Can every fairy tale be built from the same 31 pieces?

Not every fairy tale, but a startling number of Russian ones. Vladimir Propp, a Russian and Soviet folklorist, took apart a hundred folktales from Alexander Afanasyev's collection and looked for their simplest, irreducible units. He found 31 of them, which he called functions, and he found they occur in a specific, ascending order. No single tale uses all 31, but whichever ones a tale does use appear in the same sequence.

Here is what a function looks like. First the hero is forbidden to do something: "don't go there". Then the prohibition is broken. The villain harms a family member, perhaps by abduction, theft or banishment. And in the last function the hero marries and is rewarded, typically by ascending to a throne.

Propp went further. He concluded that every character in these tales can be resolved into just seven abstract roles. A role is not a person: one role can be spread over several characters, or several roles can be played by one. A father can send his son on a quest and hand him a sword, acting as both dispatcher and donor.

Propp published his Morphology of the Folktale in Russian in 1928. It influenced Claude Lévi-Strauss and Roland Barthes, but it was generally unnoticed in the West until it was translated in 1958. Today the idea has been applied to literature, theatre, film, television series and games, though Propp himself used it specifically for the wonder tale.