So I tried to post this on another forum, but the forum didn't seem to like me and the message wouldn't post. Of course that means I probably triple posted it or something. Anyway, I spent a bit of time on this today, and I'm happy with what happened. Please feel free to tell me this is already known (and then please show me where to find it and other stuff like it), or tell me that nobody cares and that I should just drown myself in bucket of goat poop. Exact copy of what I tried to post elsewhere: Don't know if anyone cares about this, but I think I've got it. I found an old post that asked about this, but I didn't feel like grave-digging. For reference, this is the older thread. *I removed the link since it goes to a different forum* This formula is ugly, and I'm sure there is a more elegant way to express it, but it works. It doesn't, however, take in to account T/M Aptitude, lighting penalties or obstructions. I have no idea if it works for Throwing, Bow or Firearms. Likely not since range becomes an issue with those skills. However, it does work for melee without obstruction or lighting penalties. 25+20M - AC[.1(M+1)] = T% where M equals your melee rank (0-5), AC equals the targets Armor Class, and T equals your To Hit value expressed as a whole number. And in actuality, the constant ".1" is actually an irrational number that is roughly .104838. Because of this, using .1 becomes a bit inaccurate once the target's AC increases over 40. But it's close enough. E.g. if you have 3 points in melee and your target's AC is 42, then your chance to hit is roughly 68.2%. 25+20(3) - 42[.1(3+1)] = 68.2 Then again, I'm currently using a mod, and I have no idea if the mod changed the To Hit formula from the vanilla Arcanum version. Anyway, I searched for a long time for an exact formula. Now that I look at it, it's pretty much useless. But whatever. There it is.
No one ever posted any of this data so when I began modding Arcanum I had to run my own tests. I still have the chart I made but haven't put it up yet except for 3 main results in response to an inquiry. A real formula is appreciated because I recall that when I was trying to deduce one myself it was very close to the .1 ac modifier value but weirdly not exact. I think this might have more to do with the fact that the to hit % goes beyond 100% sometimes which makes a kind of axis offset effect in the formula (when you graph the data from a chart of the values), but I can't remember exactly offhand and I never derived it precisely myself back then. I also have data on lighting and everything else I could find that would/wouldn't affect to hit %. Tech aptitude in particular seems to reduce gun weapon to hit % linearly to something extremely low (again based on memory). The sad part of this is the magic points value in the monster files is multiplied by 4, so it's hard to test what's inbetween. As an aside, the perception bonus is extremely strange for ranged weapons, because there's a kind of sweet spot at certain values where having so much perception and being at an exact range is ideal, but going closer can make you miss more. Really bizarre.
Yeah, I had started to play with ranged weapons when I noticed that the number got smaller as I got closer. I realized it was something I didn't want to play with. Thanks for the reply, Leonidus. This is an older forum, and occasionally forums like this that cater to a small niche can be pretty closed off. I'm kind of surprised I got a reply at all. I'm glad the information is in some small way useful.
