Multi-directional stats isn't a very good name, I know, but here's an idea I had earlier today (I apologize if someone has already mentioned this before).
Awhile ago I realized that +1 is the "middle" of the stat range. At +1, you have more chance of getting a weak hit than anything else (16/36) and you have exactly the same chance of getting a miss or a strong hit (10/36 each). If you compare =0 to +2, and compare -1 to +3, they're also symmetrical, but inverted (e.g. +3 has the same odds of getting a strong hit that -1 has of getting a miss, etc.).
So that got me thinking that if you had two stats that were on a continuum where increasing one stat lowered the other, then you could use a single stat to represent both. The moves that reflect one "side" of the stat would be standard (i.e. 6- is a miss, 7-9 is a weak hit, and 10+ is a strong hit) and the moves that reflect the opposed side of the stat would be inverted (i.e. 6- is effectively a strong hit, 7-9 is still a weak hit and 10+ is a miss).
Then you could have that stat slide up and down to reflect where you are on the continuum. I have a couple ideas for how to use this, but I was wondering if anyone's already done this, and if so how it worked. I'm also wondering if I'm missing any obvious problems with doing something like that.
-John B.