Gambling is indeed just a game, some people believe that gambling is like investing in fast forward, since in investing there is still that we rely sometimes in luck to profit. But generally the risks in trading is quite different from gambling. In trading you can minimize risks because you can execute some strategy that can do this, however in gambling you cannot change the outcome of a dice roll.
Gambling does not only involve dice games. People play poker too. Assuming that you know poker, it can be won by applying some strategies.
However, the difference between gambler and trader is, a trader can learn and enhance his wisdom even from zero, but gamblers need god gifted talent. All games rely on either luck or talent you are born with.