Story structure
Allegory
A narrative carrying two meanings at once: a literal story and a second, systematic symbolic one about moral or political ideas.
An allegory is a narrative that carries two meanings at once: the literal one and a second, symbolic one, conveyed "through symbolic figures, actions, imagery" that stand for moral or political ideas. The Greek roots mean "speaking about something else," and the article's examples run from Plato's Allegory of the Cave and Bunyan's The Pilgrim's Progress to Orwell's Animal Farm, where the pigs stand for figures of the Russian Revolution, and Arthur Miller's The Crucible, an allegory of McCarthyism. The article contrasts allegory with symbolism, which "strives for a unity of object and meaning": the allegorical image is a fragment pointing into a wider web of meaning.
The craft decision is legibility. The tighter and more systematic the second meaning, the more plainly the work reads as allegory; loosen it and the same material becomes theme argued by implication, the sustained ambiguity of magical realism, or what Tolkien, who stated "I cordially dislike allegory," called applicability.