How old you have to be to play online depends on the country you live in. In most of Canada and of most of Europe, you need to be at least 18 years old to gamble. In the United States, the age restriction for gambling depends on the state, but in most cases it will be 18 or 21. In some states, including British Columbia, New Brunswick, Ontario and Nova Scotia for example, the minimum age is 19. In addition, there are also states that do not allow gambling, including Hawaii and Utah. If you are not sure if you can gamble, check first before joining an online casino. If you gamble when it is not allowed, your winnings will be forfeited.