Yes, in my religion gambling is a sin. Because when you win, you can become addicted to gambling. And you'll do anything to get money to gamble when you're broke. Such as stealing, robbing and others. It was very dangerous, so my religion forbids gambling. There are many more reasons why my religion forbids gambling.
in some religion playing gambling is a sin, there is no doubt about this as in Islam gambling is a sin and in Islamic countries if some one is caught red handed playing gambling will be punish for that, and will be put in jail, but in some countries it is only banned for under 18 years of age, while the above can play gambling legally, in these countries there are proper casinos where people visit to play gambling and putting effort to make money.
Exactly, I also know about it, many Islamic countries are not allow to play gambling, because in their religion gambling is a sin, and because of it, they punished the people who play it, But instead of it, many Islamic people do it, and also they depend on gambling on earning wise, But in other countries it is legal, but not for kids, and Personally, i think it is right, because gambling is not a kinds game.