From Entertainment Weekly:

Peter Gallagher has filed suit against Joss Whedon and Lionsgate, claiming the Avengers: Age of Ultron writer took the idea for 2012’s The Cabin in the Woods from his novel.

Gallagher (not the Peter Gallagher who played Seth Cohen’s dad on The O.C.) filed suit in California federal court Monday, saying he believes Whedon, who produced and co-wrote the Cabin in the Woods script, took inspiration from his 2006 book The Little White Trip: A Night in the Pines. The film’s director Drew Goddard and Whedon’s production company Mutant Enemy are also named in the suit.

In the court papers, Gallagher explains what he believes are “striking” similarities between the book and the film, including the names of the lead characters and the cabin, the plot, mood, pace and sequence of events. The suit also points out specific scenes that closely resemble one another.

Gallagher claims he has “lost, and will continue to lose, substantial revenues from the production and sale of the Film,” and is seeking $10 million in damages.

From the book's Amazon description:

They say that killing with a knife is the sex of murder. Two bodies coming together, opening the skin of another, the heat produced and lost by it all. To the real killer, there can be no other way. My friends deserved more of a chance than they were given - victims all do - but they seldom get it.... We had just graduated, and not even a week had grown from that date when our paths were cut short. I watched it happen. Even before the first strike, I saw it all going down. I accept the guilt for the part I played, the times I never spoke up, and the lies that I believed. But like I said before, what happened to us doesn't happen to anyone, so how could I have been expected to act differently. It's not until you actually see the knife go in that you really understand what you're into. I did that. I watched them die, and in the end, with my life one of the few and fleeting, I stepped into his world, a world where the fatal blow is merely a checkmate, and killing is just a game. This is our story, how it used to be and how it all ended up.

And the movie's Amazon description:

A rambunctious group of five college friends steal away for a weekend of debauchery in an isolated country cabin, only to be attacked by horrific supernatural creatures in a night of endless terror and bloodshed. Sound familiar? Just wait. As the teens begin to exhibit standard horror movie behavior, a group of technicians in a control room are scrutinizing, and sometimes even controlling, every move the terrified kids make! With their efforts continually thwarted by the all powerful eye in the sky, do they have any chance of escape?

What do you think? Did Whedon steal this idea or are there enough differences to believe the two plots were thought up separately?