An employee at Sotheby’s holds an 1843 first edition of the classic A Christmas Carol by Charles Dickens, which was auctioned off in London last week.

BLOOMBERG NEWS / SUZANNE PLUNKETT

Charles Dickens’ most popular work may be the one he didn’t write.

A Christmas Carol, the Victorian author’s classic novella, is probably the most universally known of his many works, in no small part because of the stage versions of this yuletide ghost story that are as much a part of the season as eggnog and The Nutcracker.

The enduring popularity of A Christmas Carol as theater is evidenced by a glance around stages this holiday season, where several productions based on Dickens’ story have been or are being produced — and no two have the same title or author.

There is only one book, so why are there so many plays?

Part of the reason there is no single, dominant stage adaptation of this classic is that Dickens never wrote one. And he would have found himself in a crowded field if he had.

“The book was published in December 1843,” notes Paul Davis, author of several books about Dickens and A Christmas Carol, including The Lives and Times of Ebenezer Scrooge. “By February 1844, there were eight stage versions.”

Dickens did not pen any of those adaptations and only one had his approval. Throughout his career, the British author had trouble protecting his works from piracy, and there seemed to be an especially open season on A Christmas Carol from the day it was published. Hundreds of unauthorized adaptations were staged in his lifetime, and the flow has never stopped.

“It’s an incredibly flexible story,” says Davis, a former English professor at the University of New Mexico, explaining the variety of versions. “If you ask the question, ‘How did Scrooge make his money?’ it’s not all that clear. That’s opened up the possibilities of making Scrooge a money lender, a real estate person, a furniture manufacturer — he has gone through many transmutations. And the story has kind of an instant universality to it in the way Dickens tells it.”

But besides inspiring theatrical rip-offs, Dickens’ story is widely credited with having a profound impact on how Christmas is celebrated in England and America.

We tend to think that Christmas has always been a merry, Christian holiday. But the roots of our Christmas reveling can be traced back to ancient winter solstice festivals and Roman Saturnalias. In the 17th century, celebrating the holiday had become so rowdy that it was sporadically banned by churches and governments in England and America. After these bans, a more austere approach to honoring the day became the norm. That began to change, however, in the 19th century.

“The very strict Protestants of Dickens’ times did not approve of the celebration of Christmas,” Davis says. “They thought that was too pagan. And so others were reluctant to celebrate in light of that.”

But the success of A Christmas Carol as both a book (Dickens supplemented his income by doing public readings of it for decades after its publication) and an ever-changing stage work was one of the factors that helped Christmas blossom into a more joyful holiday.

“You could say Dickens was responsible, in large measure, for restoring the celebration of Christmas because he made it accessible to those who were a little uneasy about celebrating,” Davis says.

If you make this play a regular part of your holidays, you will find that most stage versions include music. At least one director finds that easy to understand.

“I think music in A Christmas Carol is natural,” says Joel Ferrell, director of Dallas Theater Center’s A Christmas Carol, who had to choose his script from a stack of eight adaptations culled from the hundreds available. “When you do something that ultimately speaks to the joy of Christmas, that message is heightened by music. It is just such a natural part of Christmas that, even though it is a ghost story, it is hard not to include music.”

Nor does Ferrell see any mystery about the key to A Christmas Carol’s amazing endurance record — despite the myriad ways in which Dickens’ original has been stolen, altered and mutated over the years.

“Scrooge becomes that grandparent that every kid wants,” says Ferrell, who knows this work as both an actor and a director. “I think the idea that you get a second chance and then make the most of it — that’s pretty much as good as a story gets.”

Besides its many stage adaptations, there are numerous memorable versions of A Christmas Carol in the electronic media.

The following is a short list of some of the film and television productions. A Christmas Carol (aka “Scrooge”) (1951) — This British production is a traditional treatment that features an outstanding performance by Alastair Sim.

“Mr. Magoo’s Christmas Carol” (1962) — A personal favorite, This cartoon version featuring the Jim Backus-voiced, optically challenged title character as Scrooge is stiffly animated, but it is surprisingly true to the original.A Christmas Carol (1984) with George C. Scott and A Christmas Carol (1999) with Patrick Stewart — These two made-for-TV movies, separated by 15 years, have a great deal in common — both are fine productions.