Netflix's adaptation of The Witcher follows the material of the novels very closely, though they seem to stray and take certain liberties when involving certain female character's backstories. It is filmed the same way the book ordered chapters, every chapter is it's own tale and not usually in order chronologically. You don't need to read the books in order to enjoy the show but certain story heavy scenes would make much more sense if you did. Henry plays an amazing Geralt, though I wish he was shown more, he delivers a great take on the character.