In some fictional worlds, using magic doesn't only get a certain desired effect, but causes something else to happen as well. This could be something small, like snowflakes appearing every time a character shouts "Shazam!", to more serious issues, like the appearance of items that could be potentially life-threatening. Depending on the story, this might be a big problem for if the magic practitioner can't handle the side effects very well, or it might just be a cute little quirk, likely of a symbolical nature. In any case, the side effects do not
have to have any influence on the magic spells themselves, or threaten the practitioner directly.
Compare Equivalent Exchange
, where the use of magic does
have a direct influence on the practitioner. See also Electromagnetic Ghosts
, which deals with one