J.R.R. Tolkien used the term eucatastrophe for a sudden joyful escape from catastrophe in fantasy stories.
Tolkien introduced the word in his 1947 essay “On Fairy-Stories.” He formed it from the Greek prefix eu-, meaning good or well, and catastrophe, meaning a turning point or outcome. For Tolkien, eucatastrophe was not simply a convenient surprise ending; it was the sudden turn from apparently overwhelming disaster toward joy.
He regarded this effect as a defining feature of the fairy-story tradition. Tolkien also connected it with what he called the “eucatastrophic” quality of the Gospel story, while distinguishing literary fantasy from religious belief.
Readers often confuse eucatastrophe with deus ex machina. A deus ex machina is an externally imposed solution that can seem unprepared, whereas Tolkien’s idea concerns the emotional and thematic turn toward hope. The Eagles’ arrival at the climax of The Lord of the Rings is frequently discussed as an example, though the term applies more broadly.