There's a word often bandied about when people discuss books, particularly fantasy and science fiction books, which often involve the creation of worlds unlike our own. That term is (perhaps unsurprisingly) worldbuilding. And if ever there were a paradigm case for worldbuilding, Ringworld would be it. The eponymous structure is not a planet but, for all intents and purposes, functions as one. With a simple concept and a little bit of physics, Larry Niven has a striking novum that's brand, setting, and mystery all in one. If only Ringworld lived up to that potential….
The first half of the book wasn't bad. Watching Nessus recruit Louis, Speaker To Animals, and Teela was a fascinating look at Niven's far future. I can't say I was able to visualize the puppeteers very well, but I got the idea of transfer booths, cat-like Kzinti, hyperdrive, etc. This is my first science fiction book by Larry Niven, and it instilled in me a good opinion of Niven's ability to balance carefully hard science fiction concepts (like an adherence to relativistic travel) with soft science fiction (an emphasis on the sociological effects of spaceflight and unexplained plot devices like hyperdrive). Specifically, I loved his sociological asides, such as Louis' speculations about how much Nessus and other Puppeteers have interfered with human and Kzinti development. Niven makes good use of the time it takes to reach and explore the Ringworld itself to show us his version of the future.
Alas, once the action is restricted to the Ringworld and the new goal is to discover any remaining pockets of Ringworld Engineer civilization, the only thing remarkable about the story is the alacrity with which it becomes unremarkable. It's apparent that something happened to cause civilization to "fall" on the Ringworld. Louis' speculation about a microbe that ate away at complex compounds eventually proved correct (and very cool, I'll admit). That isn't enough to save the book from a mediocre trip from the crash site to an abandoned city, where they meet up with a surviving Engineer (who is more like a prostitute, posing as a god). Along the way, we had to endure torturous talk about how Teela was "bred for luck". As a result, she has almost zero free will, because nearly all her actions result from chance. I'm sceptical about accepting this whole "breeding for luck" idea, but suspension of disbelief compels me to shelve the matter and ignore Niven's incessant speculations. If only Niven hadn't similarly ignored the most interesting part of Ringworld itself: its inhabitants!
I'm talking about the fallen descendants of Engineers, of course, not the original inhabitants. Louis himself, near the very end of the book, reflects on the fact that the Ringworld is so vast as to support a great diversity of cultures. And Nessus makes a valid point that, because it isn't a planet and the Engineers could just transmute matter from one form to another, the Ringworld has no metal ores to mine. The only way to make tools is to scavenge what's left from abandoned cities. It would have been interesting to see how those diverse cultures and see how they've adapted to the unique challenges of living on a ring (which they think is an arch). Aside from a few scenes where Louis and the others pose as gods and meeting Seeker, we don't get a lot of face time with the natives. Niven and his characters are more obsessed with what happened to the Ringworld Engineers and (understandably) getting off the Ringworld.
It might seem strange that I didn't share their obsession. After all, I'm a technophile. The Ringworld is an awesome idea, and I was curious to discover who had built it. Nevertheless, I'm jaded enough that I was sure—especially after learning that civilization had fallen—that the answer wouldn't be very satisfactory. I was right.
After shrouding it in so much mystery, Niven reveals that the demise of Ringworld civilization wasn't nearly so mysterious. Louis was right about the microbe. The Engineers are dead, mad, or integrated into the fallen societies scattered around the ring. Only Pril is left to tell her story. But because Louis and Nessus had already unravelled much of that story on their own, there wasn't much left to serve as a surprise or a twist.
But it's the journey, not the destination, right? Aside from my complaints about not showing us more Ringworld culture, it's true that Niven gives us plenty of episodic events on the way toward the rim wall. We get killer sunflowers, a massive storm, and a floating castle with a holographic map. Ringworld would be an awesome place for a roleplaying game, just because it's such a wonderfully built world.
So in case I haven't browbeaten you enough yet, I'll be explicit: Ringworld is great because of its worldbuilding and sucks because of its story. If you're one of those people who likes reading about intriguing hypothetical constructions like rings, Dyson spheres, etc., then you should probably read this book. However, one cannot draw much satisfaction from the mystery of the Ringworld or the characters who try to solve it. Unlike the Ringworld, they aren't built nearly so well.