I need to get my head around how this works as this what I am thinking so far.
There are 13 abilities possible abilities to roll. Most brands one has a 5x chance the other a 0.5x chance so think of it as 26 balls in a bag, two for each ability (13 different colours...ugh). We take away one to represent the 0.5x chance. There are 25 balls in the bag now. Now we add another 8 to represent the 5x chance. So the bag now has 33 balls 10 of which are one colour so the so those three abilities the same you sometimes see are a (assuming they are the increased chance) 2.7% chance? ( [10/33]^3)
It sounds kind of right but maybe I've misinterpreted something or the game handles the numbers oddly.
Here are the full #s
https://docs.google.com/spreadsheets/d/1mE97vf8FxdfvR6pt7tFvYXkYGSZGg4AsrTI_2veUlbs/edit?usp=sharing