Your dormitory is really just like a group or club. There is an admin, and people can join in order to socialize with each other. Basically, it's just your room at Hogwarts.

Personally, I think your dorm groups are the best places to role-play. There are fewer people, and the chats are private to everyone other than your own personal dorm group. I'm honestly not a fan of role-play, I just write my own stories, but to each their own, right?

That's it on dorms. I don't really think there is much else to do in those chat groups except talk, and such, but if you guys can create such a website like this, them I'm sure you can come up with some other things to do in the dormitories!