Last week I investigated the probabilities associated with spending a fate point to invoke an aspect in FATE. The version we looked at was using FATE dice, which produce results from -4 to +4.
There is a common variant to using 4dF, which is to use d6-d6, which produce results from -5 to +5. The distribution of this dice variant looks like this:
So the question is, should we spend our Fate Points differently if we are using the alternate dice variant?
We can use this cumulative probability graph to help us decide:
Just like with 4dF, there is a threshold when you roll -2. At this point, spending a fate point will bring your result to 0; however, you would have a 42% chance of rolling a result greater than 0, and a 42% chance of rolling a result less than 0.
So if you roll a -2, and a 0 just won’t do, you’re better off with a re-roll. If you don’t feel like gambling, and a 0 is good enough, keep it.
For every result above -2, you are better off keeping the +2. For every result less than -2, you are better off re-rolling.