Let da and db be the results in both d6 dice, the result for the d36 would be 6(da - 1) + db. This gives an equal chance of getting any number between 1 and 36, both included, eg da = 5; db = 5; gives d36 = 29 (which is prime).
It’s just using the result of the dice roll as digits to compose a number in a base 6 positional numeral system.
Maybe it’s not obvious because the formula above is already reduced. Digits in base six can only be 0-5, that’s why there’s a -1 in 6(da -1). Two digits would give us a result between 0-35, that’s why there’s no -1 subtracted from db, I already added 1 to make the range 1-36.
You could use two different dice as well, like a d8 and a d6 to make a d48. Or three or more dice with the same number of faces, eg 3 d6 to make a d216 (they have to be distinguishable, in color, size, style…). For more than two different dice the math would get too messy to be practical, I reckon.
Let da and db be the results in both d6 dice, the result for the d36 would be 6(da - 1) + db. This gives an equal chance of getting any number between 1 and 36, both included, eg da = 5; db = 5; gives d36 = 29 (which is prime).
Very cool, TIL! Is there a name for this mathematical strategy? Both search and AI are failing me
It’s just using the result of the dice roll as digits to compose a number in a base 6 positional numeral system.
Maybe it’s not obvious because the formula above is already reduced. Digits in base six can only be 0-5, that’s why there’s a
-1in6(da -1). Two digits would give us a result between 0-35, that’s why there’s no-1subtracted from db, I already added 1 to make the range 1-36.You could use two different dice as well, like a d8 and a d6 to make a d48. Or three or more dice with the same number of faces, eg 3 d6 to make a d216 (they have to be distinguishable, in color, size, style…). For more than two different dice the math would get too messy to be practical, I reckon.