Fudge dice and modifiers.

I’m a big fan of roleplaying in general. Too bad I’ve never actually played, which is a story for a day when I feel more sorry for myself. In any case, one of my favourite dice rolling systems is Fudge.
Fudge rolls are relatively simple: you roll a set of dice, add or remove modifiers, and then compare the result to a difficulty threshold or another roll. The twist is that Fudge uses dice that have minuses, zeroes and plus: mathematically, a Fudge die is a d3 with -1, 0, and +1, though physical Fudge dice are six-siders with two of each. One die results in a result from -1 to +1: four dice -4 to +4, with 0 centered on the bellcurve (AnyDice calculator; click on “Graph”). In practice this results in a more intuitive system than using simple numbered dice; an “average” is no more an arbitrary number somewhere in the middle of a 3d6 distribution, and you can easily expand into further reaches as you wish, creating something that is theoretically quite scaleable even regarding small numbers.
For the Game Project, I’ve been thinking of using the Fudge system for internal rolls. The only downside with Fudge rolls comes to the fore here: the granularity of modifiers is very high. A +1 or -1 can make a huge difference. There are several systems on the net that remove some of this granularity, and it’s been on my mind, too. Here is my solution:
The simple version of my Fudge modifier system is to use a numbered N-sided die, together with an ordinary 4dF roll. Modifiers are summed together into a single number: “1 modifier +2 modifier -1 = 2”. Roll the modifier die: if you roll equal to or below the target number, add a bonus +1 (or minus -1) to your roll. If your bonuses equal or exceed the number of sides on your bonus die, “carry” that into a set bonus or minus modifier. So: if you use a d6 as a modifier die, and you get a “+6” modifier to your roll, transform your “small” bonuses into a set +1 on your result. If you have “+12”, that’s a +2. ( Check out more AnyDice graphs )
You can adjust the granularity of the bonus system by changing the size of the modifier die: everything from d2 to d100, and beyond if you want. On a computer, the possibilities are endless. For the game, I’ve decided to use the inbuilt random functions: specifically, the basic floating point random function, that gives you a random result between 0.0 and 1.0. It becomes a simple thing to change the system so that all modifiers can be expressed as a single floating point number: +2.444444444 would be completely valid, and represents a +2 plus a 44.44444% chance of getting a bonus. The mathematics become simple: you can simply subtract arbitrary floating point numbers, and you can have arbitrary precision when giving or taking away modifiers. -0.0001 is just as valid as +3.0.
The Fudge systems simplicity also means that I can change everything that has a stat into this kind of (signed) floating point number: -2.5555 would be a very poor stat, while anything about +5.0 is legendary in status. You can have a steady flow of change (through experience, and other such events), without introducing further complications other than simple addition and subtraction.