I recently purchased the Black Hack after seeing a lot about it. While I'm not as enamored by it as everyone else seems to be, there are some points I like. I thought the way it does usage dice is cool and reminds me of my weapon degradation rules. The way they do rolling stats is interesting, as it takes into account if someone rolls a very high stat (15+). Reading it, I was inspired to do something similar, but for rolling low rolls.
|Sorry about your damn luck!|
Roll 3d6 down the line as normal. Like in the Black Hack, if you get a 15 or higher, your next roll is made on a 2d6+2. If you roll a 6 or below, your next roll is made on a 2d6+5, then as normal afterwards.
This method helps to make it less likely that a player will have multiple stats below 6 and really helps to give them a chance to get a greater stat to make up for the low stat. So if you roll a bad STR, you at least have the chance of getting maybe a higher DEX.
Looking at the probability curves of 3d6 and 2d6+2, you'll see that the average of 2d6+2 is 1.5 lower than the average of 3d6. It allows for the average to come out lower to make up for the fact that you rolled really high before. Furthermore, 2d6+2 completely cuts out any result of 15+, since you already rolled that before. I decided to apply these same principles for rolling a higher amount. 2d6+5 has an average roll of 12, which is 1.5 over the average of 3d6. It also completely removes the results of 6 and below, making it easier to land something higher than a 10. Overall, I think this does what the original rule does. It helps to make an interesting character with some clear strengths and weaknesses and normalizes the rolls a little bit. Both of these help to make a character that's not a superhuman powerhouse nor a chump.