have you ever been to prison? it is a tough life in there. no matter what you did or whether you were wrongly accused for something, prison is not for everyone. it is obviously lonely as you gets separated away from your family. it can get boring, not being able to do what you want.
but gambling, even tho is prohibited, is often what entertains most prisoners. there is no actual money in prison so they often exchange in other forms of currencies like food or smuggled items. even their way of gambling is smuggled. cards, dice and even information from the outside are all smuggled.
the reason why gambling is prohibited tho is because it might escalate into fights if someone for example loses and doesn't pay their debts
just shows how gambling will always exist anywhere
legally gambling is not allowed in prison, but for sure there are card games, etc, but if you are talking about betting on what people to in the outside that's not gonna happen there, maybe they will ask their love-ones to bet on their behalf outside to do gambling, and yes they might bet food or cigar, if there are basketball court in the prison they do bet for sure who is going to win.