Great fanatasy (world-building) literature enhances Chekhov's Gun. In Tolkien's stories everything has meaning and is used somewhere and somewhen else. But not

Great fanatasy (world-building) literature enhances Chekhov's Gun. In Tolkien's stories everything has meaning and is used somewhere and somewhen else. But not necessarily in the same story. In The Lord of the Rings there are hundreds of "guns" hanging at the wall, which are not directly involved in this three books' story. But the reader feels that they are not only decorations. And the reader could do some research on Tolkien's work to find out about their story and importance for the characters' backgrounds. That makes the magic I believe.