Brandon Sanderson (a popular fantasy author that I've yet to read) gives us:
Sanderson's First Law of Magics: An author's ability to solve conflict with magic is DIRECTLY PROPORTIONAL to how well the reader understands said magic.And in a recent review of a friend's book someone said:
The lack of explanation of the magic system has me hesitant to continue the series.
Now both of these are opinions. I have a different one:
I've never been aware of reading a book with a well explained magic system. I can't say how I'd enjoy it but my instinct is that if an author started to explain the magic to me as if it were a system born on the pages of a Dungeons and Dragons rule book I would walk away. I quote Sanderson here because I've seen the 'law' repeated in several places. It's entirely possible I would enjoy his work - I don't have time to find out right now - but the sentiment that radiates off the two quotes above sits uneasily with me.
Don't get me wrong - I started playing D&D in 1977 and spent man-years at it. I love magic rules, the inventive combinations that one can concoct in something like Magic The Gathering. I like understanding how things work (I am a scientist after all). However, a novel is not a role-playing game put into words. For me, for magic to be magical, rather than just weird science, it needs mystery. It is an act of writing skill to simultaneously construct the mystery in magic and the faith that it will not be abused. Gandalf's magic didn't come nailed to a system diagram. He wasn't limited to some pre-declared set of rules - two level 1 spells a day - a fireball can only be yay big - or whatever. We trusted Tolkien that along with the mystery there would be an appropriate restraint. Gandalf was never going to say 'sod this let's fly' and magic them into the air, he was never going to turn the balrog into a toad. His power enchanted more than his enemies - it enchanted us - remnants of lost lore and ancient traditions, embodied in and by the man.
If I had to frame a law it might run:
Lawrence's First Law of Magics: An author's ability to solve conflict with magic is DIRECTLY PROPORTIONAL to how well the author gains the reader's trust and draws them into his world.
But both versions miss the point somewhat. The primary reason for including magic in a book (if you're me) is for the magic of it. To give the reader chills - to excite them - to make them wonder. Magic isn't there to solve conflicts - that's what cleverness and bravery and fortune are for. Magic is there to rock.
And if you do happen to wipe out thousands of men with magic and nary a hint of a cog-wheel or subsection to rule 27 paragraph 2 ... sometimes people go with it anyhow. Because they're in there with you, they trust your vision, they're sold.
That's the magic. Writing is the magic. Rules are for games.