[Note: I’m going to be winding World of Wonders up in a few weeks. In the meantime, enjoy!]
I mostly re-write classical stories, because that's what I'm good at.
"Sir Gawain and the Green Knight and Ham" is a riff on a Medieval romance. Same characters, same basic plot. Different theme. Very different theme.
I'm currently pitching--without notable success--a riff on "Romeo and Juliet" called "Capuleft and Montaright". Similar characters, similar basic plot to start off with, very different theme and the climax is something more suited to a Christmas panto than a tragical romance.
The next thing I've got planned is a riff on "Gilgamesh", which I'm looking forward to. In the meantime, I'm continuing to slog through a foolish experiment with a novel plot, which I'm not very good at.
There is a whole literature on plots and plot variety and plot possibility. Kurt Vonnegut's famous theory of graphical plot provides one kind of taxonomy, albeit a literally one-dimensional one. He is outdone in this regard by the mono-myth folks, who insist everything is "Star Wars", or possibly "The Lion King". The very fact that I have to point to those specific movies and not, say, "My Dinner with Andre", proves them wrong. Tolstoy's theory--which isn't actually due to Tolstoy, nor to John Gardner--is on the meme at the top of this post--albeit in slightly amended form--and is another view of the only possible plots. On this basis, I'm guessing "King Lear" is "Godzilla vs Megashark."
In reality, there are an infinite number of possible plots, but most of them aren't very interesting. And some of us are better at coming up with them than others. The confluence of events at the end of Kim Stanley Robinson's "Gold Coast" is not an example of any "type" of plot: it is as uniquely individual as it is surprisingly inevitable, which is what Aristotle advocated for in his "Poetics".
Modern writers tend to value novel plots, and this is understandable: the literary output of the past year likely matches that of the entire Western world in the preceding five thousand years. If you're trying to stand out amidst all that, novelty is of value, for those who can do it.
Personally, I mostly can't, so I may be a little biased in my attitude toward visitations from the Ghost of Plot-lines Past.
Classic stories are classics for a reason: they speak to various needs of the human mind. Those needs cover a huge range, so classic stories cover a huge range of plots. One thing humans want is affirmation of their most deeply held beliefs, which can vary from the most Panglossian optimism to the most nihilistic cynicism, so there are plots and characters to match, throughout history.
Hate humanity? Aeschylus's Agamemnon or Shakespeare's Titus Andronicus might be for you! Think humans are pretty clever and capable? Try Homer's Odyssey. Find life rich, violent, heroic, sexy, and far too short? Gilgamesh.
Using someone else's structure as an armature on which to hang a work of art on is (almost) as old as art itself, and no impediment to originality or variety. The use of Bible stories and scenes in Renaissance art shows how a single subject can be imbued with enormous artistic individuality. Compare Michelangelo's David with Donatello's or Bernini's, say. Michelangelo shows us a muscular, powerful, thoughtful, almost contemplative David, sizing up the foe. Donatello's bronze David is this smug twink who has somehow killed a giant. Bernini captures David mid-fight, just as he is about to sling a stone, and leaving no doubt as to his complete and consuming focus on victory.
This is the tradition I'm drawn to: looking for a classic story that resonates with me, and reworking it toward my own ends. Because original plots are not something I can do very well.
I take some solace in the fact that Shakespeare couldn't either. His one original plot--Hamlet--is a mess. It's far too long, and yet so tightly integrated it can't be cut. If you watch Kenneth Brannagh's full-text version you'll see the imponderable length. If you watch Mel Gibson's abridged version you'll see how it can't be cut: Gibson's version loses the Fortinbras subplot, which you realize in Brannagh's version is actually central to the theme of the brutality and meaninglessness of life.
Otherwise, Shakespeare lifted his plots from elsewhere. "Romeo and Juliet" came from an Italian poem that was translated first into French, then English, then used as the basis for a number of plays, Shakespeare's version included.
Many of Shakespeare's history plays came from the Holinshed Chronicles, a nominal account of the kings and queens of Britain. Other sources, including other contemporary plays, fed Shakespeare's creativity. He often messed with the source material: according to Holinshed, MacBeth was a good king with a long reign. Oh well.
Shakespeare was writing in an intensely competitive, economically difficult, environment, and he did OK. Even in the modern world, we see genres and subgenres that are basically the same plot and characters repeated endlessly, ringing small changes on the theme, if that: in romance only the characters change (slightly).
For myself, I'm good with words, I'm OK with characters, and I'm at best so-so with plot. The whole concept of the linearity of time is something I struggle with. So when faced with a novel challenge, as I was when writing a 600 word rhyming story on the the them of "law abiding" using the emotion "speechless" in the genre of "rom-com" for a contest, one of my experiments was to fall back on a classic plot. This is the last of these variations on a theme, but it's probably my favourite of the three of them.
Faust in Love a precisely 600 word rhyming story by TJ Radcliffe Chumly Faustus Featherstone the Third checked the camera and then spoke the word that fired the nascent spell. A burst of smoke revealed a demon wrapped up in its cloak, looking like a young Lord Fauntleroy. "You know that I want Helen, she of Troy, in times gone by the one most beautiful, to be my wife: submissive, dutiful and all that I desire," Faust said. The imp handed him a contract, short and limp. "Standard terms," the demon said. "She must fall in love with you, not yield to lust, and also say to me 'Hell-spawn, away' or in a year, precisely to the day I will come to claim your mortal soul. Do you agree to lawfully abide by this contract when she's by your side?" Faust signed the dotted line, "That's how I roll." So she appeared, speechless and afraid, jerked through time, a dusky Grecian maid. Her eyes grew wide. He took her royal hand and looked into those storied eyes and face "that launched a thousand ships". She turned and raced into the forest. After her he chased with the demon's laughter in his ears. In arrogance he captured her, and kept her in a state of luxury. She wept a day or two, then effortless command came back to her. With gestures she'd demand food and drink, a bath, a shady place where in the garden pond she'd see her face. A maid from Ethiopia became her servant and companion, old Lejane. Throughout it all she did not speak a line. "What do the doctors say? She's like a mime," Faust asked of Gieves, his trusted, staid valet. "When she was dragged so forcibly away by Paris in that ancient age, her throat, her vocal cords, were torn. Odds are remote she'll ever heal the loss," Gieves told his boss. Faust felt the point of time's relentless sword, yet he knew he must abide by law: he looked for loopholes but he found no flaw. A pantomime of courtship filled his days without the least to show for it. His priest, an expert in the languages of Greece, tried Ionian and Doric modes without success. Faust's glorious abode became her royal palace, but he felt the days slip past, 'til finally he knelt down at her feet and took her royal hand: "Ἑλένη, Ἑλένη! I've schemed and I have planned to own your soul! Now you have mine! I am a man who faces doom! Why don't you speak?" She rolled her eyes and waved him off in Greek. The day approached, and Faustus felt askew for he had come to love her, strong and true. The garden held him when the imp appeared. Lejane was not far off. "It's what I've feared! Now go and get my lovely silent Dear." Instead she whistled, sharp, complex, and clear, and Helen whistled back, and then came near. He looked at her, struck speechless in his turn. Lejane explained, and hope began to burn. "Herodotus said Ethiopians spoke like the bats. I'm one custodian of this ancient skill. Though it's been long since Helen's people spoke to mine in song with work we've forged a link that's deep and strong." In a trice he'd relayed all the words his love must say. She whistled like the birds and the demon howled in his defeat for the contract had no clause to treat which language her dismissal was to use. And she had grown to love her Faust. To lose him to the devil was not her desire, and so as one they whistled up love's fire.