When it comes to purely luck based gamble, there are no use of hard work. Yeah there are strategies but that again are just luck and probability.
But when it comes to analysis based gamble like say sports betting, a hard work doing research and analysis would yield you better result with larger probability of your success.
On another hand hard work counts when you play games like chess, absolutely strategy based one. Poker is also combination of luck and strategy, sometimes you blef and win with bad cards but sometimes different thing happens.