Hainish series

When the Athsheans, the inhabitants of a peaceful world, are conquered by the bloodthirsty Yumens, they retaliate against their captors, abandoning their rules against violence and endangering the very foundations of their society.

"A deluxe hardcover edition of the queen of science fiction's trailblazing novel about a planet full of genderless beings--part of Penguin Galaxy, a collectible series of six sci-fi/fantasy classics, featuring a series introduction by Neil Gaiman. A groundbreaking work of science fiction, The Left Hand of Darkness tells the story of a lone human emissary's mission to Winter, an unknown alien world whose inhabitants can choose--and change--their gender....

Once a culturally rich world, the planet Aka has been utterly transformed by technology. Records of the past have been destroyed, and citizens are strictly monitored. But an official observer from Earth named Sutty has learned of a group of outcasts who live in the wilderness.