I'm already imagining a grumpy old thaumaturge complaining: "You can't do that with thaumaturgy! What do you think this is, magic?!"
Good one! I think Bare Mettle should incorporate that somewhere in the game.
calithlin pretty much said it all. My definition of low-fantasy is a world that is inhabited by men, unlike the Lord of the Rings film where you have various races, but various fantasy creatures dwell in the hiding, or if among men than in disguise (witches).
There is no pure evil that tries to destroy the world, but magical evil (non-human, appears evil to man, hence "evil" the term used by men) and a very powerful one does exist in the world, but is never really seen and its motives are largerly unknown and because of this is often considered a myth.
It's a bit like in Thief. The pagan god, the Trickster, was believed in, not only by the worshippers but also by the opposing Hammer order. The main protagonist did not believe in it, too, untill he painfully discovered that the myth is real, but also has a real physical shape, so it is an ancient, very mighty creature, that by the way existed among men in disguise. That also brings an unanswered question - does the god of the Hammer order exist, too? Thief is low-fantasy, too. Did I already mention how much I love that game?
As you see questions and uncertainties are part of low-fantasy. In fact I believe low-fantasy is far more mysterious than high-fantasy, because in high-fantasy the magical is common and a normal thing, while in low-fantasy it is very exotic and unique and extremely thrilling. Also, if the magical things enter the domain of men (their normal every day life), it is a shock.
Conan (the film) is a good example of low-fantasy.