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.?
I don't think of bitcoin as a form of gambling. Before I invest in bitcoin, I will estimate the future price changes of bitcoins and decide whether to invest them. And gambling depends on luck, and it is riskier.