Gambling can exist everywhere; it’s part of human desire for challenges and the yearning to satisfy oneself. Even if the prison guard restricts and monitors the prison, there’s a possibility that inmates can gamble.
If a gambler entered a prison, he would find a way to gamble. There’s a saying: "If there's a will, there's a way."
There were reports here in our country that VIP prisoners can bribe the guards so they can operate inside the prison.
It’s very rampant in the third world; gambling will find its way everywhere, even in a harsh environment.