I used to view the entire Harry Potter phenomenon with a bit of bemusement. I had already been reading fantasy books for years when Harry Potter and the Sorcerer's Stone was released, and while I enjoyed it, I never imagined that it would turn into the international phenomenon it has become. From my perspective, J.K. Rowling was simply following in the footsteps of Diane Duane's So You Want to Be a Wizard?, Diana Wynne Jones's Witch Week, among many others. I couldn't understand why people were going nuts over Harry Potter when these other books had been largely ignored, by comparison.
There is no denying that Harry Potter satisfies all of what I think are the requirements for good fantasy (not necessarily an exhaustive list):
- An engaging, original, well-realized fantasy world
- Simple yet evocative writing which can be understood after one reading
- Plenty of action
- A high "that would be so cool" factor
- A well-defined objective to be accomplished by the hero
On the other hand, so do both of the titles I mentioned above, as well as thousands of other fantasy novels, for adults and children, none of which have become anywhere near as popular as Harry Potter, and for a long time, I couldn't understand why.
However, after reading all seven of the Harry Potter books in rapid succession this month, I've realized that the Harry Potter books do indeed have something that many fantasy novels lack: compelling characters. Although she frequently defines them with melodrama and outrageous emotional outbursts, Rowling's characters are undeniably human. Harry and his cohorts suffer all (and then some) of the uncertainty, pain, anger and fright that people fighting ultimate evil while simultaneously going through puberty might be expected to feel. By contrast, many fantasy heroes, after being plucked from their humble beginnings, stoically put real life on hold and forge ahead with whatever Herculean task the author has set them without bothering with pesky emotions too much.
The requirements I outlined above make for great escapist writing. If you want to take a mental holiday for a while, then any book satisfying those requirements will do the trick. However, to get people really worked up about something, an author needs to do more than create a world that people care about, he or she needs to create characters that people can laugh with, cry with, yell at when they're being stupid, and fall in love with, and Rowling does this well. Not with very much finesse, but well.
That's not to say that Rowling has a monopoly on inspiring empathy; the success of the Harry Potter series undoubtedly involved a certain amount of luck as well as talent. However, the books certainly had the potential to become wildly popular, not to mention the widest possible target audience, so in hindsight, it shouldn't have been a surprise that they did.
For adult-oriented fantasy that features emotions, check out George R.R. Martin, Robin Hobb, and Terry Goodkind.