Friday, June 19, 2026

Below Gwarnath: Bestiary – Converting "All the World's Monsters" to OSRIC (Part 1)

In developing my own stocking tables for the megadungeon, I want to incorporate not only AD&D/OSRIC monsters (including Monsters of Myth), but also thematic creatures from other sources like the Fiend Factory/Folio, Monster Manual II, Gamma World/Metamorphosis Alpha, Dragon Magazine, etc. I also want to use the classic, 3-volume "All the World's Monsters" from 70s-era Chaosium.

ATWM Vol. I

For those not familiar with that series, ATWM was a collection of monsters from various homebrew sources. Many of the authors are rando contributors, but quite a few are luminaries of the early scene. In addition to being edited by RuneQuest designer Steve Perrin and Jeff Pimper, contributors included Dave Hargrave, Lee Gold, Paul Jaquays, Steve Marsh, Glenn Blacow, Steve Henderson, and Clint Bigglestone.

I was introduced to the ATWM books via my high-school DM's megadungeon, Darconea—a 20-level stack of Dungeon Geomorphs. The DM used lots of ATWM monsters throughout the dungeon, and they provided many harrowing battles and persistent nuisances. Several of the monsters (Doomguards, Gnomes of the Yippurai, Scrubbing Bubbles) became frequently-encountered elements of the dungeon's ecosystem. 

The books were landscape-oriented, written in all-caps, dot matrix letters, and featured crude ink drawings of some (but not many) of the crazy creatures. The stat blocks (example at right) were atypical of D&D, most notably featuring dice ranges for Intelligence and Dexterity, and frequent use of non-d8 Hit Dice that sometimes scaled to make the monster tougher. The stat blocks include details on encountering the creature (lair, wandering, treasure type, etc.) Armor Class is sometimes also a range, or has unexplained modifiers.

The mechanical ranges for the various stats often lack game-logic and seem up to the designer's whim. Some of the numbers get absurdly high. No real explanation is given in this book as to the mechanics of the system the monsters are designed for (maybe OD&D?). Volume II describes the "Perrin Conventions," which was an alternative system of OD&D used by West Coast players (similar in many ways to Dave Hargrave's Arduin system) and, I presume, the native system for these books as Jeff Perrin is the series' editor. Later ATWM volumes also give instructions for converting the stat blocks to RuneQuest and Tunnels & Trolls. I'll discuss the example monster above a little later, as it is on my Level 1 list. I'm sure all the vagueness is related to copyright law and early TSR's eagerness to squash any unlicensed third-party products.

Once I started DMing and learned more about how the AD&D system actually worked, I realized that most of the monsters are horribly designed and mechanically broken. The system is only OD&D-adjacent and seems to bear little resemblance to the mechanical underpinnings of that game. It also bears little relation to Chaosium's alternative-D&D game: RuneQuest. The stat blocks are wildly inconsistent and the dungeon levels assigned to some of the monsters are totally out of whack. You have to adapt all these monsters to D&D standards to use them properly.

Despite the books' many flaws, and though many of the monsters are complete garbage, there are still quite a few unpolished gems sprinkled throughout all three volumes. I want to take these diamonds-in-the-rough and convert them to OSRIC in a way that retains the core creative idea but fixes their broken or half-baked mechanics.

Each ATWM book contains tables of its monsters by creature type, terrain, and dungeon level, so I made lists of the monsters by levels 1–3 (for starters), and then I read them carefully to figure out which ones I wanted to convert for use. I'll discuss each one, but I'm not going to bother converting all of them because many aren't worth it. Not necessarily because they're bad, but because they're pointless or redundant with existing monsters. But make no mistake, a lot of them are just terrible.

This post will deal with the listed "Level 1" monsters from All the World's Monsters, Volume I (according to the index):

  • Demon, Serpent (Lesser)
  • Goblin, Glass
  • Kill-Kill
  • Maggot, Mind
  • Plink Plant
  • Weakling
  • Worm, Mind

Several of these monsters are quite deadly for 2nd and 3rd-level characters, much less 1st (if we take the given that "dungeon level" equates roughly to "character level"). When I choose the monsters I want to use and then convert them, I will definitely realign their xp value and level designation. Let's dive on in...

Below Gwarnath: Bestiary – Converting "All the World's Monsters" to OSRIC (Part 1)

In developing my own stocking tables for the megadungeon, I want to incorporate not only AD&D/OSRIC monsters (including Monsters of Myth...