This novel is a difficult one to review. Thoroughly engaging all the way through it presses a philosophy upon the reader and is not concluded in a satisfactory way.
Zelazny's writing is fantastic and his prose, while mostly simple, flows like rolling hills. The backdrop is a world that could be ours in the past, future or alternate present; however it could easily just be another planet or dimension. What it is, as with most of his writing, is unique.
It's through E. Gary Gygax I found this story as it was something that helped inspire Dungeons & Dragons. It's easy to see how the main character inspired the Thief as used in that game. It's also heavily compared to Vance's Cugel stories which I'm reading shortly (after Princess of Mars). In most reviews I see that Jack is seen as something less desirable than Cugel, so it should be interesting.
I love how the story begins and draws out the depth of character and setting with ease and majesty. I follow along and have trouble putting the book down despite the overly long chapters. The characters, powers and the split between science and magic is quite endearing. For much of the book I'm enthralled.
Then it veers left and I spend too much time with furrowed brows, wondering where Zelazny is going with this. It presses the philosophy that there is no “truth” but simply what each person perceives is true, which I think is a philosophy that makes people feel better about their secrets and hidden things but ignores the idea there could be an actual baseline truth the perceptions are skewing from.
Along with the left-veer, the reader may lose empathy with the main character, which doesn't lend itself to feeling attached to the novel when completed. Still, Jack of Shadows was unique and interesting.
The prose is 4/5
The ingenuity is 4/5
The ending is 1/5
I would still pick up any other Zelazny book and give it a whirl. He can certainly write and Jack of Shadows has some worthy moments despite crashing and burning in the end.