No gambling is not restricted to some individuals or classes of people, anyone is allowed to gamble. Of course there are some age related restrictions but other than that I don't think there's any kind of restriction. If a country's law doesn't allow gambling and the country takes strict action against casinos then in such places it might be not possible to gamble, but many people even from such countries use VPNs to gamble on online casino sites. No stratification at all when it comes to gambling, like I said above everyone is allowed to gamble.