Hardwork for what? Hacking the system? I guess it is just applicable to online sites or other electronic based games which includes machines or program. Card game can somehow be predicted knowing it has a limited numbers existed. But games like roulete and other lucky games cannot be hacked even you work hard for it so it doesnt makes sense.
I don't know anyone can hack the gambling sites or not?
But if they can then they can be one of the richest people in this wrold so I believe any kind of online gambling sites cannot be hackable.
This depends on the gambling site we are talking about.
There are a lot of gambling sites online and some of them are trusted by a lot of gamblers all over the world. I know you know there are a lot of times that gambling sites and exchange are hacked and that means they can be though not all of them. I am saying this depends since there are times that gambling sites and this exchanges are vulnerable and hackers can find a way or maybe a small hole to get into to hack their sites. That is the reason a lot of sites are being careful to what they are doing especially this gambling sites and exchanges.