I don't think it will illegal.
It depends on which country you are in. It is a case to case basis. 1 talked to one of the members here in bitcointalk.org and he says that Bitcoin is fine in his Southeast Asian Country but if they found out that you're Bitcoin came from winnings in gambling they will deactivate your soft wallet. They say it is part money laundering.
This. Online gambling is legal in the UK, and in many parts of the world. In the USA it's trickier - they don't like online gambling because it breaks the monopolies of the state owned gambling boats on the Mississippi and in the Native American reservations.
When bitcoin was new, lots of bitcoin gambling sites sprung up precisely because it is easier for Americans to gamble with bitcoin. (In the USA, VISA and Mastercard block spending on gambling sites, so if you want to gamble online bitcoin, and now alts, are your ownly choice).