Back rooms are the same as dark rooms.  They are generally either standalone clubs or they are attached to an existing bar or club or pub that operates with lights.  When you enter a dark room or back room either as part of a commercial venue or standalone club, the lights are off, there is no lighting.  You fumble your way around until you find something or someone or some object you want to have sex with and then you engage.  You don't know anything about that person, you don't know what they look like.  All you know is what you can feel in the dark. What you can feel in the dark if you saw in the light you might run from.  But because it's dark you have no idea who or what is in front of you.  Generally by the time you've entered a back room or a dark room, you're disinhibited.  You've taken alcohol, drugs, recreational drugs of some kind or the other, or you just don't care.  And you walk in and literally anyone can have you and you can have anyone.  You can be rejected but there will always be someone there who will make space for you.  And because these aren't monitored, no one knows what's going on with them; no one has studied what happens in back rooms to the extent of saying making definitive statements as to what takes place.  When I managed Heaven at the same time there was a London's first back room opened in Lester Square.  It was a club called Adams which was on the basement floor below one of the cinemas in Lester Square.  Adams was notorious for its back room.  And because I managed Heaven I knew the manager of Adams.  He told me every morning (it was a late night club) they couldn't clean the back room because it was so full of shit and God knows what, it had to be hosed down and sucked up with industrial wet vacuum cleaners because there was so much fecal debris in those back rooms.  So people having sex in back rooms, you may as well shove your dick into a blocked toilet because that's what's happening.  When you can't see, your eyes are a very visual component of your sexual equipment because you need to make a judgment that yes I want to have sex with this person, he's safe, he's attractive, he's clean.  But if you can't see you can't make that judgment and that's the gateway into whether you want to have sex with that person.  But if you haven't got that gateway access, you're in danger.  Back rooms and dark rooms I would say are the major gateway into HIV infection these days.