I've been designing a small skirmish game for a little while now, and have come upon an interesting dilemma. Without going into too much detail, it's a tabletop miniatures game played on a square grid (think Heroclix minus the clicking and the time commitment). During your turn all of your units can move and attack once in any order. The attacks are written on accompanying cards, and this is where my problem lies
Currently attacks are structured like this:
Slash (Melee, Push-1) 2 - 4 - 5 - 5 - 7 - 10
If the target of this attack has taken damage this turn, roll +1
In this scenario, the numbers above the description would correspond to the roll of a d6. This way I could weight attacks by character, not just with the bell-curve of a pair of d6's plus a set attack value. To me that seems more natural than every character having identical attack curves, just shifted up or down. But I recently came upon the idea of two coin flips. The same attack would look like this:
Slash (Melee, Push-1) 3 - 5 - 10
If the target of this attack has taken damage this turn, 1 auto-head
The four attack values in this case would be double tails - one and one - double heads. The weight on the middle attack would be 50%, so it could be considered the usual value, while the other two are a failure and a critical hit. "Auto-head" means that only one coin is flipped and the other is presumed heads. Anyhow, I'm not sure if this idea is good or just fun to think about. It would certainly be somewhat unique. Attached are some graphics for the "miniatures," which at this stage in testing are just paper dolls. This isn't really relevant to the mechanical issue, but it could be helpful in getting a sense of the game as a whole.
It's funny that you started listing probabilities. I always make excel files with all my probabilities for any game. And you're right, going to a fourth coin starts getting a bit annoying. And really, a third coin just returns you to the d6 system. A 3 coin system of 2-5-6-10 is identical to a d6 system of 2-5-5-6-6-10. This idea has definitely taken hold in my mind, I just worry that it is more gimmicky than useful. This sort of becomes the deeper argument of "is originality its own reward?" Functionally, a d6 is perfect. But will the game be "better" if I take it in a unique direction?