or, on an extremely lucky lockpicking roll, J), they would probably have been able to get their hands on some very powerful magic items and treasure without being forced into any unwinnable fights.
The second aspect that simplified the room was that the party could grow into it. They made it into the concourse at level 2/3 (depending on the class, in old D&D classes level up at different rates.) This meant their abilities were relatively limited. They were aware of all the other stuff they could potentially interact with, and they certainly could have tried some things, but they just didn't need to. They knew they'd have more options later, and so they waited.
As the party levelled up and continue to pass through the concourse, they started to consider the other options the room presented. The portcullis, F, could be lifted or broken down, or they could send someone through with a potion of gaseous form. The thief could, in theory, climb up to the 4th floor (in practice, the thief was extremely reticent to climb anything. In my experience, all AD&D thieves were either extremely risk averse or died quickly.) A Levitate spell could let them explore the upper floor and even out of the skylight.
Once they'd gotten so used to the room that the basic options no longer posed any cognitive load, they tried to lift the portcullis F and failed, before eventually using a potion of frost giant strength to get another crack at it and succeed. Eventually, they'd climb to the 4th floor and hang a rope down for easy access, pick the lock on door J, and start using the skylight as their primary dungeon access, but all these complications came on gradually, so they never felt like a lot to manage. The party simply developed a mastery over the space as time went on.
Some groups don't need that sort of complexity management. There are players who will absolutely juggle a room with 10 doors with no issues. But a lot of parties will fall into analysis paralysis with that many choices. Dungeon crawling does provide a natural pressure release for this. The party can always just open another door and see what happens. But in a megadungeon scenario, it's actually surprisingly easy to layer the complexity in such a way as it stays manageable, opening up gradually as the party grows into it.
I love being surprised as a GM. It tends to be what stimulates the most creativity, and generates the moments and stories I really remember. How does a megadungeon surprise me?
I've said before that the beating heart of the megadungeon is restocking and wandering monsters. These serve as ways to drive the evolution of the dungeon, changing spaces in ways that the players are not directly responsible for. They make the dungeon feel alive. And, importantly for me, they surprise me.
To start with, let's talk about the actual procedures I used.
For wandering monsters, there are a few different approaches recommended by different games, and they all tend to have different merits. I've used some really weird ones in some games to great effect. For this dungeon, I wasn't doing anything fancy. Once per hour, I rolled a d6, and on a 1 there was an encounter. If there was an encounter, I rolled on the encounter table for what it was. The table was a 2d10 table, so 19 different entries, with common encounters grouped toward the middle and more odd/extreme encounters toward the edges.
Notably, these encounters were not necessarily fights. All encounters allowed the characters a reaction roll, so conversation was frequently an option. I favoured an approach where lower numbers on the encounter table were more dangerous. So, rolling a 2 on the encounter table would mean finding something truly rare and deadly, while rolling a 20 would mean something very unusual, but much more likely to be helpful. (Other adventuring parties, for example.)
Procedures for restocking are notably harder to track down, and I could go off on a long tangent about it, but that's a different post. The procedure I actually used was to roll a d10 for each active wing of the dungeon for each day the party was away. On a 1, I restocked that section. I rolled a random number of rooms (1dSomething, with the die size based on the size of the wing) to restock, and then I rolled to determine where the new inhabitants were coming from. I would make a table based on the number of factions in play, meaning factions that were either in the wing being restocked or in an adjacent wing with access. A 1 on the die always meant roll twice, and it's conflict between the two rolled groups. Any unfilled slots meant something not aligned with any factions, possibly something new to the dungeon (so, for instance, if there were 4 factions in play, I'd roll a d6, with 1 being conflict and 6 being something unaligned. For 3 factions, a d4 with no "unaligned" option.) Once I'd determined how many rooms were being restocked and with what, I'd usually pick the rooms and the specific inhabitants myself. If I was stuck on ideas, or felt what I had so far wasn't interesting enough, I'd roll to determine which specific rooms were restocked.
So, in this room specifically, how did that play out?
As mentioned, the party had hit a few restocked rooms before clearing the concourse. These had been from the Redblades, a group of mercenaries who had been quartering in the entry chambers. Like a lot of out-of-work mercenaries, the Redblades had gotten into the banditry trade, and the party had first found the dungeon when hired to deal with them. This made answering the question of where the restocks were coming from fairly simple: responding to the party's first incursions, the Redblades called their roving bands in to fortify. In addition to refilling rooms with bandits, the restocked rooms added fortifications, with the Redblades digging in to defend their stronghold. After another incursion further thinned their numbers, I decided most of the remaining Redblades would abandon the group. Their leader, who the party was contracted to bring in, I had taken by monsters from the Pilgrim's City, leaving a trail to entice the players further in. My players were good sports, and would have kept dungeon delving regardless, but this made for a nice bait for them to head deeper.
After taking the concourse, the party hit their first wandering monster roll in this room while still patching themselves up from the initial fight. Given how injured they were, they were fully ready to try to negotiate their way out of a fight or flee. But the encounter roll was a Redblades patrol, and since the Redblades were no longer present, that meant no encounter. The party breathed a huge sigh of relief.
This is something I like to do with wandering monster tables. All relevant factions are on the table. This means that if the party is allied (or at least friendly) with some factions, sometimes a "wandering monster" is just bumping into some friends*. Factions that have been eliminated also stay on the wandering monster table for a little while. Eventually, the dungeon will adjust to their absence and those slots will refill with stuff in the dungeon. But for a little while, eliminating a threat doesn't just mean empty rooms, it means eliminating an active threat from the table. If there had still been Redblades in the dungeon, that patrol would have been coming from the entry chambers, cutting off the exit and leaving the party only the option to fight to the death or flee into unknown parts of the dungeon. But since they'd handled the faction, instead it was safe.
(*For sufficiently socially awkward people, bumping into acquaintances unexpectedly is also a wandering monster encounter IRL)
Once they'd cleared the concourse, it immediately became a tantalizing prize for every faction in the dungeon. When designing a megadungeon, I'll try to make sure every section has something valuable in it that factions not currently in that section will want. The concourse doesn't have much of value itself, but as the nexus of so many wings of the dungeon, it does control access. This meant that nearly any time I rolled restocking for the entry chambers, it started with taking control of the concourse.
This also meant that the concourse ended up telling the story of power struggles throughout the dungeon. The first time I restocked the concourse, I rolled conflict between the Archivist and the undead from the Pilgrim's City. This was surprising! These actually weren't factions I had considered to be in conflict with each other. (Usually, for any factions I can imagine the players parlaying with, I try to create at least some tension between them, but these undead were mainly mindless, so I hadn't done so.) Since the imps in the concourse had belonged to the Archivist, I decided that this meant that they had been there, in part, to contain the undead and avoid drawing attention to the dungeon. Now, unrestrained, the undead wanted to burst forth from the dungeon and feed. The Archivist was trying to keep them contained. When the party came back to the entry chambers, they found a few rooms where conjured elementals had culled skeletons and zombies that were headed for the exit, and the concourse itself was full of the walking dead.
Later, a number of the party contracted diseases during an encounter with an Otyugh, and were away from the dungeon for longer than usual to recover. This meant a lot more repopulation rolls. The first time in this period that the dice said to repopulate the entry halls, the faction moving in was the Wailing Countess from the Nobles' Section (the players had spiked E shut, but, y'know... ghosts can just walk though the closed door.) So, the concourse got haunted. But this meant that the ghosts were now in play for every wing that connected to the concourse.
And the dice loved them. Ghosts spread all over the dungeon, possessing dwarves, haunting libraries, defiling altars. This was, again, surprising. The Countess was supposed to be a minor player in one wing, but the dice had other ideas. I decided that the obvious answer was that she was looking for something. I ended up rolling to restock the concourse twice more before the players returned. The first roll came up with something unaligned. I chose to use another adventuring party the players had encountered on a wandering monster roll, and had them clear out the concourse from the ghosts. The second roll was devils from the Indulgences. As a result, when the players came back, they returned to a dungeon with ghosts lingering in many previously empty corners. They found the last remnant of the adventurers they'd met before bleeding out in one of the entry chambers, living just long enough to deliver a grim warning: the ghosts had been bringing an artifact to the Countess, the other adventurers had been trying to stop them when a great devil had fallen upon them. Now it was up to the players to retrieve the artifact and stop whatever the Countess' scheme was.
This was quite dramatic and did a great job of kicking off the next big arc of their dungeon exploration. My players assumed that I had plotted all this, that it was scripted. But the truth is, it was just me trying to make sense of the dice rolls. A different party, or a different set of dice rolls, and things would have been completely different. If they hadn't rolled the other party on the wandering monster table, and thus they hadn't been hanging out in my mind waiting for another use, things would have been completely different. And that's what these procedures do for me. They let the dungeon develop in unexpected ways, to tell unique stories. They surprise me.
