In traditional slots you pay a coin, and if a certain sequence comes up, you get some winnings. I think everyone will agree that's a form of gambling.
In bitcoin, to create coins, you pay some electricity, and if a sequence of 0's comes up, you win some bitcoins.
Is this aspect a form of gambling?
And if so, is that illegal in the U.S.?
If we consider it from investing point of view then we can say it is a type of gambling because you are betting your money without knowing the outcomes and you can loss or win.