THAC0
- Thread starter Azzy
- Start date
ezo
Hero
Fair enough. My opinion is they are not the same thing.
The Scythian
Explorer
After its use in the DMG, the earliest use I'm aware of is the RPGA AD&D tournament module R1 - To the Aid of Falx from 1982. It's used in monster stat lines.
darjr
I crit!
Nice! Found where Frank Mentzer mentioned it in Dragons foot.
That thread also points out that Peterson found it mentioned in A&E #31 by UCLA folks.
To Hit Armor Class Zero
The die roll value required for an attack to hit an armor class of zero, or "THAC0," is the signature combat mechanism of the second edit...
playingattheworld.blogspot.com
The Scythian
Explorer
Good find. According to that threat, it looks like the first post-DMG use in a TSR product was likely Polyhedron #4 in January 1982. Also, that Alarums and Excursions link is cool.Nice! Found where Frank Mentzer mentioned it in Dragons foot.
That thread also points out that Peterson found it mentioned in A&E #31 by UCLA folks.
To Hit Armor Class Zero
The die roll value required for an attack to hit an armor class of zero, or "THAC0," is the signature combat mechanism of the second edit...
View attachment 396367
Parmandur
Book-Friend, he/him
Here's the thing about THAC0: it I'd ftpm before my time, I started with 3E. But after we burned out on 4E, a friend did run a shortened 2E game (we TKed t Giant Rats, good times). I was shocked by how awesome the THAC0 bell curve was, much better than the Infinite scaling of numbers in 3E. Them when 5E came along...the math is the same as THAC0, just upside down from 10-30 instead of 10 to -10.
Mannahnin
Scion of Murgen (He/Him)
Two tidbits:
1. While THAC0 did appear in those earlier instances, technically the mechanic was a bit different, because officially in 1E the attack matrices had six repeating 20s. For example, a 1st level Fighter hit ACs 0 to -5 on a 20, but needed a modified 21 to hit AC -6, through a modified 26 to hit AC -10. This went along with there being no auto-hit on a natural 20 or auto-miss on a natural 1 rule in OD&D or AD&D 1E.
2. While OD&D and AD&D (prior to 2E in 1989) officially used attack matrices/tables instead of a THAC0 calculation, we learned from historians in 2018 that the pre-publication draft of OD&D DID use a simple +1 improvement per level rate for Fighters. It turns out that the tables appear to have been used for the sake of familiarity to wargamers (since all or almost all wargames at the time used attack tables), and then the progression was broken into "chunks" due to space limitations on the page!
1. While THAC0 did appear in those earlier instances, technically the mechanic was a bit different, because officially in 1E the attack matrices had six repeating 20s. For example, a 1st level Fighter hit ACs 0 to -5 on a 20, but needed a modified 21 to hit AC -6, through a modified 26 to hit AC -10. This went along with there being no auto-hit on a natural 20 or auto-miss on a natural 1 rule in OD&D or AD&D 1E.
2. While OD&D and AD&D (prior to 2E in 1989) officially used attack matrices/tables instead of a THAC0 calculation, we learned from historians in 2018 that the pre-publication draft of OD&D DID use a simple +1 improvement per level rate for Fighters. It turns out that the tables appear to have been used for the sake of familiarity to wargamers (since all or almost all wargames at the time used attack tables), and then the progression was broken into "chunks" due to space limitations on the page!
Nikosandros
Golden Procrastinator
Nice, I didn't know that. Personally, when I re-started playing AD&D (about 20 years ago, now), I "smoothed out" the attack and saving throw tables and, later, I did the same for OSE.
darjr
I crit!
In the case for the A&E article I don’t think 1. is correct, it looks like they did away with the table and used thac0 just like later folks do.
In fact I’d argue that the very calculation of a thac0 doesn’t include the repeated 20s at all.
Sacrosanct
Legend
Officially AD&D 1e was like @Mannahnin said, however our group, and every group I saw, ignored that and pretty much used the THAC0 method from as early as I can remember (I started in 1981). Just like we ignored a bunch of other official rules like weapon vs. armor. I think it really is divided among two groups back then:
1. wargamers who moved on to D&D, which seemed to use a lot more of those tables and rules because they were more familiar with them
2. gamers like me who started after D&D came out, and saw all those tables as impediments to the speed of game play and fun, so we only used the rules we wanted and streamlined everything else that we could.
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