How to stock dungeons

Assuming you have a map and some treasure, here’s how you put monsters in.

If you already have an encounter table, you can use it for stocking too (or just forgo stocking, as per “Key or table?” below). Old school games like B/X come with an encounter table sorted by dungeon level already so you can just pre-roll an encounter as you make your key.

But if you don’t have a table, here’s how you make one.

Decide a “dungeon level”

The first thing I do is decide a level (or tier, if you wanna be a li’l bit more loosey-goosey) for the dungeon. For example, let’s say you’re making a “level three area”.

You then place this dungeon further away than (nominally) easier dungeons, and closer than harder dungeons. Not even this is a strict principle. Some outliers and blurred lines is completely fine, or even good.

Note that this is all you’re using the “level” for. At this point, you should have no idea of the sorry state the sadsacks that actually visit this place is gonna be in.

Let me say that again: you are not balancing the area against a specific party (see Paper vs Rock below for why). You are only balancing the area relative to other areas.

They might not be their usual amount of characters (maybe your out of state cousin dropped by unexpectedly, or maybe some of the characters died or someone is missing a session) and they might have mixed levels. They might be precocious underleveled chars or they might be cowardly high-level chars grinding away for easy loot. That’s good! That’s the point of this philosophy: you’re never “serving up” an encounter, it’s them that go on adventures and make choices and get into trouble (or not). Player agency!

Make a list

This step is the same whether you’re making an encounter table or a room key.

Wherever you want to place monsters, don’t decide what kind yet, but note down how many monsters are there, perhaps in the form of a dice expression if there’s more than one. Maybe you want a room to be crawling with monsters so you put in 3d6. Or you feel like there’s only one monster in there, so you put 1. Or you have some other specific number in mind based on the diegetic circumstances of this location. Leave room on the line to write what kind of monster it is.

I suggest using 1, 2d3, 4d3, and 8d3, if you’re in doubt, for “one”, “a few”, “a handful”, and “lots” respectively.

I might have a list of four encounters, and be like “do I want many easy monsters here or just a few hard ones?”, I might go:

1. 2d4
2. 1
3. 2d6
4. 1d6

(If my list includes every room, not just the rooms with monsters, then I’ll only put monsters in about a third of the rooms.)

Select monsters

Then I complete each line with a monster of the appropriate CR for that number appearing.

Now, old-school afficionados are cursing and balking; “whaddaya mean CR? Balance is a false god!” and that’s the correct attitude when running dungeons, but not when making them.

If the monster is a “trap monster”, i.e. it will only be summoned if something else has gone really wrong, then it can be any CR. If the monster isn’t a monster at all but a person that the players are more likely to talk to (or rob or rescue or steal from or whatever), then it can also be any CR. That’s something 5e got right: ready made statblocks for “nobles”, “guards”, “scouts” etc you can just grab.

But if the monster is a monster the players might attempt to hack & slash at, that’s where CR comes in.

Cross reference this table of dungeon levels with dice expressions to find out a CR ceiling for the monster type. For example, you’re making a Dungeon Level One area and you’re selecting a monster type for an encounter with 2d3 monsters. You look in the Dungeon Level 1 row and the column that has 2d3. That means CR ¼, so skeletons for example. The CR is a ceiling; feel free to go lower.

This part is actually really fun. This is such a mind hack for me. I have such a hangup against just writing “hohoho, there’s gonna be 4d6 stirges down here”. I feel like it’s me killing the characters and I just don’t want that.

But splitting it up like this instead tricks my brain into two fun and easy steps. Step one: “Probably guards posted here, 2d4 is good for guards” or “This is a huge chasm, put 4d6 weenies down here.” Step two: “What’s a good CR 1 underdark monster that they can meet 2–8 of? Oh, I know! This one!”

I’m trying to base this off of this math.

Mixing and matching

It’s fine if there are more than one monster type; remember that the CR in this table is just a ceiling. So if you have 4d3 creatures on dungeon level 8, indicating CR 2, it’s fine if you make that 3d3 CR 1 creatures and 1d3 CR 2 creatures, for example.

Or you can figure out other ways to mix and match if you really want a set piece, using the Hughes-derived formula (sum of CR should not exceed dungeon level, or twice dungeon level once you’re out of first tier, and no single creature’s CR should be more than 1.5 times the dungeon level). But remember; when you are overdesigning encounters you run the risk of getting tempted, subconsciously, to steer play in that direction. If you instead stick to being lazy & sloppy you are more likely to let the players drive the direction of play and that’s often better.

Key or table?

You need an encounter table. It makes the dungeon come alive.

If you have an encounter table, you do not need keyed areas (instead, you can have an extra chance of an encounter (as opposed to an extra guaranteed encounter) whenever they enter a new room, on top of when time increments).

But when I can, I like having both.

It’s fine to just have one or two keyed encounter and the rest be random. Of course, treasure and traps and other features should be keyed. We need some texture in here. Creatures on the other hand, it makes sense that they roam.

Moldvay suggested a monster in a third of the rooms (and those rooms have 50% chance of treasure also), a trap in a sixth of the rooms (with a ⅓ chance of treasure), a third of the rooms completely empty (with a ⅙ chance of treasure), and a sixth of the rooms have something special, and he also suggested a ⅙ chance of something from the encounter table every other turns (every 20 diegetic minutes). In my experience, those Moldvay suggestions work great.

Why I needed this

This page is the one thing I wish I knew when I first started out.

To me the “adventure” type roleplaying games seemed like a maddening paradox. The games I was reading had utterly cumbersome character creation with point juggling and long lists to parse through, while on the GM side it was just like

Book: “lol make up some stuff”
Me: “How do we balance it, how do we make it fair, what if they die?”
Book: “lol just cheat so they don’t die”
Me: “But they why should we bother making characters for forty thousand hours if it’s all shadowplay on the other end? Why should I even bother with you, book?”
Book: “whoopsie!”

So I struggled and searched and failed to find something like this page you’re on right now. (While I was looking, I’d just play rules light games. They solve the paradox in another way, by removing rules on the player side to match the GM lightness.) After a while, I’d find games like Rune or D&D 4E that tried to “balance” encounters and areas with the party’s current level. “Gamism.” That’s a heck of a lot better than nothing, but then I found my dream setup: the blorby way of playing, where the entire game world is the challenge. They can steamroll some areas and have to flee from others, and they might even die, but that’s part of it; it’s not level scaled to them, it’s not quantum or adjusted, it’s real.

No Paper after Seeing Rock

Quoting from my own blorb principles:

When you play Paper Scissor Stone it’s obviously cheating to act a little bit slowly and select paper after seeing rock. Both people need to select simultaneously.

If you secretly write down your selection in advance, you don’t have to be as precise with the timing. Your selection is committed long before you saw that rock.

Even to the point that it’s enough for one person to write down their selection, as long as they write it down before the other person announces their selection.

Blorb is based on this. That’s why you need to write “this room has 3d6 skeletons” before the players go there. No quantum keeps. You’ve got to let them make real choices.

That is a restriction. But it’s also a tool. Following that principle, you can put anything in a dungeon and it’s fine as long as you committed to it before play started, and you’re sticking to it. You have “the prepper mindset” while making the location (challenging but winnable) but “the runner mindset” when running it (brutal and unflinching).

Since this is “paper before rock”, no further balance is necessary, the rest of this article is optional. It’s not law, it’s just good practice. After all, you’re in the “prepper mindset” now and you might want some guidelines. When you’re prepping, you’re trying to make it hard but avoid a TPK. The prepper’s goal here is to make something not too easy, not to hard. The guidelines on this page is here to help with that.

Again: all of this is when making the dungeon. Once you’re running the dungeon, it’s like you’ve taken a swig of Jekyll-and-Hyde juice because now you have to completely ignore that “balance” and instead run it as it is. Do not change anything in play: if they are steamrolling, let them steamroll. If they are dying, let them.

This also means that the more “distance” you can put between you making the dungeon and the player characters visiting the dungeon, the better. That’s why I love running modules, that’s like the maximal “distance”. When I make homebrew I want to put in more randomness, and be heavy on chances of something not happening, so that not everything I cook up is going to happen for sure.

If you need a dungeon now now now for a given party, and you know the party composition (and they don’t have a chance to change that party composition by leveling elsewhere or hiring henches or gearing up or fidning out rumors or scouting ahead), you’re kind of in trouble. In that case, I’d want to leave things as much to the gloracle as possible by sticking to the 1, 2d3, 4d3, 8d3 amounts and Moldvay’s room stocking procedure.

If you’re making dungeons way ahead of time, that’s when you have a lot more freedom. I like having a lot of level one dungeons (and then those dungeons can have level two areas beneath them and so on). A huge problem with WotC’s adventure collections is that they have one adventure per level. That is not the sandbox way. That setup assumes things going a particular way, and that’s not usually how things happens. Instead, they might die at level 4, or level up faster or slower than you had expected.