I promised to get back to these posts, and I had a specific request for the differences among high fantasy, epic fantasy, and low fantasy. When I talked about fantasy, I discussed the various tropes and methods that can be used to categorize fantasy into different sub-genres without actually spelling out definitions for any of them.
This was deliberate.
The single biggest truth about defining genres is that someone is always going to be unhappy with where you draw the lines, even if you take the time to say that you’re just explaining how you use the terms. Believe it or not, I don’t go around trying to pick fights on the Internet. (Not in person, either, except — I still cook better tacos than my older brother.)
There are two basic definitions of high vs. low fantasy out there: one based on the characters’ positions in life (kings, queens, knights vs. the more common person), and one based on how much magic is used in the world. Similarly, some people and sites (such as Wikipedia) will conflate high fantasy with epic fantasy, while others will separate them based on scope or other characteristics (see Fantasy-Faction, for example).
I personally don’t care for the fact that portal fantasy and world-within-a-world fantasy (which I see as a subset of contemporary fantasy, YA, or middle-grade) often get lumped in with high fantasy. I feel that the action of crossing between worlds — whether it’s going through a wardrobe or taking a train at Platform 9-3/4 — creates a different story form.
Thus, because I don’t like the inconsistency of the terms or the broad groupings that may happen, I don’t use high fantasy or low fantasy to describe a work. I might specifically say, “This is a low-magic secondary-world fantasy,” but I’m not going to say, “It’s low fantasy because of the magic level,” or “It’s high fantasy because it’s an obvious secondary world.”
I talked a fair bit in April about things that I felt made something an epic fantasy — scope, stakes, big themes (such as, but not limited to, good vs. evil), magic, quests, extensive world-building, and the like. If you care for another, more cohesive view, there’s a post on Fantasy-Faction about epics showing how the world changes — definitely worth a read.
To summarize: genre labels are only useful if everyone agrees on what they mean. High, low, and epic can all be broadly subsumed under the label “classic fantasy,” which is a broad category, but can be understood by those who don’t spend weeks arguing fuzzy boundaries with other genre geeks.