I'm Stealing This Monster Stat Block

A Brilliant GM Technique by Will Purves

Sometimes, you’ll come across an idea so good it demands sharing right away. Over at the Copy/Paste Coop Discord, we were discussing how monster HD (Hit Dice) provides a lingua franca for the OSR, making it easy to translate adventure modules between systems, and how modern post-OSR games like Into the Odd no longer have that benefit despite sharing a common ethos and ancestry with the movement.

Will Purves of FaeCraft fame shared his system-agnostic way of designing monsters, and he gave me his leave to post it here.

This is what Will’s monster stat block looks like:

The big circled number is the monster’s Danger Level (a number between 1 and 10). Will converts it on the fly to the system at hand:

• For a D&D-ish system, this converts to the monster’s HD.

• For Odd-likes, it equals the monster’s HP, and monster strength is derived from it by adding 7 (so the spider from the pic would have 2 HP and 9 STR).

It immediately made me think of examples for other systems:

• For The Electrum Archive, this number could equal the monster’s Skill, and it could be doubled to get HP.

• For Swords of the Serpentine, this could be equal to Refresh Tokens granted for defeating it, and its Malus would be 5 times that number.

• etc.

It’s remarkably easy to create conversion rules and use the same “stat block” regardless of the game played.

Even more interesting are Diegetic Abilities, i.e., the various options listed with a question mark. What Will does when players encounter a monster is roll a bunch of d6es: for each 1-3, the monster doesn’t have one listed ability, and for each 4-6, he does have it.

So one spider might end up being bigger, and be camouflaged. Another might be a zombie spider in a web network lying in ambush. How these abilities translate to mechanics depends on the specific system. (E.g., they might add armor, more HP, a poisonous attack, etc.)

As part of his prep, Will picks out the cards that seem potentially relevant, and puts them into a deck that he takes to the table. For random encounters he draws one or two, and for set pieces he pulls out the card needed. If it is a creature that might reappear or if there are others in the vicinity, the card goes back in the deck.