Grognard's Corner

Grognard’s Corner: THAC0 and other esoteric goodness

Grognard's CornerWelcome to Grognard’s Corner, wherein Shane channels his inner grognard and talks about the good old days and likely rants a bit and carries on.


Now there was a rule. Back in my day Armor Class (AC) went in reverse and there was this thing called “To Hit Armor Class Zero (0)”, AKA the famous THAC0 rule.

The lower your THAC0, the better. The lower your Armor Class (AC), the better. They worked together, hand in hand. Not that hard to keep straight, despite what later designers want us to think. The pansies.

THAC0 calculation table

Ya look there, then ya look there, and boom

It was pretty straightforward. The lower the AC, the harder to hit. Every class had a THAC0 relative to their level. Literally, that number is what you had to roll or better to hit someone with an AC of 0. Lower than zero? Add one to the “to hit” number for each number lower. AC higher than zero? Subtract one from the to hit number for each number higher. Simple, kiddos.

These modern difficuly checks against armor classes that go up when they get better. Hmph. Namby pamby coddling madness for the huddled, lazy masses.

Skeleton monster manual listing

THAC0’s so simple even a skeleton with a hole in his head has one

THAC0 and its related calculations was all part of the mystery and sense of belonging of playing Dungeons & Dragons when it was still wild and untamed.

Sort of a rite of passage, being willing to learn rules that might or might not make sense. Poring over the books and figuring it all out. Knowing you would need to refer to a table. Looking up tables was fun. It was something you knew that the muggles didn’t know. ‘Course, we didn’t call them muggles then. They were just the folks that weren’t us.

Everything didn’t have to make sense. For years a wizard (sorry, “magic-user”…. wizard was a title at 9th level for a m/u) simply could not use a sword unless he multiclassed in AD&D… and in basic (non “Advanced”) Dungeons & Dragons, a wiza– magic-user — wasn’t going to use a sword, period. If you wanted to cast spells and use a sword, you chose the class of “Elf”… that’s right, Elf as a class, not a race. And we LIKED it. Uphill both ways in the snow.

Classic d&d elf and magic user advancement table

That’s right, it’s an Elf *class*, young’n

The rules tried to explain it all away with a comment about magic-users not being able to use a sword because they had spent so much time studying magic, but really… it was game balance, trying to keep things fair between classes. And that was OK, we didn’t care. At least I didn’t. It was just how it was. Another part of “the game”, the coolest game.

Those early rules stuck with me and became ingrained into how I perceive D&D and the world around it. I remember reading a book several years ago that was based in a D&D setting and a wizard used a crossbow. Nope! I immediately thought, best thing that wizard can do is use a dart for a ranged weapon. What is the author thinking? How did the editor not catch that? But then I remembered, by that point we were in 3rd Edition and sanity and all things right had gone out the window. THAC0 was gone and the foundations were crumbling.

And saving throws? Oh man, the saving throws. Listen to this litany of esoteric goodness: Paralyzation, Poison, or Death Magic; Rod, Staff, or Wand; Petrification or Polymorph; Breath Weapon; Spell… Oh, momma.

1st Edition AD&D Saving Throws

Music to my ears…

Yeah, yeah, I know, it “makes more sense” to do saving throws by ability score, but let me ask you… which way sounds more mysterious and interesting? Which way really fires up your imagination the first time you look at a character sheet? No contest for me, young buck.

Skills? Nobody but a thief had them. Proficiencies and feats? What? No need… ima gonna smash you in the face without them with my mace (because I’m a cleric and can’t use edged weapons, period). It all fits together, it’s how this beautiful gaming system works.

It’s just. It’s just… it’s just that there was something more interesting to me about the older versions. The weird rules and stuff that were hard to learn or that weren’t intuitive was part of the charm, part of the fun.

Ya had ta earn it.

Newer editions have definitely refined and improved the game and become more accessible, and unlocked some of the boxes characters used to be locked in… but at the same time we have traded off something else. A class of esoteric knowledge that only the fellow geeks (the initiated) knew, that helped us identify with each other.

In the 70s and 80s and heck even early 90s there was none of the “geek chic” that exists now, we caught all kinds of hell for being nerds and the murky, somewhat inscrutable world of Dungeons & Dragons and other RPGs was ours. We didn’t care if just anyone could access it in 5 minutes.

Times change. People change. Games change.

But my love of THAC0 and other foundational D&D mysteries never will. If you weren’t there, I wish you coulda been. Spend an extra moment looking up the THAC0 before you roll that next twenty sider… it won’t hurt as much as you think, and you might even like it.

5 thoughts on “Grognard’s Corner: THAC0 and other esoteric goodness

    1. Shane Post author

      I don’t dislike d20, but bring on some THAC0 baby!

      And remember DM Cal, nothing good shambles.


Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.