Creating characters is like throwing together ingredients for a recipe. I take characteristics I like and dislike in real people I know, or know of, and use them to embellish and define characters.
Cassandra ClareIn a closed urban fantasy, the magical world is secret and no one knows about it. In an open urban fantasy, everyone knows about it. So with a closed fantasy, you have to figure out how the world keeps itself secret, and with an open one, you have to figure out how knowledge of magic has altered the world we know.
Cassandra Clare