1d6 initially, even = 1-10 for the next roll, odd = 11=20
Next roll 1d6 even = 1d5 for the last roll odd = 6-10
Last roll is normal but 6's are re-rolled.
So first roll determines if the result will be between 1-10 or 11-20
Second roll determines if the result will either be A: 1-5 or 6-10 or B: 11-15 or 16-20 (based on the first roll)
Last roll gives the final result within the set parameters.
Every number should be equally as likely with this setup. It's a 50/50 chance for the first roll, the same for the second, and the third roll is a 20% chance for each possibility.
IF even is low and odd is high you need to:
Roll even/even/1 to get a 1
to get a 20 you need to roll odd/odd/5
To roll a 10 you need to roll even/odd/5
To roll a 14 you need to roll odd/even/4
Every outcome is just as likely as every other.
By the logic everyone else is using in the thread, this is different than rolling a d20 because there are 180 different results ---