Underworld Overhaul, Pt. 5: Dungeon vs. Monster Treasure

Throughout our investigation of the OD&D underworld stocking system, we've taken for granted that the treasure table in Vol-3, p. 7, with the first column titled "Level Beneath Surface" -- what I call the "dungeon treasure" table -- is indeed the standard in use for treasures in the dungeon. We have many points of evidence that the Vol-2, p. 22, "Treasure Types" table is for use only in wilderness adventures. However, here we entertain the thought: what if we used monster-keyed treasure types in the dungeon anyway?

There is an undeniable attraction to that idea. In particular, the treasure types system seems to give a certain "flavor" or preference to the treasures commonly found with different types of monsters. For example: Men (Type A) have large amounts of treasure and prisoners. Dwarves (Type G) have large amounts of gold, and reject any baser metals. Dragons (Type H) have overwhelmingly huge piles of treasure. Rocs (Type I) may have gems but can't collect coins. (Note the extreme specificity of those latter types; the monsters I just named are the only ones keyed to those treasure types.) On the other hand, a great many monsters are entirely lacking any keyed treasure type; e.g., skeletons/zombies, most fliers, extradimensional creatures, oozes, insects, and animals.

Expected Values

As a lead-in, it may be helpful to inspect the expected values of each of the different treasures possible. In each case this is done via the Arena code package, with the unit tests built into the appropriate code modules, which perform simple Monte Carlo simulation methods. Expected value for dungeon treasures, by level (rounded to two figures of precision):

And here the same for monster treasure types:

Note, however, that all rolled values are highly variable; in particular, the vast majority of expected value comes from the rare and high-value gems and jewelry (esp. the latter) in each case. For example: At the 1st dungeon level, 95% of treasures lack any jewelry, and such treasures have an expected value of only 90 gp. On the other hand, the 5% of 1st-level treasures that do include jewelry have a class expected value of 12,000 gp. In this perspective, we might say that the core D&D game is one of PC adventurers searching strictly for jewelry -- after about 10 treasures (at 1st level) they have a 50% chance of having secured jewelry and so leveling up; whereas any other treasure is effectively negligible. (Later levels have somewhat less variance than this, as the chance of gems/jewelry rises; but note that chance maxes out at 50%.)

We might compare the average treasure-type values seen here to the similar chart presented in Moldvay's Basic rules, p. B45 (repeated in Cook Expert, p. X43). He has overall lower expectations (about half what we see here), and yet the main treasure type table looks to have copied all the entries from OD&D, even adding new columns for electrum and platinum. This would seem to imply equal or higher value, so how can that be? Again, this is explained by the majority of value residing in the gems/jewelry. Moldvay has modified the gems table -- emphasizing chances for the lower-valued types; and even more radically restricted the jewelry -- allowing only the lowest-value category from OD&D. And hence overall lower expected values for the same treasure types.

Adventuring Demographics

Using the current Arena program, it's simple to explore using the two different treasure tables; by default the dungeon treasure system is used, while the -t switch forces use of the monster treasure types instead.

Note the following: When dungeon treasure is used, it is generated for every encounter (waived the 50% for treasure, but also not including any DM-placed high-value "important treasures"). Likewise, if monster treasure types are switched on, then we consult the type table for every encounter (waiving the "% In Lair" chance designed for wilderness adventuring). On the other hand, we honor the Monster Manual rule that monster treasure types be scaled in proportion to the average monster number appearing in the wilderness; whereas there is no such suggestion for dungeon treasures, whose distribution is thereby fixed (regardless of monster numbers). Note that since we scale monster numbers by party size, the average shares of monster treasure stay fixed for larger parties, but shares of dungeon treasure decrease for larger parties.

The following repeats (from the last few posts) the demographics from parties of size 4 adventuring in our dungeon, with monster numbers fixed in proportion to party size (no variation), using the default dungeon-treasure setting (Arena switches -n=10000 -v -z=4 -rs):

And here are the demographic results if we instead use the monster treasure types (adding the -t switch):

Conclusions: First of all, the monster treasure types generate significantly less treasure than the dungeon treasure system. This is reflected in the fact that dungeon treasure supplies about two-thirds of XP when in use; but monster treasure supplies slightly less than half. That might come as a bit of a surprise -- I think there are some misconceptions, based on impressions of the very large Dragon treasure (for example), forgetting that the vast majority of monsters in the system have little or no treasure whatsoever.

Secondly, and as a result of that, the use of the monster-treasure system would make it harder to advance in levels past the 1st. Comparing the two charts above, the monster-treasure population has roughly half the numbers at levels 3-5 (as compared to the top dungeon-treasure chart); and only about one-fifth the numbers at levels 6-7 (and in fact, the solitary 7th level character may be something of an outlier, with their excellent Dexterity and Constitution scores).

In summary: While there is some charm in the flavor of bending the rules to use monster treasure types for dungeon adventures, this results in overall less treasure, and makes things even harder on the PCs in terms of advancement opportunities (and is also more calculator-intensive, in that it requires scaling down from the table in proportion to number of monsters encountered). We would recommend sticking with the OD&D Vol-3 dungeon-treasure tables for underworld adventures.

Important Treasures

A final consideration; granted that we plan to follow the dungeon-treasure placement rules in Vol-3, it is important to recall (again) that the foundation for that system starts with the DM placing "important treasures" by fiat, prior to any random methods being used (p. 6):
It is a good idea to thoughtfully place several of the most important treasures, with or without monsterous guardians, and then switch to a random determination for the balance of the level. Naturally, the more important treasures will consist of various magical items and large amounts of wealth in the form of gems and jewelry.
So: How big should these important treasures be? (We ask, of course, because this can have a larger impact on PC survival and advancement than anything else we've analyzed in the system to date.) If we take literally the recommendation that they include "large amounts of wealth in the form of gems and jewelry", then we note the following. A dungeon-treasure including gems has an expected value of double the basic treasure; and a treasure including jewelry has an expected value of twenty times the base. So it would be legitimate to glance at the dungeon-treasure expected values above, and place special treasures (including gems/jewelry) at something like a 10-fold or 20-fold multiplier (or more) on each level. Be sure to stoutly guard such treasures with copious monsters and fiendish traps, of course!


  1. OK, so lets see if I get this.
    I am designing the Tomb of Utter Destruction and its 14 levels of evil.
    For each level, I am thoughtfully placing a massive/important treasure. ~10,000gp worth on level 1, ~22,000gp on level two and so forth.
    Incidentally, being "important" treasures, I assume these are what the local tavern rumors talk about.
    Then as the party wanders to find the tomb, I am doing random encounters, and rolling treasure by Type (and there is percent chance that the creature/treasure is in a lair?)
    They get to the tomb and must fight devilish traps and monsters, with additional per monster treasure using the dungeon depth table.
    I guess the fact that there is extra/bonus treasure helps explain why traps don't come with their own XP awards in older systems.
    I wonder if your simulator could run the numbers on a whole campaign, complete with wilderness/wandering to and from the dungeon/wilderness encounters/treasure and the depths/dungeon encounters/treasure.

    1. That's a good slice of it. My main thesis is to not use the Types in the dungeon. I would assume that wandering monsters don't have treasure. And the whole issue about being in-lair is so undefined there that I also want to avoid that.

    2. Is there a time to use treasure type?

    3. Baquies - at normal scale, they work pretty well for large, dangerous lairs in the wilderness, intended as targets for mid-high level adventuring parties well-equipped with magic and hirelings.

    4. That's it. Like it says on the tin (OD&D Vol-2 p. 4; AD&D MM p. 5).

  2. I've found a slightly different way to use the treasure tables from the manner in which they were intended, at least as far as site based ("dungeon") adventures.

    When designing an adventure, I first consider the party size and average amount of XP needed to gain a single level; this is the total GP amount of "treasure" I include in my design.

    I then determine how many encounter areas will have treasure based on Moldvay's suggested rations (one-half of monster encounters, one-third of trap encounters, one-sixth of "empty" (non-trap, non-monster areas).

    Treasure VALUE I divide by the the "50% rule:" half the total value is in a single area, half of the remaining is in a second area, half of this remainder is in a third, etc. For example, if the total treasure amount was 50,000 for 10 areas it would look something like: 25K, 12500, 6250, 3125, 1563, 782, 391, 195, 97, 97. These are rough figures.

    I then use the average value based on treasure type to determine which creatures get specific values: a pair of ogres (type C + 1000) might get the 1500 treasure value, for example, while a cyclops (type E + 5000) or trap with commensurate damage output guards the 6250. Sometimes, the largest treasure might be in an "empty" room, protected by a secret door with an especially fierce monster or guardian providing easy access by dint of being located outside the door.

    I admit, it's not an exact science, but it works for me as rough guidelines. It's highly unusual (in my games) for a party to "pick clean" an entire adventure site, but I like to have it stocked with the POTENTIAL for advancement.

    [the exact makeup of a treasure...coins, gems, etc...I determine myself based on what seems sensible for an encounter area; the "average value" by treasure type is my guiding measure]

    1. I think that's really great, and I wish that the original books had a quantified recommendation/system along those lines.

      I am fond of using the 1-2-5 series as a simpler approximation to a doubling sequence. Wikipedia.

      The way I personally set up my last dungeon was like this: One treasure worth 5,000. Two treasures each worth 2,000. Four treasures each worth 1,000. Various other loose-change stuff. That seemed to be pretty satisfying for my taste.

    2. The distribution system found in B/X is based on the one found in Book 3 of OE (page 6-8), though that system ignores traps (2 in 6 chance of a monster, 4 in 6 chance of "empty," with treasure distribution the same as B/X: 50% and 16.6% respectively).

      1-2-5s not bad (and far be it from me to dispute with a math professor), but it would seem to make for a far "richer environment" with all that loose change lying around. Maybe I'm reading it wrong. My system works out to (almost) a 1-in-3 chance of finding treasure (11 treasures in a 36 encounter site). Many of these will be concealed, squirreled away, or incorporated into the "danger" of the encounter (a golem with gem stone eyes, a treasure that possesses a curse, etc.)...want to maintain the impression these things were "missed" by previous explorers. In general, what's your ratio of treasure-to-encounter?

    3. I agree that 1-in-3 feels really nice; that's exactly what I aimed for in my recent designs. See also here for an analysis of Gygax's published dungeons (which broadly saw the same 1-in-3 treasure frequency).

  3. On the subject of loot. .. Do you give npc character types (swordsmen, etc,) magic items at the 1 in 6 per level chance? When doing so I found this was the main (and basically only) way to run across magic in the dungeon.

    1. Yes, and you're right that it turns into a primary source of magic items (assuming you place numerous NPCs). There's an argument to be made about that, but I do think they're underpowered without it. (Plus I like just having one consistent rule to recall for Pcs & NPCs.)

  4. What are you using for XP for monsters these days? Is it something based on EHD? What would you expect the ratio of monster-to-treasure XP rewards to be on average?

    Also, did you (or blogspot) change the options for commenting login? I used to be able to use OpenID from my blog, now it seems to insist on a Google login.