it determines a random value of bounty you will receive
take a normal dice for example (lets say the number on each side represents gold)
roll your dice, and you'll get a number between 1 and 6
if you roll 2 dice, you will get anything between 2 and 12 (cant go below two since minimum value for each dice is 1)
the greater the number of dice, the greater the lowest possible random number you get
the greater the number of sides, the greater the highest possible random number you get.
if you have 1 dice, 100 sides, you could get anything between 1 and 100
I do know this - xenforo dropped the ball by not keeping the vbulletin reputation comments as a feature. The loss of the Reputation comments data when we switched to Xenforo really was the death knell for the site when it came to all the users that left. I know I missed it so much and I got way less interested in the site when that feature was gone and I run the site.