In use on the MUX, magic is treated as any power. You have a set of guidelines for the magical ability—when, how, where, etc, you can use it, and you follow those guidelines. It's really no different than using a power or a skill with another player in a combat situation. For more subtle magics, again, you'd simply treat it as any other skill or power and use @mail or page to work out the specifics with the 'victim', or rather, target of your spell.

Some magic affects have been soft-coded on the game, so refer to the online +help magic for more information.