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OSR OSR, Ascending AC or no?

How critical is descending AC in an OSR product?

  • Yes. It's what I prefer in an OSR D&D game

    Votes: 11 22.4%
  • No, it's not needed and/or I don't want it in an OSR D&D game

    Votes: 30 61.2%
  • I really don't care either way

    Votes: 8 16.3%

  • Total voters
    49

Sacrosanct

Legend
@Bacon Bits brought up an interesting and fair point* in another thread, and I wanted to expand on it for it's own topic. I'll be creating a poll. For obvious reasons, this poll should be answered by people who are fans of the OSR as general rule, because the responses will hold the most value. I.e., if someone couldn't care less about the OSR votes, then it doesn't help me identify what OSR fans want. So thanks for respecting that request.

so the question: How necessary is it to have descending (THAC0) in an OSR D&D product that is not a direct clone of any one edition. Rather, a version that is simply meant to capture the feel and aesthetic of early D&D.

*Bacon Bit's quote:
I don't see the point in using an OSR system unless it eliminates descending armor class by default. It's the line between an old school reprint and an old school renaissance.
 

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Esbee

Explorer
Yay! I get to be the contrarian here!

I say keep descending values and THAC0, it's a far superior system to the ascending ACs, and less work overall for DMs.
 

FaerieGodfather

Aberrant Druid
Thread title and poll question mismatch.

I prefer ascending AC. They're mathematically identical, but ascending numbers are just easier for most people and I'd rather spend my time and energy at the table on things that are more important.
 


Sacrosanct

Legend
Please explain. I've always seen descending values and THAC0 as more work for players and DM, not less.
It’s because the prework is done on the THAC0 table. That is, on most AD&D character sheets, each weapon has its to hit chart listed, so when you roll your attack roll for a particular weapon, you see immediately what AC you hit. There’s no math during the actual combat segment of the game

For example, if I have a +2 bonus for strength, and a +1 bonus for magic weapon, and my base THAC0 is 17, it’s already on my sheet I have a THAC0 for that weapon of 14, and every other AC as well. So if I roll a 10, it’s right there on my sheet I hit AC 4. No need to add 2 then 1 to my die roll.
 


It’s because the prework is done on the THAC0 table. That is, on most AD&D character sheets, each weapon has its to hit chart listed, so when you roll your attack roll for a particular weapon, you see immediately what AC you hit. There’s no math during the actual combat segment of the game

For example, if I have a +2 bonus for strength, and a +1 bonus for magic weapon, and my base THAC0 is 17, it’s already on my sheet I have a THAC0 for that weapon of 14, and every other AC as well. So if I roll a 10, it’s right there on my sheet I hit AC 4. No need to add 2 then 1 to my die roll.
See, that's not easier to me. Looking at a table versus adding a single number? I can add two two-digit numbers by the time my eyes leave the d20. Much faster than then taking that roll and looking at a row on a table.

But, if its faster for someone else that's fine too I guess. But that table can just as easily be ascending or descending. It doesn't matter if you're looking at a table. So in short, to me, never been an advantage to descending, but their can be one for ascending.
 

Zardnaar

Legend
Not needed at all. Maybe for an outright clone. I can use THAC0 but prefer not to.

Ascending is also easier for new players since recruiting 5E players us the easiest.

New players struggled with THAC0 ran 2E with ascending they liked it.
 

It depends.

1. If each AC is connected to a distinct armor type (AC 7 is always leather armor or fur, AC 5 is always chain mail or scales, AC 3 is always plate mail or shells/etc.), I prefer descending AC. (For those interested, see Isle of the Unknown by Geoffrey McKinney)

2. If AC is just a number that abstractly describes how hard someone/something is to "hit", I prefer ascending AC.
 

Charlaquin

Goblin Queen
I’m not an OSR gal and I haven’t played any pre-3e editions of D&D (and accordingly, didn’t vote in the poll), but I will say this for THAC0: if you tell the players their target’s AC (I know, probably not something most OSR DMs are wont to do), it allows them to do the math first and figure out what number they need to roll to hit. This changes the process of rolling to hit from:

1. Roll the d20
2. Add your to-hit bonus to the result
3. Compare the result to the target’s AC to find out if you hit

to

1. Compare your THAC0 to the target’s AC to find out what number you need to roll on the d20 to hit
2. Roll the d20 to see if you hit

The latter makes for a (subtly) more psychologically satisfying experience of rolling to hit, due to having a more traditional engagement curve. By removing the extra step of calculating the total on your to-hit roll, the process of rolling becomes the climax of the attack roll, with the hit or miss being the denouement, as opposed to having the process interrupted by adding your to-hit bonus.

That said, addition is the easier than subtraction, and ascending AC is more intuitive than descending AC (because our brains tend to assume that higher numbers are better.) For these reasons, in my ideal version of D&D, AC (and DCs) would ascend with difficulty, the DM would be obligated to tell the player their target number (be it a monster’s AC or a task’s DC), and modifiers would lower the target number rather than adding to the result of the d20 roll.

In short, when you described an action, the DM would tell you what number you needed to roll to succeed, you would reduce that number by your modifier (or increase it if you had a “penalty”), and roll to see if you meet or exceed the target.
 
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I liked THAC0 back then. Approaching AC 0 was something that felt good.
But since we didn't use Tables and instead always calculated in our head (Roll, add bonuses, then add enemy AC) , ascending AC made it easier for the DM since players could do their math themselves easier.

The only thing, because of the slightly more complicated calculation, enemy AC was not as easily deducted.
 

Retreater

Legend
I've played several OSR games recently using descending AC (and started that way myself in AD&D). Personally, the only reasons I can see to use it are a) nostalgia and/or b) a GM wanting to avoid the work to convert an old adventure and putting the effort on their players.
If you're playing a character with an ability score bonus or a magic weapon, you're already adding to a d20 roll. Why add an extra step to compute what you've done?
How such a convoluted system originated in the first place is a mystery to me.
 

Saelorn

Hero
Given preference, I'll go with ascending AC, but either way is fine.

All I ask is that you pick one and stick to it. The worst possible choice is to not pick a side, and instead write every single AC in the book using some bizarre hybrid format.
 

Horwath

Hero
Let's just say that THAC0 was maybe a good idea when it came out, as they didn't have any other.
And when they decided to put ascending AC and ascending attack bonus, we can now have 20/20 hindsight and say that THAC0 was one of the dumbest ideas ever.
 

Zardnaar

Legend
I've played several OSR games recently using descending AC (and started that way myself in AD&D). Personally, the only reasons I can see to use it are a) nostalgia and/or b) a GM wanting to avoid the work to convert an old adventure and putting the effort on their players.
If you're playing a character with an ability score bonus or a magic weapon, you're already adding to a d20 roll. Why add an extra step to compute what you've done?
How such a convoluted system originated in the first place is a mystery to me.
I think it had something to do with naval class rating the ships.
 

ccs

40th lv DM
Let's just say that THAC0 was maybe a good idea when it came out, as they didn't have any other.
And when they decided to put ascending AC and ascending attack bonus, we can now have 20/20 hindsight and say that THAC0 was one of the dumbest ideas ever.
Hardly one of the dumbest ideas ever (not even in D&D). It was just an artifact of the games miniature wargaming origins. Descending wasn't even the only option in the beginning, just likely that no one in OD&D-1e days even thought to flip it to ascending. Because the creators were building off what they were already used to & the rest of us just took the rules at face value & got on with the game.
2e was specifically made to be backwards compatible so descending was intentionally kept. Though if they'd just kept the "To Hit" charts & not tried to be all slick & using the THAC0 acronym 30 years of commentary could've been avoided.....
3e? Flipping the AC chart to ascending wasn't exactly a stroke of genius.
 


Lanefan

Victoria Rules
Descending AC yes.

THAC0 no.

They are not the same - one can nicely have and use descending AC while never once touching a THAC0 table or mechanic. For me THAC0 just adds an extra and unneeded step to the arithmetic.
 

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