I was thinking about the ability to make second floors etc. with people not seeing and interacting with each other on the separate floors. I heard that it was impossible, but what if you used the see invisible roof trick combined with an elevation system such as ebonyshadows? Some other things would need to be added to such a system, such as:
-The mobs invisibility rating changing when entering the higher floor(s) so that the people on the lower floors couldn't see them.
-Objects dropped on higher floors are automatically given invisibility appropriate to the floor
-Each floor would have its own invisibility level, top floor the highest then down from there
-Each floor would need its own set of objects/turfs appropriate to its levels variables
I realize that making the actual map would be hard since you couldn't change one level once the others are done, but its just an idea. However I wouldn't even know where to start coding, so if any ambitious people are out there with nothing to do here is something for you.