In my country gambling is considered unlawful act. Meaning that gambling is wrong. And right, gambling has taken up time, thoughts and money we have. There's more to do and certainly more benefits than gambling.
We take it simple, gambling is wrong from the beginning, and whatever we do, even though we play gambling correctly and according to the rules, we keep doing the wrong thing, and doing the wrong thing is wrong. And more wrong if we fall deeper until addicted.
I don't think gambling is wrong, it's some sort of entertainment.
Nothing is wrong in testing your luck and trying to win something as long as you are playing with money which you can really afford to lose. Gambling is wrong when it starts to effect on your life and on life of people which are around you, for example your closest family.