In Defence of a Magic Circle:

Magic circle continues to be a hotly debated term in game studies. The term is intuitively accepted, useful in describing the difference between play and non-play; a handy metaphor that acts as intellectual shorthand for a more complex set of social relations. However, if it is not clear what ‘magic circle’ is shorthand for, then the term can mud- dle thinking. For example, when taken too literally, it can cloud our understanding of how play is bounded.