There are only two ways to regularly earn money gambling in a casino:
1. Poker, where you’re playing against other patrons and not against the casino
2. Cheating
1. Poker, where you’re playing against other patrons and not against the casino
2. Cheating
Apparently Stephen Paddock was wealthy.
Gunman Stephen Paddock was an accountant who played $100-a-hand-poker
...Eric Paddock told CNN on Monday his brother had worked as an accountant and had plenty of money. "He was a wealthy guy playing video poker... on cruises," he said, adding that his brother could afford anything he wanted and played $100-a-hand poker. Authorities say Stephen Paddock, 64, lived within easy driving distance of Las Vegas, had a pilot's license and had legally purchased some guns...