Personally, I have occupied what once was called "the study", but with kids demanding their own room, I highly sympathize with people who are cramped for space of their own.
Oh ok, as long as you're allowed at least a room dedicated to it. If no space for a room then at least a "shrine" in a part of a room.
Maybe a Murphy's bed type layout for gaming. Press a button and the wall flops down into a full-fledged game room XD
I'm going to make it so I pull back a certain book in the book case and the whole thing swivels around.
To be frank I'm not "allowed" anything. I don't live under my dads roof and have to follow his rules as long as I do. I'm perfectly free to turn my entire house into a Toys R Us if I want to. And if I had a mental breakdown or developed some mental illness or got brain worms or some other thing that caused me to want to do that I hope they'd do everything possible to cure me before mercifully putting me down. Females don't have a monopoly on class.