In 2016, on his blog Tales of the Grotesque and Dungeonesque, Jack Guignol wrote:
So, the characters in your old-school D&D game go somewhere you haven’t yet prepared and you describe some cool, weird-ass monster that you don’t actually have stats for […] In situations likes these, I just use the stats for a bear and no one is the wiser. Re-skin appearance, methods of attack, and add special abilities on the fly if you absolutely must...but when in doubt, just use bears.
Wise words: good, blessedly simple advice that does not need improving.
Nonetheless, many have tried to improve it.
Dice Goblin wrote Just use Bears…. Or Wolves, or Spiders, or Tigers (nominated for the bloggies, congrats!), and made a great mini bestiary to go with it.
Leicester’s Ramble made a build-a-bear system.
Night Noon Games made a great zine built on a similar principle.
So that is the ring, and this is my hat; there are others like it, but this one is mine. And because my whole deal is index cards, it fits on a handy index card you can print (and put in your Screen of Holding).
Just Use 3x5 Bears Index Card Tool
Works for roll-high, D20-based systems (like Shadowdark).
To make any monster, pick a number, 9-18. That’s it.
That number, the MonsterDC, is its AC, its HP, and the DC of the Saves / Contests / etc it provokes. The MonsterDC-10 is also its Attack Bonus.
Fine-Tuning
If you want to fine tune a monster on the fly, you can
drop or raise HP
account for things like gear
give it a special ability or two
if it’s nasty, give it extra attacks.
You usually won’t need to know a creature’s stats. But if you find that you do (fighter tries an opposed STR roll?), take the ATK+ and split it among abilities as you see fit. To make more flavorful monsters, introduce negative numbers to buy more bonuses.
Example Stat Lines
These show what it would look like if you bothered to write out the whole stat line based on one number. They lack special abilities.
DC 12 Warrior
HP 12, AC 12, DC’s 12, ATK +2 D8
+2 STR (balance: +2)DC 12 Wild Animal
HP 12, AC 12, DC’s 12, ATK +2 D8
+3 STR, -3 INT, and +2 WIS (balance: +2)DC 12 Wizard
HP 12, AC 12, DC’s 12, ATK +2 D8
-2 STR, +3 INT, +1 CHA (balance: +2)
+ Some SpellsDC 18 Warrior
HP 36, AC 18, DC’s 18, ATK: 3 Sword (+8 1d12) (2x HP, 3 Attacks)
+4 STR, +4 Dex (balance: +8)DC 18 Wild Animal
HP 18, AC 18, DC’s 18, ATK 2 Claws (+8, 1d12) (2 attacks)
+4 STR, +3 Dex, +4 CON, -3 INT (balance +8)DC 18 Wizard
HP 18, AC 18, DC’s 18, ATK 1 Magic Dagger (+8, 1d12)
-2 STR, +2 Dex, -2 CON, +4 INT, +2 WIS, +2 CHA (balance +8)
+ Some Spells
Comparison to Published Monsters
The Attack Bonus (ATK+, or MonsterDC-10) is also roughly equivalent to the HD rating from other common systems.
For you nasty spreadsheet freaks like me (who won’t be able to sleep until you know how this method stacks up against canonical monsters in different systems!) I made you this thing: Just Use 3x5 Bears vs Published OSR Monsters. Sweet dreams!
Now go make some slimy, tentacled, electric bears!