OSR: What to Include in the Monster Overhaul?

My latest project, the Monster Overhaul, is going splendidly. Here are some disorganized thoughts on monsters, layout, and choices.

Part 1: Design Notes

"Canonical" Monsters

The chupacabra, the Mexican goat-sucker, first appeared in 1995. 1995! The first "eyewitness" account described a sort of lizard-like phosphorescent clawed humanoid alien. As early as 1997, the chupacabra had mutated into fanged hairless dog, sometimes winged, sometimes not.

Or consider the obscure Celphie, a "five-legged bovine with human hands", which A Book of Creatures painstakingly traces through the ages to a very surprising orgin. Which of its many transformations is "correct"?

In the classic AD&D Monster Manual, thanks to the dubious influence of Edward Topsell's History of Four-Footed Beasts and Serpents, the Gorgon is famously conflated with the Catoblepas. Should I list both? Include a cross reference? Or strike it out as an error and move on?

Stories are inconsistent. Creatures that are demons in one tale are flesh and blood in the next. Unique examples become species; species become individuals. Vital elements appear or disappear. Should the Medusa be winged? Should the Manticore be intelligent or bestial?

There are no easy answers.

Over the centuries, mankind has tried many ways of combating the forces of evil... prayer, fasting, good works and so on. Up until Doom, no one seemed to have thought about the double-barrel shotgun. Eat leaden death, demon 
-Terry Pratchett

The Origin of Species

It sounds trite, but mythology was not written for RPG purposes. Creatures were written, adapted, or changed for specific reasons, but until very recently those reasons did not include "What happens if some imaginary people in a collective story framework bolted to a random number generator encounter this monster?"

Monsters of Warning

Bugbears, boogeymen, lamia, and other night terrors say "Don't go out at night, child, or you'll be eaten." The Minotaur, the Anaye, the Wendigo, and other unnatural creatures say "Don't break these taboos."

Monsters of Explanation

What are those strange lights in the bog? Why are trees shredded by the wind? Why do drowned corpses look like that?

Monsters of Translation

Like the Cephie listed earlier, many classic monsters are victims of enthusiastic translation. An obscure word in one version becomes something entirely new in a later collection. Citations are not provided, or if they are provided, aren't pursued. Over the centuries creatures grow stranger and stranger.

Monsters of Allegory

This temple is protected by a mighty guardian: the head of the wisest creature (man), the body of the strongest creature (bull), and the wings of the swiftest creature (hawk). This spaceship is haunted by a terrifying predator: the [redacted for sanity purposes.] The noble knight encounters Want and Despair, incarnated as a giant vole and a three-headed serpent for some reason.

The Bestiary of Christ, one of my favorite reference books, is entirely concerned with the allegorical implications of beasts both natural and fictional, and rarely distinguishes between them.

Function and Form

The first RPG monster lists were simple wargame stats. "Fights as two Fighting Men", etc. Numbers without words or context.

The first Monster Manual combined wargame stats with a medieval, or Borgian, bestiary. Creatures were described. Colours, lairs, and details were provided. It's an innovation. A birding guide doesn't typically tell you how hard it is to fight a goose; a medieval bestiary doesn't specify the treasures hoarded by a Sphinx.

In growing closer to a bestiary, the Monster Manual also acquired extra baggage. Creatures were included because they existed, not because they were useful. Not all fictional creatures need stats. A one-winged bird that flies in a spiral is interesting, but does it need rules? Choosing which creatures to include and which to ignore is difficult. 

Later books duplicated and triplicated entries. The AD&D Monster Manual II is a particularly egregious book: Raven, Raven (Huge), Raven (Giant), Swan, Vulchling, Vulture, Vulture (Giant), Cat (Domestic), Cat (Wild), Weasel, Skunk, and three different kinds of Squirrel!

Or the endless profusion of small fairies: Atomie, Bookia, Brownie, Buckawn, Grig, Gnome, Leprechaun, Nixie, Pixie, Quickling, Sprite, and Xvart.

In taxonomy, there are lumpers and splitters. When it comes to monsters, I'm a lumper. If a creature can be represented with the same stats, it should appear in the same entry. No two monsters in the Monster Overhaul will feel identical, or (hopefully) even close to identical. Writing a list of 200 monsters is not difficult. Writing a list of 200 completely different monsters, each deserving of rules, is tricky.


Originally, I wanted the "People" chapter to be entirely setting-less, but none of the drafts worked. I had to pick a centre point. Starting with generic medieval-ish tropes and spiraling outwards created a set of tables and stats that, while adaptable to many settings and game modes, still had enough flavour to be useful.

I want to avoid a sense of "othering". Splitting monsters into categories based on their cultural origins would be ridiculous. There used to be elephants in Crete and lions in England. Some entries have a "legendary abilities" table; I've raided real world myths and stories for suggestions, then filled in the blanks with plausible inventions. Some of the myths are very obscure. Finnish folk-tales get paired with Haida proverbs; in come cases, after translation, the say the same things.

As stated above, every adaptation of a monster changes the monster. Mythological creatures are in flux; even real-world creatures gain and lose connotations. It used to be care, not curiosity, that killed cats. In mangling monsters to fit an A4 spread and OSR numbers, I'm participating in an ancient tradition. I'm trying to mangle everything with approximately equal attention. Angels get the same treatment as Kappas.

Equal doesn't necessarily mean fair, but I suspect it's close enough for the purposes of this book.

Part 2: Organizing 200 Monsters

There is no description of the universe that isn't arbitrary and conjectural for a simple reason: we don't know what the universe is.  
-Jorge Luis Borges

I cover my choices in more detail in this post, but the Monster Overhaul will be split into 20 sections of 10 monsters. Alphabetical order is great for finding a monster in a hurry. It's useless for anything else.

Here are all the completed entries as of today. Most of them are available on Patreon.

People Sci-Fi Elemental Thinking Beasts Heraldic Beasts Hot Plains Hostile Forests
1 Adventurer Alien Invader Elemental Harpy Basilisk Baboon Bear
2 Barbarian Alien Visitor Elemental Spirit Kappa Catoblepas Crocodile Boar
3 Cultist Alpha Brain Elemental Tyrant Lamia Chimera Elephant Dryad
4 Knight Doppleganger Firebat Lammasu Cockatrice Flightless Bird Fairy
5 Mercenary Giant Insect Gargoyle Manticore Griffon Hive Insect Giant Snake
6 Peasant Perfect Predator Grue Medusa Hydra Hippopotamus Tiger
7 Pilgrim Robot Hound Living Gem Minotaur Owlbear Hyena Treant
8 Merchant Robot Servant Sandwalker Naga
Jinn Troll
9 Townsfolk Robot Titan Spitling Peryton
Lion Unicorn
10 Wizard Veggie-Mite Will-o-the-Wisp Sphinx
Rhinoceros Wolf

Tabulated like this it seems like a depressingly small list, but the current PDF runs to ~100 pages.

Consider that most of the entries in the Elemental chapter cover 8 elemental variants, or that Griffon covers pretty much every hybrid non-chimerical beasts, or that Fairy encapsulates (what feels like) twenty different D&D monsters on one 2-page spread.

To make a setting, pick a handful of chapters. If you need a random encounter, roll for a chapter, then roll on that chapter's encounter table. Yes, each chapter has 3 encounter tables (one for lone monsters from the chapter, one for two or more monsters from the chapter, and one for a monster from the chapter and a monster from a different chapter).

The book will also contain alternative methods of organizing monsters. The full alphabetical index, which includes all the entries plus all named variants plus all monsters the stats could plausibly be used to represent, is going to be a thing of beauty.

Part 3: Art

The Monster Overhaul is going to be a massive book. That means it needs massive art.

I'm a firm believer in text over art. If I can fill a page with text, I will. But sometimes I can't come up with a tool that fills the space neatly. Sometimes, a monster cries out for an illustration.

I'm very picky when it comes to artists, but I'm slowly assigning chapters and planning sections.

Confirmed Artists:


Frenden's taking on the Sci-Fi chapter. Their pedigree includes work for Mystery Science Theater 3000... and Magical Murder Mansion.

Dyson Logos

What's a Minotaur without a labyrinth? A cult without a lair? A wizard without a tower? Maps for the Monster Overhaul are provided by the incomparable Dyson Logos. Some are off-the-shelf maps with light edits, but quite a few are exquisite custom pieces.

Potential Artists

I don't want to confirm these artists yet because no money's changed hands, but most likely, if all goes well:

Lucas Roussel

Do you really need an explanation as to why I'm incredibly excited to work with Lucas? I turned some of Lucas' art into a free bestiary here.

Robin Carpenter

Robin has just successfully funded their first Kickstarter. If you're reading this before March 11th, you've still got time to back it!

I haven't put out an open call for artists, but feel free to drop a link in the comments or send me a direct message on Twitter if you're interested. I'm very picky.


  1. I am super excited for this book. The origin of species heading is also super handy for brain movement.

  2. This book is shaping up to be one of the most useful adventure design tools I've ever come across. Really looking forward to seeing the rest of it.