I really loved these books - they worked on so many levels.
Here is a fantasy that does not fit into the stereotypical faux medieval fold. Instead, Duncan creates a convincing alternate universe that is filled with a geography, flora and fauna that are convincingly "other". He creates a whole culture within this world that is not just ripped off from european or japanese cultures, as so many writers do. Instead he invents a world that works on its own merits, and has a culture that makes you want to explore it.
And then he drops into this rich and diverse world a hero character that is - as the title suggests - reluctant. Ripped from a dull life on our world he finds himself put into this other world by a god calling himself just "Shorty". He has a task to do that only he can fulfill - but his journey of discovery to fulfill the task is long, arduous and very very interesting.
Yet despite the apparent flippancy of the god, Shorty, there is something deep going on in this story too. The book repays reflection, as it allows you to think of issues such as free will, miracles, science and magic, love and friendship, slavery, and the power of information.
I have no idea whether the author intended it to be a theological work, but one can certainly find many of the themes that C S Lewis would put into his works in this book and the sequels.
I would love to see a role playing game adapted from this book too. It would be a welcome changed from the Dungeons and Dragons games, but already has a concept of set professions.
But whatever angle you take, my recommendation is the same. read this book. It is worth it.