Has anybody else noticed that glitches have some odd probablities associated with them? Used house rules to fix this?

Below is the output from a program I wrote to show (roughly) the chances of glitching for various pools and varieties of glitch; note that in all cases these are normal glitches, not critical. This data is based on 100000 rolls; the pools used for each column are the same, and smaller pools are sub-sets of larger pools, so you can at least compare "apples to apples", even if the specific values are off a bit due to sample error.

The "glitch" column is for the basic glitch rule. Worth noting is the chances for glitching with 4 dice is HIGHER than that for glitching with 3, 6 is higher than for 5, etc. Its in fact almost twice as likely.

The "grem1" column shows the chances of glitching if its a test using the Gremlins Quality, rating 1. Again, the chances are higher for even number dice pool sizes than for the next pool size down- again, almost double.

The "rush" column shows the chances of glitching if its a test using the rushing a job rule (1's and 2's count towards glitches). Again, there's the same issue, and its pretty noticable, though the jumps upwards are not quite as severe.

The house rule I came up with to address this is something I call the "hold one" rule. Basically, one of the dice in your pool (physically it would be an odd colored or otherwise distinctive die unlike any of the other dice) is "held back" for glitch purposes, and only if the roll is a glitch both with and without the "hold back" die is it really a glitch.

The "HO" columns show the same role types as the previous 3, using the "hold one" rule. The basic effect is obvious from these charts- the chance of a glitch with an even sized dice pool is the same as that of the next smaller odd sized pool. This removes some of the oddities from glitching, but also decreases chances of glitches over-all. Are glitches a big factor in play? There's ways to bump up the chances a bit so the curve matches the basic glitch curve but is (much) smother (adding an extra die that contributes if it comes up a 1 works well), but is the added complexity worth it?

I'm also considereing replacing the gremlins rule with one that has characters using something like the rushed job rule, because I like the fact that large pools can still glitch, and small ones don't do so automatically.

pool glitch grem1 rush HOglitch HOgrem1 HOrush

2 0.306 1.000 0.555 0.167 1.000 0.332

3 0.074 0.423 0.259 0.074 0.423 0.259

4 0.132 0.518 0.408 0.074 0.423 0.259

5 0.035 0.196 0.209 0.035 0.196 0.209

6 0.061 0.261 0.318 0.035 0.196 0.209

7 0.018 0.095 0.172 0.018 0.095 0.172

8 0.030 0.134 0.258 0.018 0.095 0.172

9 0.009 0.048 0.144 0.009 0.048 0.144

10 0.015 0.070 0.213 0.009 0.048 0.144

11 0.005 0.025 0.121 0.005 0.025 0.121

12 0.008 0.037 0.177 0.005 0.025 0.121