Hi,
here are the rules that I know about
1-every one over 3 who dines at a buffet or family style restaurant will be charged on the dining plan
2-children need to choose from the children's menu if there is one. You could pay OOP if a child is not eating much at a meal --ie. fell asleep.
3- you can share a meal with someone on the dining plan. we did this at Brown Derby. DH had the cob salad that was huge and I had a steak and veggies. We asked first. They said no problem and even let us each order a drink ( I think that they were being nice about the drink).