"Well, the conceptual structure of chess magic is useful because instead of being limited by whatever spells happen to exist to do the thing I want, I can construct a narrative out of distantly chess-based metaphors and as long as I have the right pieces to fill it and can cover any gaps with things like my focus stone, it works. I'd probably be most comfortable inventing a new system if it had some kind of structured conceptual basis like that. Not necessarily based in a game of any kind."