Im pretty certain the people that are really rich will never run out of money by gambling. Just imagine you are rich and famous, and you go to a casino. Im sure the casino will actually pay you money to gamble there because if people see you, it will attract potential customers. Im sure those rich elite famous guys have special deals with casinos..
What if he's just rich and not famous? then he will be in big trouble if he losses all his money just by gambling and nothing is forever in this world even money has a limit even if your the richest man alive!