The stories are set on the Continent, which was settled several thousand years earlier by elves from overseas. When they arrived, the elves encountered gnomes and dwarves. After a period of war between the elves and dwarves, the dwarves retreated into the mountains and the elves settled in the plains and forests. Human colonists arrived about five hundred years before the events in the stories, igniting a series of wars. The humans were victorious, and became dominant; the non-human races, now considered second-class citizens, often live in small ghettos within human settlements. Those not confined to the ghettos live in wilderness regions not yet claimed by humans. Other races on the Continent are halflings and dryads; werewolves and vampires appeared after a magical event, known as the Conjunction of the Spheres, where many other hideous and dangerous creatures emerged.

During the centuries preceding the stories, most of the Continent's southern regions have been taken over by the Nilfgaard Empire; the north belongs to the fragmented Northern Kingdoms. In order to destroy the dangerous and evil beasts of the land, sorceresses stole human children from their homes and were subject to intense alchemical proccesses, mutations, and incredible physical and magical training. They are transformed into extremely quick, and skilled, and powerful monster hunters known as Witchers.