When the game first launched you could create a 'friends only' room but they neglected to have a way to invite your friend. Your friend could search for rooms with only their 'friends' in it but there was a bug that prevented your friend from seeing your room! lol I had to create a public room and send my friend the room number and while he was searching for it I'd have to constantly kick people until he showed up. They just patched the issue so if you create a friend only room your other friends can search for it and find you much easier now. I do wish there was some sort of in game invite system though.