Facebook Inc. Chief Executive Mark Zuckerberg will testify in a Dallas courtroom Tuesday for a lawsuit that could determine whether or not the technology behind the Oculus Rift virtual reality headset had been stolen.

Facebook purchased Oculus VR Inc. in 2014 for an impressive $2 billion, but that same year, game publishing giant ZeniMax Media Inc. filed a lawsuit claiming that the Rift was based on stolen technology. In August, ZeniMax updated its filing to explicitly name Oculus founder Palmer Luckey and Chief Technology Officer John Carmack as defendants in the suit.

According to suit, Carmack contributed to the early development of the Rift when he still worked at ZeniMax subsidiary Id Software, the game studio behind “Doom” and “Quake” that Carmack had co-founded in the 1990s. ZeniMax claims that Carmack collaborated with Luckey under a non-disclosure agreement, which the company says Luckey violated when he created a company to monetize the Rift.

“Carmack was given a copy of the prototype by Luckey, and Carmack and other ZeniMax personnel added numerous improvements to the prototype,” ZeniMax said in its filing. “Together, those ZeniMax employees literally transformed the Rift by adding physical hardware components and developing specialized software for its operation.”

ZeniMax also claims that Carmack violated his own employee agreement when he left Id for Oculus, allegedly bringing ZeniMax’s trade secrets with him.

Oculus: ZeniMax ‘did not have the vision’

Meanwhile, Facebook and Oculus continue to maintain that ZeniMax is in no way responsible for the innovations behind the Rift. In a statement, Oculus belittled ZeniMax as being too shortsighted to have actually developed the VR headset.

“We’re eager to present our case in court,” Oculus said in its statement. “Oculus and its founders have invested a wealth of time and money in VR because we believe it can fundamentally transform the way people interact and communicate. We’re disappointed that another company is using wasteful litigation to attempt to take credit for technology that it did not have the vision, expertise, or patience to build.”

ZeniMax is seeking $2 billion in damages, the same amount that Facebook paid to acquire Oculus, so if its suit is successful, it could deal a serious blow to the social media giant. In addition to Zuckerberg’s testimony Tuesday, Oculus founder Palmer Luckey is expected to take the stand later this week. That will be his first public appearance since he admitted to donating $10,000 to a political organization that created anti-Hillary Clinton ads.

Image courtesy of Mark Zuckerberg via Facebook.com