Where was the term THACO first used?

[Henry]

So true. In fact, my uncle's best friend was attacked by a chupathac0 while visiting Mexico in the early '50's. The press hushed it up, though.

There is no such thing as a Chupathaco; don't spread crazy rumors. Most sightings are actually the Thacomonkey, native to Brazil, often known for throwing its small, d20-shaped feces at passers-by.

 

[Plane Sailing]

for our campaign there was no AC 0 for PCs prior to UA. we used weapon vs armor type.

We used weapon vs armour type too, but based it on the type of armour (heh) rather than the numeric value. So someone in +2 chain and +2 shield was AC 1, and weapons had their appropriate bonuses for use against chain.

We never did this for monster AC though, since it wouldn't have made sense. We created a separate weapon vs monster protection to cover things like fur, scales, plates, shell, incorporeal and elemental 'types' of protection, and extrapolated from the existing chart.

One of the things about the weapon vs armour type tables was the HUGE bonus that open hand got against AC9 (which was no armour in those days). +4!

Cheers

 

[WayneLigon]

The first place I saw the abbreviation in print was in the early Judges Guild stuff; I would think they adopted it from the fan press of the day.

 

[dcas]

A friend of mine had a PC named Thac0. Thankfully Thac0 had his skull split open by a carniverous ape and died.

 

[SWBaxter]

What we have here is essentially the 3e formula with reversed numbers and substraction. I am curious whether this method was commonly used in the USA - I always figured it was, but to my surprise, people are constantly quoting the other, less efficient formula... which, granted, was how the 2e PHB worded the rule.

We always used this method. I've always been kind of amused by the "THAC0 is teh DEBIL!!!" meme in 3E marketing, since the 3E method is almost identical to me. Different strokes for different folks, I guess.

While the concept is in the 1E DMG, I think the term was first used in fanzines and third-party products, in order to provide relatively complete combat stats both for DM convenience and to avoid reprinting TSR's charts. TSR at that time had already earned the "They Sue Regularly" nickname, so other companies were learning to cover their butts.

 

[tzor]

I never used THAC0. (In 1E) I feel so deprived.

Honestly, our gaming group at RPI always thought of it as a table, especially because of the repeating 20's so we always looked it up for the most part. Then again, we were strongly influenced by the other table driven products of the time like Arms Law/Claw Law and we were constantly making even nastier non linear tables.

You want to hit it? You will need an (00) (00) (01) then.

 

[BOZ]

We used Melan's method, but then I'm from the UK.

we did the same thing in 2E.

 

[Staffan]

To figure out the success or failure of an attack, take the character’s THAC0 (figuring in to hit modifiers if applicable) and substract 1d20. The result is the Armour Class your attack hits. For example: a Fighter with 18 THAC0 rolls a 12 on the 1d20, hitting an AC of 6 (18-12=6). If the same fighter had rolled 18, he would have hit AC 0 (18-18=0), and if he had rolled 8, he would have hit AC 10 (18-8=10).

That's how we did it too back in 2e. We also made sure to include permanent attack modifiers (e.g. Strength/Dex, weapon specialization/expertise, magic) in the adjusted THAC0 - I think this may have been one of the things that tripped some people up. Saying "AC hit = THAC0 - d20" is one thing, but "AC hit = THAC0 - (d20 + mods)" gets complicated because you're involving both additions and subtractions in the same calculation.

My character sheets had a THAC0 box that included:
Base THAC0
Str mod
Melee THAC0
Dex mod
Ranged THAC0
Thrown THAC0 (using both Str and Dex).

I also had a column named THAC0 in the weapon table, where you included weapon-specific adjustments.

 

[Griffith Dragonlake]

Judges' Guild invented THAC0

I'm fairly certain that THAC0 was used by Judges' guild prior to 1e. I distinctly remember playing OD&D (White Box) with some Judges' guild weapon cards and THAC0 tables in Spring/Summer of 1978.

 

[occam]

Where was the term THACO first used? Or, if you wish to reframe the question, when was it first used?

I don't remember the term being used prior to 2nd Edition AD&D. I'm sure the concept was around, and maybe it was used somewhere else, but I could SWEAR that it was not made part of the core rules set until 2nd Edition AD&D.

I know there are going to be people who believe with all their heart and soul that this appeared in 1st Edition, but can any of them show me where?

The first time I saw "THAC0" used was in one of the Tracy & Laura Hickman modules, so that would've been either Ravenloft (1982), Pharoah (1983), or Dragons of Despair (1984). I'm pretty sure it was in the first Dragonlance module, but I'd have to check to be sure, and I don't have those with me at the moment. That may have been TSR's first use of the term.