I own a couple of games based on the FATE system (which is, in turn, based on the FUDGE system), and there are a couple of different approaches for rolling dice that appear in them.
The classic system is 4dF. A dF is a FUDGE die and has six faces representing the numbers -1, 0 and 1 twice over. It is a d3-2.
Starblazer Adventures uses a different approach and rolls d6-d6. This has the advantage that you don’t need to run out and buy dice that are so specialised that your friendly neighourhood gaming store doesn’t sell them.
This morning I decided to invest a few minutes into doing some analysis and comparison of the two systems (no doubt duplicating other people’s work, but entertaining myself in the process).
I generated all possible results that each of the two systems could provide, and converted them into percentages and then charted them.
| Total | 4dF | 4dF % | d6 – d6 | d6 – d6 % |
|---|---|---|---|---|
| -5 | 0 | 0 | 1 | 2.78 |
| -4 | 1 | 1.23 | 2 | 5.56 |
| -3 | 4 | 4.94 | 3 | 8.33 |
| -2 | 10 | 12.35 | 4 | 11.11 |
| -1 | 16 | 19.75 | 5 | 13.89 |
| 0 | 19 | 23.46 | 6 | 16.67 |
| 1 | 16 | 19.75 | 5 | 13.89 |
| 2 | 10 | 12.35 | 4 | 11.11 |
| 3 | 4 | 4.94 | 3 | 8.33 |
| 4 | 1 | 1.23 | 2 | 5.56 |
| 5 | 0 | 0 | 1 | 2.78 |
There isn’t much to choose between the results, although the FUDGE dice give slightly less variance and are more likely to hit closer to zero.