Imaginary Worlds by Lin Carter is a nonfiction book that explores the history and development of fantasy literature. Published in 1973, it discusses the evolution of the genre, from the early myths and legends that inspired it to the works of modern fantasy authors. Carter delves into the imaginative worlds created by authors like J.R.R. Tolkien, H.P. Lovecraft, Lord Dunsany, and many others, analyzing their techniques and approaches to world-building.Carter, who was an editor for the Ballantine Adult Fantasy series at the time of its publication, had a deep knowledge of the genre, and Imaginary Worlds reflects his love and expertise in fantasy literature. It's often considered a significant work for understanding the roots and mechanics of world-building in fantasy.