A half-elf is a mythological or fictional being, the offspring of an immortal elf and a mortal man. They are often depicted as very beautiful and endowed with magical powers; they may be presented as torn between the two worlds that they inhabit. Half-elves became known in modern times mainly through J. R. R. Tolkien's Middle-earth writings but have origins in Norse mythology. A half-elf appeared in Lord Dunsany's 1924 book The King of Elfland's Daughter.
In Middle-earth, half-elves are the children of Elves and Men, and can choose either Elvish immortality or the mortal life of Men. The elf-maidens Lúthien and Arwen in Tolkien's works both chose mortality to be with the Men that they loved. Scholars have noted that this enabled Tolkien to explore several key themes, including love and death, time and immortality. As a Catholic, he believed that Men, freely choosing to let go, gain release from the world's limitations; whereas if they tried to hold on to life and material things, they would end in darkness. His Elves – except for half-elves – were unable to gain this release. In On Fairy-Stories Tolkien wrote that since men write fairy-stories, these concern the escape from death; and conversely that Elves would tell human-stories about the escape from deathlessness. Since their popularisation by Tolkien, half-elves have become widely-known in role-playing games, and in turn in video games and spin-off films. The role-playing game Dungeons & Dragons features its own race of half-elves, including the character Tanis Half-Elven.