In keeping with science fiction traditions, Niven devotes little space to in-depth characterization. He is concerned with man's interactions with his environment rather than with his fellow man. The main characters follow familiar lines: Clave, the leader, man of action, and lover; Jeffer, the scientist; Gavving, the young hunter who comes to maturity during his adventures. The female characters, Minya, Lawri, Merril, and others, are depicted as equal to the men as warriors and scientists.

Interestingly, although the Smoke Ring dwellers are technologically backward and organized along tribal lines, Niven does not depict them as savages enslaved by superstitions. Although only the tribal scientists and their apprentices understand science, most of the characters accept scientific explanations for unfamiliar phenomena. This skepticism helps them to deal with Kendy and reveals Niven's confidence in the power of reason.

The Checker, Sharls Davis Kendy, is perhaps the most interesting character in...