It is totally randomized. Each roll is also individual or in other words one roll is not compared with another roll to see if an adjustment needs to be made. Therefore, if you were to roll six 20Ds and got 20,20,20,20,20 then that would be your superior lucky rolls because nothing else determined that other than "Luck".
All Dungeon Masters, I believe a Player on Limited Status cannot make Dice rolls. I will schedule to check the code to find out why but at present Dungeon Masters will need to make rolls for Limited Players in their game.
Although there is already text that indicates that up to 20 fields are available for Dice some Players may still be unaware so I have emphasized it in the Dice Box where it says:
With talking to others I have to really wonder just how random the embedded dice roller is. With a above average of low numbers being rolled compared to high numbers with little to know middle ground it can make one actually wonder how the dice react to be truly randomized?
This was brought up before, you can read the Discussion starting here: Embedded Dice Support - Page 8 of 12. Nothing has been changed since then. Your results will be more 'emotional' because it affects the Characters for whom rolls are made even if on an unlucky streak, however the Embedded Dice is no respecter of the Players so each result is truly random.
It greatly concerns me after reading this thread that allowing people to buy success in Dungeons & Dragons is even being considered by players or moderators. Pay-to-win is not what I signed up for nor what I donated real money to this site for shortly after joining, so I really hope this has not and will not ever be implemented.
If this has been implemented in any way, please let me/us all know, but my impression is that it hasn't been or it would have been announced here.
Just my two cents…
PS I imagine it is not worth the work involved, but the raw data of dice rolls by thread, player, dice type, etc. Etc. Isn't available at all, correct?
Going to run a test as well since I'm here…