I guess I can understand the dice ban (sort of?) but the fact that some prisons have apparently have banned games like D&D altogether is bizarre to me. It seems like a healthy, relatively peaceful way to pass time and do something creative. I can't see it having a negative effect that other prison activities don't already make possible.
I was a gamer in my teens. One younger member of the group was probably being given a hard time by his religious family for being a gamer. He was often absent from gaming sessions.
The weekends he was absent consistently included stories like a drunken car wreck, and now he has a broken leg, or a wild party where some gal says he is the daddy and he has no idea if he even slept with her.
I never could fathom why his family didn't just tell him to go gaming every weekend. We fed him free food, used no drugs or alcohol and drove him home safe.
But we were Satan worshippers, I guess, because we gamed. ¯\_(ツ)_/¯