6 Sci-Fi Book Series With the Best Lore, Ranked

Fantasy can get away with hand-waving how the magic works, but sci-fi usually can’t. So, once a series sets up a rule about physics or technology, breaking that rule later just to save a character is cheating. That constraint actually makes good sci-fi lore harder to build than fantasy lore, since every made-up law of the universe has to sound like it could theoretically work.