I think that's a cynical view on their reasoning -- if anything prisoners not being bored is in their best interest in terms of keeping guards safe. My guess i

I think that's a cynical view on their reasoning -- if anything prisoners not being bored is in their best interest in terms of keeping guards safe. My guess is that a lot of problems stem from gambling debts -- you can allow cards and stem gambling a bit by preventing chips from being introduced (in whatever form). With DnD tracking across the game is important so it's not as easy to prevent a ledger from forming.