Statistically Average Shadowdark Dungeons

16 Sep, 2026

Ok, buckle up kids, this is gonna be a long one and there's gonna be math.

I was inspired the other day while re-listening to Blogs on Tape read an article which I have read many times before, Traverse Fantasy's Bite Sized Dungeons. In it, Marcia B discusses interesting way sto organize rooms in a dungeon to create looping paths and interesting exploration possibilities. But she also talks about the statistical distribution of rooms in a B/X style dungeon creation. Specifically, she references THIS post by Yora of Spriggan's Den which discusses the idea of an 18 room dungeon as a great baseline for the statistically average B/X dungeon experience. And looking over the ratios presented in the B/X dungeon stocking tables got me thinking about the corresponding tables in the Shadowdark RPG core rulebook.

B/X vs Shadowdark

Per Yora's blog post, the B/X dungeon stocking tables breakdown thus:

Presented as percentages, that looks like this:

Adding up the various percentages, that all maths out to an approximately 27.79% chance of any given room having Treasure (and therefore XP).

By comparison, the percentages for shadowdark break out thus:

Adding up the various percentages (not that you actually need me to do it), we get a 10% likelihood of any given room having treasure (and therefore XP).

Addendum (9.19.26)

Something that was pointed out on reddit (I'm going to have more to say about reddit in an upcoming post, but suffice to say that I'm taking a break from the social internet for a while) that I had overlooked is Page 113 of the Shadowdark Core Book, which says that 50% of encountered monsters should have treasure. Adding that into the schema above, we have 4 monster entries (40%) that each have a 50% chance of having treasure, or a 20% overall chance of any given monster room having treasure. Adding that into the original 10% chance of treasure, we get a total percent possibility of 30% of any given room having treasure.

That increase in no way changes the analysis below, as it was focused on seeing what the Arcane Library dungeons work out to in treasure prevalence, but having looked at that it would be interesting to go back and see which treasures in the "official" dungeons are tied to monsters and which are independent treasure finds. That wasn't something I looked at in this particular analysis, but I might someday go back and check that out.

End Addendum

Seeing that breakdown got me curious to see if Shadowdark dungeons actually follow that probability, or if there's a secret hidden number that I need to start caring about.

Methodology

To see what (if anything) I could learn about this, I went through every currently available Arcane Library Shadowdark dungeon. This includes all of the Cursed Scrolls (minus Cursed Scroll 3, which I'll explain a little further down) and all of the mini adventures, including all of the preview versions released as part of the Western Reaches kickstarter. I was left with a total of 25 dungeons to evaluate.

I defined a "Treasure Find" as any room containing items which could be classified as treasure, including non-shiny items, weapons, and adventuring gear.

I used the table on Page 117 of the Shadowdark Core Book to define the XP value of a treasure find. In general, I assumed that an individual find (unless it was particularly impressive) was 1XP and a "hoard" of treasure comprised of multiple individual treasures was 3XP.

Raw Data

(Formatting that in markdown was SUCH A PAIN)

Cursed Scroll 3: Midnight Sun was excluded from the data because it is a Level 0 Funnel, and therefore any XP gained via treasure finds in the dungeon are moot -- the characters reach First Level upon surviving the adventure, and so there's really no point in actually awarding XP for treasure finds DURING the adventure.

Analysis

(can you tell that I read and deal with research papers on the regular?)

Right, so, looking JUST at the totality of the data, we get this as our average results:

HOWEVER, in the interest of not being led astray by outlying data (I'm looking at YOU, Cursed Scroll 4), we have the following additional averages calculated:

Small Adventures (13 rooms or smaller)

(note that these averages do not include the CS4 adventure Black Seed, which is an outlier at 3 rooms and 13XP)

Large Adventures (Larger than 13 Rooms)

Not Counting Cursed Scroll 4

Discussion

Ok, so now that we have our numbers, we can start talking about them.

First of all, WAY more than 10% of rooms have treasure in "Official" Shadowdark dungeons. Across the board, it's between 40-50% of rooms that have treasure (more than B/X either, but that's a LOT closer).

The average Treasure Find is at least 1XP (that should probably be obvious, but hey, there IS such a thing as a 0XP find), and sits comfortably between 1 and 2XP. Using the schema from the Shadowdark rules, this means that the average dungeon should include at least 1 Treasure Hoard worth 3XP, but there should be more than double the number of 1XP find as there are 3XP finds (to maintain the average of below 2).

Related, but not necessarily represented in this data is the rule on Page 117 of the Shadowdark Core Rules that any given treasure find should be worth approximately 10 times the party's average level in GP. This is a good benchmark to keep in mind for the players having cash to spend on carousing when they get back to town, but also doesn't account for any magic items that might be found. It really falls down to the valuation of hard cash and valuable objects in a find.

Conclusion

Long story very, very short is that the stocking procedures in the Shadowdark Core Rulebook don't match up mathematically with the example dungeons from The Arcane Library. I'd go so far as to say that the ACTUAL way that treasure finds are calculated is "well, it makes sense for there to be some loot here, here, and here," rather than holding to any particular mathematical average.

That said, the math supports that about half (or slightly less, around 40%) of the rooms in any given dungeon should have SOME KIND of treasure find, whatever that value ends up being. The majority of those finds should be of the 1XP variety, with sprinkled in 3XP and 0XP finds.

This number will, of course, get nudged in either direction depending on GM and designer preference, but I'd say it's a good benchmark to shoot for overall.

My Stocking Table

All of this kicked off because I wanted to find a good benchmark stocking table to use for MY writing. And through a few iterations and doing all this math, this is what I've ended up with:

This adds up to an overall 36.12% chance of treasure in any given room, with EVERY room type having at least some chance of there being treasure. I have also more explicitly included Traps as a type Hazard (I'll write about my thoughts on traps at some point, but definitely not today 'cause that's another long one).

To be completely fair, I haven't tested this table yet. I AM currently working on two new dungeons, so I'm going to be playing with this to see if it fits my design preferences, and I'll report back as I start finding things out.

Thanks for sticking with me through this one, I know that math is annoying and can definitely drive people crazy.