Gambling in a fantasy world with divination magic

[Stormonu]

I think the answer depends in part on whether there's a deity of Luck in the setting to whom those running gambling establishments could appeal...

The god of Luck and the god of Fate walk into the Devil's casino.

"Let us see who can win the most," Luck says to Fate.

"But no one wins in the Devils casino," chides Fate.

"Ah, but perhaps between us two, our luck shall allow us to avoid such a fate," smiles Luck.

 

[Hand of Evil]

This is why you have gods; such as the god of chance and games, Las Vegas and why luck is a lady, they keep this stuff from happening.