In the suit, which was filed in Los Angeles Superior Court Thursday, Eric Ryder claims that he entered into an agreement with Cameron's production company, Lightstorm Entertainment, to develop a movie based on his story "KRZ 2068."
Read the full lawsuit here.
According to the suit, the project was envisioned as "an environmentally themed 3-D epic about a corporation's colonization and plundering of a distant moon's lush and wondrous natural setting."
Also read: James Cameron: "Yes, Avatar Is Political"
After working on the project for nearly two years, Ryder alleges, Lightstorm put the kibosh on it, explaining that "no one would be interested in an environmentally themed science fiction feature film."
Shortly after, the suit says, Lightstorm began work on "Avatar," which Ryder says, "liberally and substantially uses material that fell within the LEI-Ryder agreement."
According to the suit, Ryder's story involved a protagonist who's sent to the moon of a distant planet by an Earth-based mining corporation; moreover, the details of the project called for 3-D effects to "infuse the story."
And since, according to the suit, Ryder's agreement with Lightstorm stipulated that material from the project wouldn't be used without Ryder "sharing in the commercial receipts and the writer or producer credits," he wants to get paid from the mega-successful "Avatar."
Ryder claims that he was told that Cameron alone wrote "Avatar," and that he had prepared a "scriptment" for the project before Ryder and Lightstorm entered the agreement. Ryder says that's untrue — and says that his story was circulated to the bigwigs at Lightstorm, including Cameron.
Claiming breach of implied contract, fraud and deceit, negligent misrepresentation and other infractions, Ryder is seeking unspecified contract damages, tort damages, punitive damages and that he be awarded the profits "that defendants obtained from their wrongful acts."
Given the billions of dollars that "Avatar" pulled in worldwide, that could be pretty substantial.
Cameron's attorney and Lightstorm did not immediately respond to TheWrap's request for comment.
Pamela Chelin contributed to this report.