What term did J.R.R. Tolkien use for a sudden joyful turn in a fairy story?

J.R.R. Tolkien used the term eucatastrophe for a sudden joyful turn in a fairy story.

Tolkien introduced the word in his 1947 essay “On Fairy-Stories.” He formed it from the Greek prefix “eu-,” meaning good, and “catastrophe,” meaning a decisive reversal or outcome. For Tolkien, eucatastrophe was the unexpected appearance of a happy resolution after danger or despair.

He distinguished it from a merely convenient ending. The turn should feel startling but earned by the story’s structure. Tolkien considered this kind of ending central to the emotional power of fairy stories and linked it to what he called the “joy” of their consolation.

Readers often confuse eucatastrophe with a general happy ending. Tolkien’s term is narrower: it describes the sudden reversal itself, especially when it arrives after an apparently final disaster. He also connected the idea to Christian themes, while using it as a literary concept.