Elves, hobbits, dwarves, orcs, new languages, the plot, and the setting the story takes place in. It is not subtle that there is a theme of fantasy.
When compared with other fantasy fiction novels, fighting is not something that comes to mind when you read The Lord of the Rings. This is most likely a result of the time Tolkien spent fighting in World War I.
J.R.R. Tolkien's writing style can be categorized as elegant, unique, graceful, and old-fashioned. Tolkien excelled in showing his imagination in great detail, but didn't like using fancy vocabulary. Poetry is also a major element in Tolkien's work that made him stand out from others. He is widely known for the genre of fantasy. His writing is seen as inspired by Gaelic, Biblical History, Irish Mythology, Catholicism, and World War I & II.