Its 1/6 to roll a 7 with two 6-sided dice. You can get weighted dice that make it more likely to land on a certain number.
Does having one weighted dice change the odds at all? My gut says no but reality is a tricky bitch and I’m convinced im wrong somehow.
Yeah, no doubt different facilities run things differently. Depends on where you are, who governs it and it’s security level. Low security gets more privileges than medium, high, or maximum security. Though for us medium security and lower could have small games, dice, dominoes, etc during rec hours.