4 ideas
In the city of Argolanda, citizens are assigned classes by periodic intelligence tests, and each class sets their income and privileges. Sneer is highly intelligent but deliberately scores low to stay in a modest class, which gives him less scrutiny and fewer obligations. He earns extra by illicitly sitting tests on behalf of other people, which draws him into the machinery that runs the ranking system.
Each citizen carries a biometric Key that works as ID card, wallet, and access pass. Controlling the token controls the person, and being cut off from it amounts to social death.
Sorting people by test scores looks fair and apolitical, so the hierarchy seems earned rather than imposed. Because the tests set material rewards, people compete to climb or strategically hide their ability rather than question who designs the scale. The ranking system fragments potential solidarity into individual score-management, and the scale works as containment, not as recognition of talent.
The novel peels back authority repeatedly. The visible class system is run by a hidden elite, and that elite is itself a subordinate apparatus answering to an outside power whose supposed strength is partly bluff. Read this way, any seemingly free system should be asked who administers it, and then who administers them. The apparent top of a hierarchy may be performing control it does not actually have.