The power of hindsight.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.
Heh. I can't see what you're responding to, but no.No that superiority was just inherent. D&D just appealed to that inherently superior set of people. So correlation not causation.
I am for descending AC if it were to get renamed something like Physical Vulnerability (PV for short?). That stat getting smaller and being better would make a lot more sense, AND I could then get that sweet sweet D20 crescendo/upset you speak of!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
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.
What if it were reframed to reduce Physical Vulnerability (PV)? As someone earlier pointed out, all one would need to determine enemy PV would be to ask the Referee what the monster's armor is or what the monster's hide is equivalent to. After that it's a tense roll of the d20. I don't know, maybe descending AC is a lot harder than I imagine. I voted to have either system.I thought THAC0 was a great idea when it came out, since it removed the need for tables (updating all the tables when you levelled up was a real pain). I also find it very easy to use, even though I haven't used it in an actual game for the best part of 2 decades. So maths wise, I don't care one way or the other.
However, I'm in favour of ascending AC because I don't like the idea of magical +1 armour reducing your AC.