The embargo on the J.K. Rowling novel “The Casual Vacancy,” reportedly one of the most draconian non-disclosure agreements in the history of publishing . . . did not quite work. ¶ Thursday is the release date for the first book for adults written by the empress of Hogwarts. Reviews were embargoed until 1 a.m. and book sales until 3 a.m. Since Rowling’s Harry Potter books have sold more than 450 million copies worldwide, the release of her new book — even though it is set in an unmagical British town called Pagford — is one of 2012’s largest publishing events. ¶ Thus, it is a test case for the common, if unloved, practice of forbidding booksellers from selling the book in advance of the embargo date, and forbidding media outlets from reviewing said tome before the date the publishing company decrees. The practice generally has several intents: to make sure books are in stores when readers hear about them; to retain the news revelations in nonfiction books; and to try to bottle up interest in big fiction titles, propelling them onto bestseller lists with an unusually high number of immediate sales.

“For franchise authors, you want to drive it to Number 1 by having everyone buy it the first week of release,” said Elyse Cheney, a literary agent in New York.

Rowling, who is nothing but a franchise author (she is the first in the world to earn more than $1 billion in book sales), added spice to this release with an unusually strict legal document that its publisher, Little, Brown, reportedly imposed on prospective reviewers.

The Independent in London reported a clause that not only required signees to hold off on sales and reviews but also forbade them to even mention a contract.

But — and this almost always happens — somebody got the book anyway.

When critics are supposed to abide by rules, the urge to be the first can be irresistible. (Istock/Istock)

The Associated Press and the New York Daily News (and perhaps others) said they managed to get early copies of the book, and they published reviews Wednesday. AP reported it did not sign the contract but “purchased” the book; the Daily News saidthe novel was “obtained.” Because they alone had reviews, those two organizations set the tone for readers’ perception of the book.

The Post and other news organizations observed the embargo, running reviews Thursday.

Just about nobody was happy.

“I couldn’t even get an embargoed copy to review,” said Dan Kois, editor of the book section for the online magazine Slate, which is part of The Washington Post Co. “They wouldn’t send it to us. They had very clear levels to this campaign.”

“I had to sign affidavits, more than than I have to do for a [Bob] Woodward book,” said Mark LaFramboise, senior book buyer at Politics & Prose. As of late Wednesday, he said, the landmark Washington store had yet to receive the copies that were to go on sale Thursday morning. “It’s hard to break an embargo when you don’t have the book in your store.”

The Post and the New York Times refrained from publishing their staff-written reviews online Wednesday, though The Post put AP’s review on its Web site. The Post’s executive editor, Marcus Brauchli, said he thinks the publishing industry is ultimately “fighting a losing battle.”

A spokeswoman for Little, Brown said she would have a company representative call for comment on this article, but no one had done so by press time.

This sort of struggle between publishers and media outlets has been small-arms combat for years. With some books, in which authors and publishers have signed exclusive excerpt rights with magazines or newspapers, there is a clear business mandate to preserve those rights and to keep others from writing about the material.

But other times, book agents, publishers and reviewers say, it’s about trying to create an impression of pent-up demand, with a flurry of reviews concentrated in a few days.

Connie Ogle, books editor for the Miami Herald, and LaFramboise, the Politics & Prose book buyer, both noted a similarity between some embargoed titles and B movies that are not made available to critics for pre-screening.

“There is a core audience that is going to go see the movie or read the book anyway,” Ogle said, “and those films or books often tend not to have a long shelf life.”

Woodward, the Post editor whose books have been massive bestsellers (and subject to strict embargoes), said Wednesday that such a contract was in place in 1976 on “The Final Days,” the second Watergate book he wrote with fellow reporter Carl Bernstein.

Gossip columnist “Liz Smith got a copy and ran a story,” he said, adding that leaks have happened to almost all of his books, including the latest, “The Price of Politics.” “The idea is to control the rollout and it always has mixed results. . . . If you can keep [the leak] to within a few days, then I think you’d say it had worked.”

Of course, that’s about the best it ever gets.

Total Recall: My Unbelievably True Life Story,” by Arnold Schwarzenegger, is due out next week and has a strict embargo. Which has already been beaten by the New York Daily News.

“I still don’t know how they got it,” said Jonathan Karp, executive vice president and publisher of Simon & Schuster, the book’s publisher.

The main reason embargoes tend to fail, everyone agrees, is because the cracks don’t have to be wide. It takes only one person, at one point in a vast chain of distribution, to break the link.

Rowling’s Potter books were models of corporate control of embargoes, with midnight parties at bookstores for the release. Leaks were rare.

Still, Chauncey Mabe, the books editor at the Sun Sentinel in Fort Lauderdale, Fla., during those years, beat the embargo on the last four books in the Potter series.

“It was good, old-fashioned reporting,” he said Wednesday. He beat the first embargo by persuading a friendly bookstore employee to allow him to read the book in her office, with the door closed. On the latter books, he talked a different store’s owner into letting him take the book home, with the cover concealed.

“It was total cloak-and-dagger. I loved it.”