What name did J.R.R. Tolkien give to the sudden joyful turn in a fairy tale?

J.R.R. Tolkien called a sudden joyful turn in a fairy tale a eucatastrophe.

Tolkien introduced the term eucatastrophe in his 1947 essay “On Fairy-Stories.” He formed it from the Greek prefix eu-, meaning “good,” and catastrophe, referring to a decisive reversal or turning point. For Tolkien, it described the unexpected recovery or deliverance that produces joy at the end of a good fantasy story.

He distinguished eucatastrophe from a shallow happy ending. The important feature is that the favorable turn seems surprising while remaining meaningful within the story. Tolkien considered this effect central to fairy-story structure and linked it to his idea that fantasy can offer readers consolation.

Tolkien also described the Christian Resurrection as the greatest eucatastrophe in the real world, reflecting his religious interpretation of the concept. The word is sometimes confused with mythopoeia, which means the creation of myths, or subcreation, Tolkien’s term for imaginative world-building. Those ideas are related but do not name the sudden joyful reversal itself.