[quote=@Mae]
I'd be [i]really[/i] curious to see how much % chance switching from a D6 to a D8 actually affects your chances though. Now you've got me looking up the system...
[/quote]

The chance of landing on any side of an 8-sided dice is 12.5%. Therefor, you have a 25% chance of rolling something that is unattainable on a 6-sided dice, and a 37.5% chance to at least get something equal to the highest number on a 6. Compare that to a 0% or 16%-ish chance respectively. Or if you prefer a non % based representation of this in the real world, let's do number of times out of 24 since that's a number both 6 and 8 go into. If you rolled both dice 24 times, the d6 would give you a 6 only 4 times, where the d8 would give you a 6 or greater an astounding 9 times.

Another fun test, let's pretend you have "perfectly normal" luck and you'll always roll each side of the dice the same number of times. in 24 rolls, You'd roll every side of the d6 4 times which is (1 + 2 + 3 + 4 + 5 + 6) X 4 = 84. Meanwhile, with the 8 you would get each side 3 times for a total of (1 + 2 + 3 + 4 + 5 + 6 + 7 + 8) X 3 = 108