What makes a holiday movie?

If you’ve ever wanted to write a screenplay but couldn’t decide on a plot, you might consider penning a Christmas movie.

After all, the plots of holiday films are usually pretty formulaic. In fact, all you need to do is include some of these 12 key story elements, add a little snow and — “Merry Christmas!” — you’ve got yourself a yuletide blockbuster.

An anti-commercialism message

“What Would Jesus Buy?” That’s the question posed by filmmaker Morgan Spurlock’s documentary about the over-commercialism of Christmas. Although Hollywood prefers to focus on decorating, tree chopping and toy shopping, “A Charlie Brown Christmas” and its peers dare to call attention to the true spirit of the season. To quote the Narrator in “The Grinch Who Stole Christmas,” “Maybe Christmas…doesn’t come from a store. Maybe Christmas… perhaps … means a little bit more.”

A big dose of nostalgia

The biggest indication that “A Christmas Story” belongs to a simpler time is the toy that Ralphie Parker (Peter Billingsly) wants for Christmas: a Red Ryder BB gun complete with a compass and “this thing that tells time.” Can you imagine a kid requesting something that low-tech today? Much like “It’s a Wonderful Life” and “The Bishop’s Wife,” this nostalgia-soaked comedy harkens back to a time when families tooled around in Oldsmobiles, ordered toys from the Montgomery Ward catalog and tuned in every night to “Little Orphan Annie.”

A dysfunctional family (or two)

It’s probably not a bad idea to inject a little dose of reality into Christmas films. Because as much as we like the idea of a happy, huggy family singing “The 12 Days of Christmas” around the tree, most viewers know that family gatherings often entail uncomfortable silences, passive-aggressive remarks and backward weirdos like Clark Griswold’s goofy cousin-in-law Eddie from “Christmas Vacation.” For incompatible relatives who bicker under the mistletoe, see also “Home for the Holidays” and “Four Christmases.”

A tearjerker moment

Nearly every Hollywood holiday movie features a moment that’s so heartwarming (or heartbreaking) we have to yank out our hankies. You might find your eyes welling up when the nameless hero finds a silver sleigh bell in his pocket in “The Polar Express.” Or you might shed a few surreptitious tears when the entire town shows up to bail out the Baileys in “It’s a Wonderful Life.” Either way, we challenge you to watch those precious moments without whimpering.

A great holiday soundtrack

Even a bad movie can benefit from a good soundtrack (That’s right, “Christmas with the Kranks”—we’re talking to you.) You can use existing songs, as they did in “Elf” (including Eartha Kitt’s “Santa Baby), or you can commission someone to write originals, like Paramount did when it hired Irving Berlin to write songs for the movie “White Christmas.” Then, even if your movie stinks, at least the soundtrack will sell.

A ‘Santa Claus is real’ revelation

Is he or isn’t he? The existence of Santa Claus has been a hot-button topic ever since earnest lawyer John Payne held a trial in “Miracle on 34th Street” to determine the truth about the jolly old elf. (He later proves in court that Kris Kringle is “the one and only” Santa.) These days, there’s a string of holiday movies targeting unbelievers, including “Once Upon a Christmas” “Stalking Santa” and “The Santa Clause.”

A misplaced character for comic value

It’s funny when people are out of place. In “Elf,” Will Ferrell is a 6-foot-3 human raised as an elf. In the “Santa Clause” films, Tim Allen is a run-of-the-mill toy company executive who physically transforms into Santa. And in “The Nightmare Before Christmas,” Jack Skellington, the bony Pumpkin King, becomes a macabre St. Nick.

A loved one’s death

It seems like every holiday movie has someone who recently lost a mom, wife, husband or dad. In “Prancer,” an 8-year-old has just lost her mother. In “The Christmas Wife,” Jason Robards is a recent widower, while Olivia Newton John is a widow in “The Christmas Romance.” And, of course, in holiday films, you never have to go far to find an orphanage packed with children in need of a Christmas miracle.

A bad character goes good

If you ever see a character shouting “Humbug!” in a holiday movie, don’t despair. She or he will have a change of heart before the end credits roll. The tradition dates back to Charles Dickens’ “A Christmas Carol,” in which miserable miser Ebenezer Scrooge becomes the very embodiment of Christmas cheer. Billy Bob Thornton undergoes a similar transformation in “Bad Santa.” But it’s the title character in “The Grinch Who Stole Christmas” who has the biggest turnaround. After originally scheming to ruin Christmas, he winds up at the head of the holiday table carving the roast beast.

A good twist on Dickens

Speaking of Dickens, a new take on “A Christmas Carol” is the oldest trick in the book. So if you’re gonna do Dickens, you’d better have a twist. In “Scrooged,” Bill Murray is a TV programming exec tasked with heading a live broadcast of — you guessed it — “A Christmas Carol.” Soon his life begins to seem oddly similar to Scrooge’s. If you can’t think of a good twist, you can’t go wrong with puppets, as in “The Muppets Christmas Carol.”

A little dark comedy

When Halloween Town’s Jack Skellington takes over for Santa in “The Nightmare Before Christmas,” he’s still got Halloween in mind. So kids are horrified to get shrunken heads, Christmas tree-eating snakes and other ghoulish gifts. Meanwhile, movies such as “Die Hard” and “Lethal Weapon,” which take place at Christmastime, prove mayhem, humor and fruitcakes are tasty ingredients for holiday blockbusters.

A dose of holiday movie magic

How do reindeer fly? How does Santa Claus squeeze down chimneys? How does one elderly, out-of-shape man deliver toys to all the world’s children in a single night? Clearly, there’s some holiday magic at work. The same wintertime wizardry can be seen in the vintage animated television specials “Frosty the Snowman,” “Rudolf The Red-Nosed Reindeer” and “The Year Without a Santa Claus,” which combine merry messages with creative visual storytelling techniques.