I first (and last) read this some 35 years ago, and recently dug out my dusty old paperback to refresh my memory in order to participate in the discussion of it held in the Classic SF forum. Zelazny was one of my favourite authors then, and I was curious to see how this unusual tale stood up to the test of time.
Lord of Light is set in the far future on another planet, with Earth an almost forgotten memory. The planet has been settled by the crew and passengers of a colony ship from Earth, but society has developed in a strange way. The crew have commandeered all of the technical resources and keep the descendents of the passengers at a medieval level of existence. To reinforce this, the crew have adopted the identities of Hindu gods, and live in "Heaven"; a perfect city situated at one of the poles, with a vast transparent dome protecting the area.
There are two other unusual features. The more powerful of the "gods" have developed mutant powers, reinforced by technology, which match the attributes of the mythical gods. And technology has made the transmigration of souls from one body to another a routine matter. Some of the original crew members have survived in this way, transferring as they age to new bodies specially grown for the purpose. This is also on offer to the general population, but they have to earn it, or risk being reborn as an animal – a powerful coercive tool.
Not all of the original crew are happy about this situation, and the story is all about the rebellion led by one of them, the 'Lord of Light' of the title, who wishes to destroy Heaven and bring the benefits of advanced technology to all. As a part of his campaign, he reintroduces Buddhism, and becomes regarded as a great religious teacher.
The structure of the story is rather disconcerting, as only the first and last chapters are set in the "present day", the majority of the book reverting to an account of the Lord of Light's previous, failed, attempt at rebellion. As the characters are gradually fleshed out in later chapters, I found myself flipping back to the first chapter to remind myself of who was who.
The writing style is quite leisurely, the author being happy to let his characters enjoy long conversations and intellectual debates, resulting in a certain lack of tension. He also plays with words, setting up some good jokes (one of the few things I remembered from my first reading of the book was the way in which he managed to work up to the punch-line: "then the fit hit the Shan"!). While the hero is a likeable character, there are few insights into his background or the motivation for his determined resistance. Despite these reservations, the intelligence and quality of the writing held my attention to the end. Unusual indeed, but well worth the time to re-read.
A recent special edition of the New Scientist magazine focusing on science fiction is online, HERE