And also when I was growing up watching movies locally, there will always this plot twist that there is a illegal gambling den and it will be raided by the hero of the movie and then those running it says it is being protected by high officials of the government.
And so have you heard of it like in your country?
I also dig one story about it here:
Eugene Trincher ran a high-stakes illegal poker game in New York City from 2010 through April 2013. At these games, the pots frequently reached tens of thousands of dollars or more. The operators of these poker games, including Eugene Trincher, collected percentages of the pots known as "rakes." Each of the poker games employed at least five or more people to assist with the operation of the poker games, payments of debts, and collection of debts.
Or have you played in this kind of underground gambling den before?
Underground gambling only tends to exist in countries where it is illegal or heavily regulated. Keeping in mind that it's usually illegal, you're only going to get introduced via friends who trust you and generally you'll have to put up a fair amount of money to enter. Besides that, these places will be very discreet and have security vetting you before you're able to get anywhere near the action. The more upscale places will be very professionally organised and have the higher rollers in there, but are invite only. People just love betting and will find a way to do it, the only difficult bit is making sure nobody leaks any information about the operation - this usually happens when someone is bargaining for a deal on some other crime they might have committed.