Hi,

So I am reading through the OSE Rules time and I am looking At AC.

The decending AC used THACO and a chart which seems a bit complicated
While Ascending is just beating a  targets AC.

Which version of A.C. Do you suggest for an OSE game?

Ascending.  It's just easier. 

That being said, the easiest way to think of descending AC is the rule of 19.  The target number is derived from two numbers that add up to 19.  One is you Armor Class.  The other is the target number.  Together, they add up to 19.  So an decending/old school AC of 5 means your target number to hit is 14. 

5+?=19 which is obviously 5+14=19.

Old school descending armor class was always a bit wonky.  It all came about because of British sailing ship rating system.  Huge warships like 100+ gun armed HMS Victory are called a 1st rate.  90+ gun ships are 2nd rate.  74 gun ships like France's Belona class were 3rd rate, etc until you get to little corvettes with 12 or so guns that are 6th rate.  So now everyone associates the best as 1st rate.  It HIGHLY unlikely most people even know why something 1st rate is the best.  It just is for some reason, and old British Navy is probably the last thing they would guess.  And Gygax did too.  The best armor was AC-1. 2nd best is AC-2.   So he went with that, and efficiency in rules writing had to come later. 

So we've moved on since then and just tell you the target number is the AC to keep it simple. 

Ascending is not only easier, it also means you can use stuff from other OSR games with less conversion.

I prefer ascending. I know that descending is the "way it was" but I find that continuing to do something one way when I find something better is just absurd. I had a house-rule ascending rule in place decades ago where I used an "armor rating" and the to-hit was 10+AR. The official 3E one is a lot better, but we got to the same place.

I prefer descending AC using 10 as unarmoured.

Ascending AC may in fact be easier for newbies and the mathematically challenged, but it still looks "off" to me, having started with B/X.  So even in games with both options, I'll always choose descending AC.  Descending AC is not difficult to understand nor is THACO the equivalent of quantum physics, as some seem to think.  But nowadays check out clerks can't calculate change from $1 so things like THACO are considered unfathomable.

Integrate the weapon verses armour table with the attack table so there's no way to play the game without it.  Tie damage die to weapon size and only allow attribute bonuses to the attack roll. tiny 1d4, small 1d6, medium 1d8, large 1d10, huge 1d12.  Replace hit dice with fixed amount of zero level hit points by size thus 1 hp for tiny, 2 for small, 4 for medium, 8 for large, and 16 for huge.  All player characters get their size hp in addition to their first level hp.

why?

Ascending.

"In theory there is no difference between theory and practice, while in practice there is."

In theory, there is no real mathematical difference between ascending/descending, if you're using a linear chart; the AD&D one is NOT linear at times, B/X is for the most part. In theory, I prefer descending AC because that's what all my D&D books use and what I have used forever. In practice, after a couple drinks and getting annoyed having to look up crap on a chart, ascending AC is just easier. Probably why I actually like to play C&C instead of AD&D, even while greatly preferring AD&D as a game. Add HD to d20 for monsters. It doesn't get much simpler than that, and considering all the games I play in and run are super deadly if you're dumb enough to get into combat, we want to get that stuff over with quick.

This is one of those situations where all the discussion and hand-wringing in the world will never overcome the simple fact that until you try it out in a real game, you most likely won't know which is better for you.

Quote from: Gegilles on April 02, 2023, 10:11:04 PM
I prefer descending AC using 10 as unarmoured.

If I may ask, why?  Not challenging you, I am just curious.

Quote from: Brad on April 03, 2023, 08:57:57 AM
This is one of those situations where all the discussion and hand-wringing in the world will never overcome the simple fact that until you try it out in a real game, you most likely won't know which is better for you.

So you think that I should try using descending and see how it works and if it doesn't work well or is a bit too overcomplicated for the group then switch to accending?

Quote from: GhostNinja on April 03, 2023, 09:42:59 AM
So you think that I should try using descending and see how it works and if it doesn't work well or is a bit too overcomplicated for the group then switch to accending?

I think you should probably just use ascending AC since you seem to have no real attachment to descending. There's no legitimate reason to pick one over the other except familiarity, but ascending tends to be easier to explain to new players and requires no chart.

Quote from: Brad on April 03, 2023, 10:11:48 AM
I think you should probably just use ascending AC since you seem to have no real attachment to descending. There's no legitimate reason to pick one over the other except familiarity, but ascending tends to be easier to explain to new players and requires no chart.

Does it mess when anything in OSE or does it cause problems with weapons or armor using ascending AC?

Totally agree.

But it isn't that difficult either.

Quote from: Persimmon on April 03, 2023, 12:32:27 AM
Ascending AC may in fact be easier for newbies and the mathematically challenged, but it still looks "off" to me, having started with B/X.  So even in games with both options, I'll always choose descending AC.  Descending AC is not difficult to understand nor is THACO the equivalent of quantum physics, as some seem to think.  But nowadays check out clerks can't calculate change from $1 so things like THACO are considered unfathomable.

Quote from: Gegilles on April 02, 2023, 10:11:04 PM
I prefer descending AC using 10 as unarmoured.

ditto

I would guess that the farther back people started playing, the more likely they prefer descending AC vs ascending.