In other words, more than the profound lessons on the corrupting influence of power, more than the stirring battle scenes, more even than beloved characters like Frodo and Sam, readers came to Tolkien’s books for the rich, magical world that they built out of his words. Martin has taken this lesson to heart in his work — as have some of his most successful contemporaries, like the late Jordan — pulling fans into constructed worlds every bit as elaborate as Tolkien’s. And readers, it seems, can’t get enough. Indeed, for many readers and no few writers of fantasy, world-building is the very heart of our genre. –NPR.