urknighterrant: No. It was included in the original 1st edition AD&D PH.
For example, if you were attacking a man in plate mail your weapon would have a modifier vs AC 3. It would be like a -4 for a dagger or a -1 for a long sword. A morning star, mace, or flail, on the other hand might have a +1 (I'm not looking up the actual stats here but you get the idea). The individual bonuses and penalties for each weapon were on the weapons tables.
There were a lot of problems with this system. The same modifier would apply whether you were attacking a man in banded or a man with full chain and shield (ac 4), two VERY different armor types. The results, therefore, tended to come across as rather arbitrary. Also, things like magic bonuses and dex bonuses could create confusion when facing bosses and tier 1 encounters.
And then there were the butthurt howls of prestidigitaters trying to penetrate heavy armor with staves and daggers.
They were a good, albeit flawed, mechanic in theory and I'll wager they were applied in Baldur's Gate. But in a tabletop setting they just weren't worth the headache. They slowed down the game, created rancor at the table (when the DM would declare that an ankylosaurus has an AC equivalent of 3 there was plenty of butthurt to go around), and didn't really add anything to it. Eventually pretty much everyone just ignored them.
By the time the DMG came out the only treatise it got was a short, almost apologetic descriptive paragraph detailing when the bonuses should and should not be used. Later, when full plate became a "thing" and alternate armors like brigandine and breastplates became available the system was just allowed to die quietly. No attempt was made to expand it and include the new armor types. Likewise, as new weapons were introduced they tended to be presented without To Hit vs Armor Class Modifiers.
I'm no expert on 2nd edition but I'm pretty sure they dropped it completely. I don't recall seeing any TH vs AC modifiers in the Arms and Equipment guide.
Ah, I'd almost forgotten about that chart. I'd heard about it while reading up on 2E, and I would have quickly dropped it were it an option. I appreciate the intent behind it, but it's yet another number to keep track of that slows combat down and yet another variable for dedicated twinks to try to screw the system in the ear. Funny thing is that supposedly, 2E's abandonment of the concept is why 2E has so many weapons listed in the core books that have stats that are markedly inferior to some of the more popular ones with regards to speed factor and damage output.
Oh, before I forget, I'm starting a new thread in the general forum regarding the Tomb run. I'll link to it as soon as it is written.
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