The Practice Effect Author:David Brin From one of the most critically acclaimed and well-loved authors of contemporary science fiction, a highly imaginative and exciting story as only David Brin can write... — Physicist Dennis Nuel was the first human to probe the strange realms called anomaly worlds -- alternate universes where the laws of science were unpredictably changed. But the... more » world Dennis discovered seemed almost like our own -- with one perplexing difference. To his astonishment, he was hailed as a wizard and found himself fighting beside a beautiful woman with strange powers against a mysterious warlord as he struggled to solve the riddle of this baffling world.« less
Another good Brin book. "Practice makes perfect" brings a whole new meaning when the physics have gone a bit strange. In this, people make simple clothes out of rags and junk, and give them to others to wear and use for a while. Later, those practiced items are taken back once they are high enough quality. The upperclass has even more of a reason to make the lowerclass do all the work.