One of the things I really like, DM'ing games from the Original D&D LBBs, is that all hit dice and damage are d6-based. So I can set up with a big batch of d6's (wargame-style) and use that for all monster hits and damage without poking around for sufficient d8's for hit dice, or 5d4 damage or something. In addition, it's very rare for monsters to be noted with multiple attacks, so combat goes quite rapidly.This got massively reworked in Supplement-I (), and personally I think it's one of the off-the-rails mistakes in the history of D&D. In this work, you get the establishment of different hit dice by character class, variation of damage by weapon type, and also variation in attacks and damage by monsters (each listed as "Addition/Amendment" and "highly recommended"). Actually, the first two -- giving increased granularity on the player side -- I have no problem with, but simultaneously complicating all the monsters is the part I prefer not to use.As that was done, the damage output from monsters increased, approximately on the order of being doubled. Let's take a closer look: Below I've compared all the monsters in OD&D Vol-2 that are given explicit damage specifiers in their text blocks, with the "new" damage specifiers given in Sup-I. Note that by default all the other monsters should have 1d6 damage in Vol-2, but for brevity I haven't listed those (and also confidence: did Gygax really make a deliberate choice that dragon bites, purple worms, etc, should do 1d6?).You can see above that a comparison of the average damage output for these types shows a linear relation from Vol-2 to Sup-I, being a bit less than doubling between those works. We should be a bit careful, because the correlation isn't perfect; for example, ogres have the same average damage in both volumes. There are also a number of monsters not shown here who effectively havedamage, by being given less than 1d6 damage in Sup-I (kobolds, goblins, giant rats, etc.)One thing that complicates my desire to stick with the LBB all-d6 (low damage) method is that while in Sup-I the amendments were quasi-optional, everything that came later on was designed only in those inflated, non-d6 terms. For example, there's a lot of interesting and memorable D&D monsters that only appear in later supplements: like lizard men, harpies, liches, ogre magi, hell hounds, owl bears, golems, giant frogs/toads/beetles, sahuagin, demons, and many more. Stat blocks for these types are only available with the inflated numbers.(Note there is one unique exception here: In Sup-I, the text entry for the new Storm Giant type is the last place to give LBB-scale damage, "unless the alternate damage system is used". So the text says 3d6+3 damage, while the revised table in the same book gives 7d8 damage; a big difference.)As a possible solution, consider taking the regression formula above and reverse-engineering all the supplement damage scores, so we get something back in scale of the LBBs. For simplicity, I'm only listing the maximum-damage dealing attack for any monster given multiple attacks in Sup-I. I've also made an executive decision that anything up to 1d6 in Sup-I is unchanged (so the kobold/goblin/rat 1d3 or whatever isn't further reduced, and neither is an orc's 1d6, etc.), but everything else is inverted by the formula. Having back-adjusted the average value, I use another spreadsheet function to suggested the best possible all-d6 damage dice. Here's a snippet from the first few results:The fifth column over has our formulaic suggestion for damage dice in LBB-scale. The sixth and seventh columns are my manual choices for what I'll use in my own OED house rule games. Orange boxes are entries explicitly noted in LBB Vol-2 text, and I'll leave those fixed in each case (note they're generally quite close to our calculated suggestions, e.g., for giants).That entire spreadsheet is available here, including suggested conversions of everything in the Sup-I and Sup-II tables. Note that the Sup-I damage table has three distinct parts: (1) revisions for monsters in Vol-2, (2) some damage specs for giant animal types possibly in LBB encounter charts but otherwise without stats, and (3) new monsters appearing in Sup-I itself; these are set off in white, yellow, and green sections of the spreadsheet. Meanwhile, looking at the Sup-II table, it's possible that Arneson was even more unhinged on the issue, e.g. damage of up to 24 points for a sub-1 HD fire beetle, 80 points for a plesiosaur bite, or 150 points for a whale fluke! (A lot of those figures were later reined in by Gygax in the AD&D.)Finally, I've done a recent revision to the OED Monster Database which (a) edited some damage figures to be consistent with this analysis, (b) added a number of giant and aquatic creatures from Sup-II, and (c) expanded the sourcing/reference information in the last column. All of the damage values can now be rolled on d6 (previously I kept some d8 values in there, as per the supplements). There are currently a number of damage values like 1d6+1 or 1d6+2 (as the LBB Ogre), which shades towards fiddly for me, but I think I'm okay with it for now. Some of the EHD values moved up or down by one or two pips in some cases, as well. We now have 174 monsters in the database. :-)