### Original Monster Level Matrix

Observation 1: According to this table, on the 1st dungeon level, any of monster levels 1-4 can appear regularly. Based on our initial Equivalent Hit Dice (EHD) analysis (link), the average monster on this level is not 1 EHD in power; it’s actually a little over 3 EHD that our 1st-level PCs can expect for a “standard” encounter there. Any one such encounter is a deadly threat, even solo against 4 PCs, say.

Observation 2: By the 3rd level of the dungeon, monsters across the entire spectrum can be expected regularly. For example, within a half-dozen encounters, our presumably 3rd-level PCs can expect to confront one 6th-level monster, such as: an adult dragon, 10-headed hydra, vampire, balrog, or purple worm (various EHDs between 12 and 39 for these types). And there’s simply no way that a 3rd-level party can hope to regularly run into encounters with even a solo creatures of EHD in the 20’s or 30’s and expect anything other than a TPK.

You get the basic idea regarding that original Monster Level Matrix. Just to nail the issue home, here’s the demographics resulting from stocking dungeons blindly via that table. Using a data file that matches the original Monster Level Matrix, this is produced with the current Arena program using the switches

**-n=10000 -v -z=4 -rs**(that is: a population of 10,000 men, versus monsters, in parties of 4 at a time, reporting summary statistics; with default dungeon treasure, 24 fights/year, and 50 years total time):

Note that even after the 12 million separate combats that this represents (the 10K population is constantly refreshed as adventuring men get killed off), it's almost impossible for anyone to have graduated past 6th level. Perhaps more troubling is the fact that their isn't any evidence of higher average ability scores (esp., Str, Dex, Con) at the higher levels; this is a signal that character ability is effectively a non-issue, and affords no benefit in survivability. Basically everyone is just being thrown into a big random meat-grinder.

### Revised Monster Level Matrix

So what do we recommend for a replacement to that table today? Here’s a simple solution concept: Let’s say that an Nth-level party, operating on the Nth-level of the dungeon, should expect to run into monsters of Nth-EHD, on average. (Obviously, that is far from what the original matrix produces). To the extent that the Monster Level Tables partition various EHDs into coarser chunks (see last post), we’ll simply reflect the same in our new matrix: six monster level tables are synchronized with six rows in the new matrix. Each row of the matrix covers the same dungeon levels that the equivalent monster table covers in terms of EHD. In each case, the average die-roll of “3-4” should sit where the row matches the column number (i.e., where party level matches monster EHD; symmetric down the diagonal). The result is the following (as in the data file on GitHub):

If we run our Arena simulation using this new matrix (same parameters as above), then we get the following demographics for the adventurers in question:

Now, that's still a hard game; while there are more 7th- and 8th-level characters present, still no one succeeded at cracking Name level (after 50 years of adventures by the 10K population). No one can accuse us of giving away the store with this modification; arguably we could dial down the generating matrix even more than this. Note, however, that character abilities do now seem to correlate with survival, especially in the average Dexterity column here (for man-vs-man fights, we've previously seen that Strength is more fundamental). So this might represent a simple and reasonable upper bound for Monster Level Matrix difficulty. Also, if the DM regularly places "special" treasure at a steep multiplier over table-generated treasure (as sayeth the book), then advancement would be more swift than this; at least the PCs would have some chance of surviving to benefit from such treasure caches.

Still to come: Monster numbers and treasure value.