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How to stock dungeons

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

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 (challening 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. Again: all of this is when making the dungeon. Do not change it in play: if they are steamrolling, let them steamroll. If they are dying, let them.

Reusing other encounter tables

If you already have an encounter table, you can use it for stocking too (or just forgo stocking, as per “Key or table?” below.

Decide a level

But assuming you need to stock it yourself, 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”.

Imagine four player characters that have that same level. Three, in this case. That’s the “fictional party” you’re balancing against.

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. They might not be four (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 ixed 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).

Four is a magic number

I’m using four in this example but if your group is typically two people, or six, or seven, or five, or eight, use that number instead. Stick to the chosen number even for sessions where there are extra characters or missing characters: do not “adjust” based on players. When you are using a ready-made module and it says “there are two skeletons per character” or similar, instead use your chosen “ideal party size”, instead of counting actual heads at the table.

Dirty encounter math

The encounter math in the DMG is notoriously bad, Xanathar’s has another system, and Canathar’s also has the “quick matchups” that are even worse, but, that’s completely fine for our purposes. Our “paper before rock” was all the fairness we needed and any semblance of balance on top of that is just gravy.

You can use websites like or Kobold Fight Club if you’re doing something big and using computer tools but for a one-off, the Xanathar “quick matchups” is perfectly fine and I’m gonna show it here.

Only, we’re gonna make it even swingier! Swinginess and randomness is your friend here, it puts the outcome more in the hands of fate.

So the original Xanathar’s math have you facing four CR 2 monsters at level 5? We might instead place 2d4, or 1d6! We want random! We want random!

So at this point, I fill in my encounter table or map key with just the “no-appearing” dice, making any “dice swaps” as I feel like. I’m gonna use d6 here, but whenever you see 1d6, you can sub in 2d4 or 1d8, and when you see multiple d6 you can make similar swaps. (Maybe 2d6 is 2d8 or 1d6+1d8 or 1d12, whatever you feel like.)

I might have a list of four rooms, 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

Then once I’ve done entire list, I complete each line with a monster of the appriopriate CR for that number appearing.

This table is derived from XGE p91.

Dungeon Level 1d6 2d6 4d6
1 1/4 1/8 -
2 1/2 1/4 -

Note to self: complete this later. It’s basically just the Xanathar’s chart, p91

Each line says what’s an appropriate CR (or HD, although most good old school games have stocking rules already) for that many monsters. For example, say you’re making a level 4 area. If I have written 1d6 or 2d4, I use CR 1 monsters that are appropriate to the environment. If I’ve written 2d6 or similar, I use 1/2 monsters etc. All according to that Quick Matchups p91 table.

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!”

You don’t have to stick exactly to this, especially if you’re aiming the area at a tier instead of at a level.

But you should be aware of:

Three kinds of monsters

A trap monster is a monster that is summoned or unleashed or encountered if a trap goes wrong. It can be any CR.

A talkie is just a person, not a monster. Maybe this a prisoner they can free or another adventurer. These can also be any CR/level (use the ready made statblocks).

A par-for-the-course monster is where you really need to watch the CR. Party sees skellies? Party gonna bash. Again: be conservative and on the player’s side while prepping, but then run with gloves off.

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. Key up one third of rooms or less.

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.

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.