OSR: HD(NA) of the Monster Manual + MMII + Fiend Folio

I'm working on a new project: the Monster Overhaul. This post is part of the planning process.

In Volume 1 of Original D&D, Gary wrote that “There is no reason that players cannot be allowed to play as virtually anything, provided they begin relatively weak and work up to the top.” I’ve noted that I played several Balrogs, and way back in the Introduction, I told the story of Sir Fang, the first Vampire player character.

Note, however, that Sir Fang was not the LAST Vampire player character.

One of the gang at the U of Minnesota wanted to play a vampire. This was LONG before vampires were sparkly, and, for that matter, long before they were Brad Pitt. A vampire was Christopher Lee or Bela Lugosi in tuxedo and opera cape, period.

In D&D, if you wanted to play anything, you ALWAYS started low level and worked your way up. D&D undead had a correlation between type and hit dice; a Skeleton was 1 HD, a Zombie 2, etc, up through Ghoul, Wight, Wraith, Mummy, Spectre, Vampire… so our would-be vampire started, of course, as a Skeleton. But at long last he became a vampire, and then, per the rules, proceeded to make a bunch of slaves by “putting the fangs to them.” Of course, those killed would rise with 1 HD also… as a Skeleton.

Eventually the vampire got a cohort of slave vampires and spectres following him. Hooray.

Well, one dark moonlit night our PC and his henchpires were out travelling somewhere and had a random encounter… another band of vampires. PC decides he’s going to eliminate the lead vampire of the other gang and take them all over; the NPC vampire had much the same idea. And the fight was on.

Vampire attacks Spectre. Vampire hits; Spectre is drained 2 levels; Spectre becomes a Wraith.

Wraith attacks a different enemy, a Spectre, because it’s easier to hit, and hits. But wraiths drain one level, not two, so the enemy Spectre is drained one level… and turns into a mummy.

Oh, by the way… both vampire gangs had been flying, and were fighting at an approximate altitude of 1000 feet above the ground. And mummies are notable for their aerodynamics – “notable” in the sense of, “They fly about as well as a dessicated human corpse that’s had its internal organs pulled out and then been wrapped in bandages.”

And the hapless mummy plummets earthward, flapping its arms madly.

I’m sure you can see where this is heading. The aerial duel continued in something rather like “Night of the Living Dead” meets “Blue Max,” and as the combatants were drained levels, they would eventually hit a non-flying form… zombie, ghoul, wight, or mummy… and go hurtling towards the ground in the grip of that puissant incantation, “9.8 meters per second squared”.

I picture the peasants below, huddling in their wretched huts and praying as hard as they can as various half-decomposed bodies fall out of the sky to land with meaty thumps. On the other hand, all that organic material would be great fertilizer.

I’ve never needed rules for “comic relief” in D&D. Wait patiently and the players will provide it in abundance.
-Mike "Old Geezer" Mornard

Back in the original post, I took the AD&D MM and created a sort of phylogenetic tree, with monsters sorted into categories by HD and best guesses at related monsters.

Well, I went back and combed through the MM II and Fiend Folio, pulled all the monsters out, and created an updated chart. Click through for full size.


Using This Chart

For those of you joining us from other editions, "HD" are actually Hit Dice, the total number of d8s rolled to calculate a creature's Hit Points. Numbers in brackets are either extra HP added on top of rolled HP (+[2]) or total number of hit points ([1-3]) or, in the MM II, fractions of HD for some reason [1/4]. Don't worry about it too much.

This chart includes all creatures, with the following exceptions:

  • Dinosaurs (too many HD, not too useful to list)
  • Demons and Devils (already sequenced by HD)
  • Angels and Divine Messengers (ditto)
Black is the AD&D MM, orange is the MM II, and purple is the Fiend Folio.

It's also a handy list of all the monsters everyone's forgotten... often for good reasons.

Leveling as Anything

Advance upwards each time you level. You can choose to move to a linked creature or stay as your current creature. If there are blank spaces above the creature, it indicates levels that must be gained without change in HD to reach the next creature listed. If an entry repeats, the creature gains an HD as it levels.
If 2 or more creatures share a HD band entry, any one of them can be chosen.

E.g. A 1 HD Vegepygmy levels up. It can choose to become a 2HD Vegepygmy, a 2 HD Barkburr, or a 2 HD Dryad.

E.g. A 3 HD Boar, Wild levels up. It can choose to advance one level towards becoming a Boar, Giant or become a 4HD Lycanthrope, Wereboar.

The blue lines in the 1 HD band connect to the Man entry.

Wait, What?


A 0 HD Man can level to become a:

  • 1 HD Man (Caveman)
  • 1 HD Baboon
  • 1 HD Dakon
  • 1 HD Aarakocra
  • 1 HD Merman
  • 1 HD Skeleton
  • (after waiting a level) 2 HD Lycanthrope, Seawolf, Lesser.
  • (after waiting a level) 2 HD Ogrillion
  • (after waiting a level) 2 HD Gnoll
Not all monsters are connected (it's a bit of a stretch as-is). Wherever possible, descriptions in the Monster Manual like "a distant cousin of" or "related to" were used to place creatures on the tree.

Some of these monsters are utterly forgettable. I've already forgotten what a Terithran is or how it differs from a Denzelian. So many duplicated designs, minor variants, and forgettable monsters. How many pixie-type-things and evil trees can anyone use? So many wasted pages. Still, it was a fun exercise rereading the books and finding unexpected connections.
Lucas Roussel

Life Cycles / Aging

If you interpret HD gain as aging, the charts reveal some fairly strange life cycles. Ogres go through an aquatic stages (presumably as they migrate for spawning?). An ambitious rat can level into a Wereshark. Mature Elves become Marids; mature Gnomes become Night Hags.

Does any of this make sense? Not really. But neither does the story above and that's canon.

Possible 0-Level Characters:

  • Man
  • Rat
  • Jackal
  • Cat (Domestic)
  • Raven
  • Weasel
  • Skunk
  • Squirrel (Ordinary)
  • Kobold
  • Ear Seeker
  • Vilstrak
  • Bowler
  • Mold
  • Oblivax
  • Brownie
  • Bookia
  • Nixie
  • Sprite
  • Leprechaun
  • Atomie
  • Cerebral Parasite
  • Eye, Floating
  • Kilmoulis
  • Webbird
  • Tiger Fly Larva
  • Pernicon
  • Centipede, Huge
  • Galltrit
  • Goblin
  • Bat (Ordinary)
  • Phantom
  • Rot Grub
  • Throat Leech
  • Gas Spore
  • Gorbel
  • Muckdweller
Forget Wizard, Thief, and Fighter. Go with a Brownie, a Rat, and a Tiger Fly Larva trying to make their way in the world. Get rich or get squished trying.


  1. Awesome work !

    I find this interesting because I had a thought recently and I think it fits well here: back in the day, I played some UO RP servers. Some of them had a "tree-branched" leveling up system. So for example, if you decided to be a level 1 Warrior as your starting class, when you reached the XP for level 2, you could become a Cavalier or a Barbarian. Whichever you chose, you would keep the features of the level 1 "class", and added the new ones. Then when you were level 3, if you chose Cavalier, you could become a Knight or something else. What was interesting, is that every class was tied-in with in-game organization or the equivalent: leveling up had a huge impact both socially and mechanically. It was like a mix of very defined archetype class with title per level like OD&D or B/X, but with a "choose your template" aspect of it like GLOG almost.

    The reason I'm bringing this up, is that it seems to really tie in with this "level-up with HD as a monster" with a "choose your path" kind of deal.

    Maybe it would be possible to bring back the title, and give them a bigger impact on the gameplay in terms of feature, IDK. I'm just brainstorming here !

  2. This is amazing, you put a lot of work into this! I wonder if there's a way to publish this in some form without infringing on the copyright.

    1. I'm planning on putting a simplified form into the Monster Overhaul book.
      Someone else could probably publish a full version if the non-OGL creatures (Beholder, Umber Hulk, etc) were removed.