Gambling is illegal in Iran, but there are luxurious underground casinos fully equipped for card games. Interestingly, many famous athletes, artists, and even politicians—who publicly condemn gambling—can often be seen in these underground venues.
Without those big names being involved or having something to do with that place, it will be hard for an ordinary citizen without any government backup to pull off something like that, knowing the implications if they are caught, and if somehow they get exposed and the officials who are not part of the deal for getting that underground gambling running happen to notice, the place will be shut down, and it will be hard for the owner of the place to be tracked down.
Most of these underground casinos are owned by billionaires and prestigious men, and these men has all it takes to get government approval (secretly) to operate without any form of interference by the government or the police. Even if they ever get bursted, they'll still know how to get themselves out and continue their business without disturbance.