I think people do wear them, but I really didn't notice (too busy studying the menu!!). My teen boys wear docker type pants and button down shirts (print or "hawaiian" type) on casual nights. Many teen boys wear this "uniform" until after dinner, when they dash to their cabin to change back into their shorts. I don't think it's "against" the rules. to wear jeans........the rules never say "no jeans", but I pay for the cruise, so it's against the rules in my family. By the way, my kids don't mind and it's nice seeing them in something other than baggy jeans for a change.