As other already said, if you directly buy a package of something whatever it is, the law says that you have to know the chance to receive the price.
SG (and assume many others) escape from this obligation because you don’t buy directly the package, but instead you buy the gems (and you exactly know what you receive before hand).
Then it’s up to you how you use it, no obligation from the seller after that.
Now, i know that some games use a similar method of purchase but have choose to reveal the exactly odds of their “slot machines”, while surely others may keep them secret exactly as SG does.
While i can respect this decision, i can’t help to ask myself why.
And there’s only an answer that pop up in my mind: there’s something that we better not know.
So nothing that we will be happy for, i assume.
