UngeheuerLich
Legend
Ok. So your notation is wrong. The math behind it is close. You are indeed just off by 5%.Were 9/23 =23-9=14/20=70% miss or 30% hit. I could be wrong, math is not my thing
I could easily be off by 5% or so, I always forget which way to apply the hit
It is 23-9=14. So you need 14 to hit.
So you miss on a 13 and lower. So it is 13/20 = 65% miss chance. And thus a 35% hit chance.
Actually math would be easier if you did not have to just reach the target number but to beat it.
This means to hit AC 23 you need a 24 total. Then it would indeed be 23-9=14, so miss on a 14 or lower and only a 30%
If ot worked that way, flipping who rolls would also be easier.
AC 10 vs attack bonus of +0 means a 55% hit chance. Which is unituitive. So to flip it, the defende would have to roll d20+0 against 12+attack bonus for an equal chance.