The world of The Witcher novels, stories and video games - otherwise known simply as 'the Continent' - is a dark fantasy world of magic, monsters, heroes and villains. There are humans, elves, dwarves, and a wide variety of monsters that howl and bray at the edges of civilization as well as far darker, ancient things that lurk in the places that men have forgotten about. Ever since a cataclysmic event - dubbed 'the Conjunction of the Spheres' - the world has been a dark and dangerous place, and Witcher work has never been better.
Fifteen hundred years ago, elves, gnomes and dwarves lived on the lands of the Continent - until the world was forever altered by the Conjunction, an unprecedented magical event that left the world inhabited by packs of monsters - vampires, werewolves, ghouls and other unnatural creatures - and soaked in chaotic magical energies. They say the first humans appeared during this event, too, relics of their own world since destroyed. In five hundred years, these humans have come to dominate the world, setting up vast empires and driving the elves and dwarves into the wilderness or corralling them to be treated as second-class citizens.
The world is one of war and bloodshed. The southern empire of Nilfgaard has invaded the Northern Kingdoms and doesn't appear to be set on stopping until the whole of Temeria and Redania fall under their black banner. In the wilderness, the non-human guerilla group known as the Scoia'tael continues their covert war against the reigning powers. More than ever before, do monsters - human or otherwise - prey upon people. Amidst this backdrop, however, people claim to see signs and portents of the Final Age. The time of prophecy may just be at hand.
The Witcher-1 theme is set some point prior to the events of The Witcher 3: The Wild Hunt and after the events of The Witcher 2: Assassin of Kings. It is a world gripped by war and terror, where there is no black and white but merely varying shades of grey.