Quote Originally Posted by Batcathat View Post
Sure, there are obviously lots of works with undefined magic without a trace of Deus Ex Machina and as well as the opposite (for example, the bending in the Avatarverse is fairly well defined, but that didn't stop the Deus Ex Turtle which I hate with the power of a thousand exploding firebenders...), but I'm still convinced that "magic does whatever" leaves more room for lazy resolution by authors than "magic does X, Y and Z".
Sure less defined magic has more potential for lazy resolution, but mostly because it has more potential for almost everything. Really the only thing that it can't do is the clever use of very specific pre-defined abilities plot. Since I think this is mostly just hard sci-fi warmed over into something safe for superheroes and authors who are bad at math, that's a loss I don't mind.

But what is gained is a gloriously rich universe of metaphor and feeling and WTF moments. Personally I love a good solid WTF moment, what it loses in plot cohesion it more than gains in getting me invested in seeing what lunatic thing the author will think of next. Elizabeth Haydon' Symphony of Ages books are full of these, for instance the bit where the protagonists spend six hundred years or so walking along a giant tree root that runs through the core of the planet, the time a side character's innards turn into an evil plant, or weaponizing what is basically Moria's sewage system against a dragon.