I've been trying to decide how i want to handle "fudge dice". Mechanically it's kind of ugly in this scenario.
It's basically 1d81 with 9 scales of use. Given that we are going to be using online random number generators for our dice... We can actually roll an 81 sided die...but then that involves looking at a chart, and even then I really don't like the probability distribution. It's a little two ugly.
Same probability distribution i don't like but we could roll the 4d6 and look at what numbers are rolled and then make and 5/6s pluses, and any 1/2s minuses, but that's kind of ugly.
Here's what I purpose... I think the probability distribution is a little better and a little more epic.
Roll 3d6
Rolled: 3-4| 5 | 6-7 | 8-9 | 10-11 | 12-13 | 14-15 | 16 | 17-18
Result: -4 |-3 | -2 | -1 | +0 | +1 | +2 | +3 | +4
It increases your odds of rolling a +4 or a -1 by a full half a percent! (semi-sarcasm), while it is weighted a bit more heavily toward the middle, the probabilities are within a percent or two either way for each category. And I was serious about the extra .5% for the big pluses and the big minuses.
But we can just as easily do the 4d6 thing as well.
It's up to you. Everyone gets a vote.