Daniel Craig 's third turn as 007 is a critical and box office success, raking in $283.7 million in North America through Dec. 28 (it even returned to the top of the charts during its fifth week of release). In the U.K., Skyfall became the top grossing film of all time, surpassing Avatar, which previously held that title.

Universal is said to have assured the plaintiffs that it would not be infringing the famous spy character in its film about MI-6, but a lawsuit alleges that's what is happening.

MGM and Danjaq, rights-holders of the lucrative James Bond franchise, are now in a legal battle against Universal over Section 6, an upcoming film about the early days of the U.K.'s spy agency.

In a lawsuit filed in California federal court on Thursday, the plaintiffs take issue with "a motion picture project, in active development, featuring a daring, tuxedo-clad British secret agent, employed by 'His Majesty’s Secret Service,' with a 'license to kill,' and a 00 (double-O) secret agent number on a mission to save England from the diabolical plot of a megalomanical villain."

MGM's description is of Section 6, which the plaintiffs assert is really "a James Bond knockoff that defendant Universal is readying for production."

The project is said to be based on a screenplay by Aaron Berg, who is also named as a defendant. "Instead of creating something original, Universal and Berg decided to take an easier path, by freely helping themselves to vast portions of the copyright-protected expression that Ian Fleming created, and that Danjaq and MGM further developed."

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The plaintiffs demand that Universal be stopped from continuing to allegedly infringe its Bond works and also demand actual damages and advantages gained.

Here's the full complaint.

Allegations of theft are common in Hollywood, although rarely does a copyright battle pit major Hollywood studios against each other. Copyright protects expression and not ideas. The issue of an entertainment property that hasn't yet been fully developed could come up just like it has in ongoing litigation concerning rival studios said to be preparing new film versions of Dungeons & Dragons. Here, the lawsuit states that the parties have been communicating for some time, and at one point, Universal denied even having optioned the screenplay.

The issue of James Bond as a protectable character has come up in prior legal battles.

For example, in the 1990s, the same plaintiffs brought a lawsuit against American Honda Motor Co. over an advertisement for an automobile that featured a James Bond-type hero involved in a chase sequence with a villain. In 1995, a California judge wrote that "Like Rocky, Sherlock Holmes, Tarzan, and Superman, James Bond has certain character traits that have been developed over time through the sixteen films in which he appears."

The defendant in the case attempted to assert that the plaintiffs were trying to gain a monopoly over the "action/spy/police/hero" genre, but the judge upheld the plaintiffs' belief that Bond's character traits were sufficiently unique and well-delineated including his cold-bloodedness, his overt sexuality, his love of martinis 'shaken, not stirred' and his "license to kill." It didn't matter that many actors had played Bond over the years. The judge found this to be a "testament to the fact that Bond is a unique character whose specific qualities remain constant despite the change in actors."

MGM and Danjaq hope for a similar outcome in the lawsuit over Section 6, which is why they are identifying expressive elements like a character having a "license to kill."

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Of course, there could be other issues in the lawsuit. For example, copyright law doesn't protect bare historical facts (although the creative arrangement of facts can be copyrighted), and the Section 6 screenplay is said to state that it is premised on historical facts and declassified events. (Full descriptions of Section 6 are redacted in MGM's lawsuit.)

"That is not true," says the plaintiffs. "All of the Section 6 screenplay's core elements are fictional. … No character in the Section 6 screenplay is a real person. And all of its important plot elements are fictional and historically inaccurate. Further undermining defendants' assertion that Section 6 is a historical account of the formation of MI6 immediately after World War I, the dialogue and relationships between the characters are strikingly out of place and years ahead of their time for a story set in 1918, as Section 6 purports to be."

MGM and Danjaq, represented by Robert Schwartz at O'Melveny & Myers, are suing now upon recent reports that Universal has hired a director, lead actor and four producers to work on the film. "Contrary to Universal's November 2013 written assurances, it appears that Universal intends to infringe plaintiffs' James Bond copyrights and is doing so."

Universal declined comment.

Email: Eriq.Gardner@THR.com

Twitter: @eriqgardner