When a King is drawn from the circle of cards, that player must pour whatever it is they are drinking into the center cup. Going clockwise, players draw cards from the circle.
In Kings Cup, an empty cup is placed in the center of the table along with entire deck of cards spread out evenly around it in a circle.
I'm going to give you the basic rules I have used since I first started playing. There are many different variations of playing Kings Cup / Circle of Death, but the rules are essentially the same.