Many things are prohibited in prison, but almost all of these prohibitions cannot be controlled by the prison guards, will be very easy for prisoners to do it because just imagine class of narcotics can be played or traded by some prisoners who have certain connections from insiders and prison is not as imagined by some people who think it is like being locked up continuously in an iron cell. There is still a freedom and it should be noted that not all people who become prisoners are poor, many rich people in it so that anything can be done with money, even bribing officers so they can get more freedom in prison. Agree with gambling is always present everywhere and gambling in prison is not surprising.