The world described has a society and technology roughly similar to that of the historical 16th or 17th century, but with several crucial differences: the world is littered with "Elderglass", an unbreakable material left behind by mysterious beings known as "Eldren"; firearms have not been discovered, the crossbow being the most advanced offensive weapon known; magic exists, virtually monopolized by the secretive and malevolent Bondsmagi; the practice of alchemy offers some devices far beyond 17th century levels, such as alchemical lights which are the equivalent of electric ones.