ZeniMax - the parent company of publisher Bethesda Softworks (itself the parent company of id Software) alleges that Doom co-creator John Carmack stole thousands of files from the company to developer the Oculus Rift.

John Carmack.

That ZeniMax is suing Oculus is nothing new. The two companies have been locking horns since May 2014 when Zeminax alleged that Carmack developed the Oculus Rift with Palmer Luckey using tech obtained through ZeniMax back when Carmack was still with the company. This legal dispute went public shortly after Oculus VR was purchased by Facebook for an astounding $2bn - the timing of which raised some eyebrows.

Now, two years later, the complaint has been amended to accuse Carmack very directly of stealing files, even after his employment was terminated in the summer of 2013 - shortly before he became Oculus' chief technology office on 1st August that year.

"Before leaving ZeniMax, Carmack secretly and illegally copied thousands of documents containing ZeniMax's intellectual property from his computer at ZeniMax to a USB storage device which he wrongfully took with him to Oculus," the amended complaint (obtained via GameInformer) said. "After he had joined Oculus, Carmack returned to ZeniMax's premises and took without permission a customised tool that Carmack and other ZeniMax personnel had developed for work on virtual reality."

The complaint also claims that Carmack joined forces with Oculus founder Palmer Luckey in April 2012, one month before showing off the pair's VR headset at E3 2012 in ZeniMax's meeting room. ZeniMax alleges that prior to E3 2012 the Oculus Rift was "a crude prototype that lacked a head mount, virtual reality-specific software,integrated motion sensors, and other critical features and capabilities needed to create a viable product."

Palmer Luckey.

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

According to ZeniMax, Palmer Luckey is a fraud and the widely circulated origin story of him developing the Rift while a teenager living with his parents is a fabrication.

"Oculus, at [Oculus CEO Brendan] Iribe's direction, disseminated to the press the false and fanciful story that Luckey was the brilliant inventor of VR technology who had developed that technology in his parents' garage," the new document reads.

"In fact, that story was utterly and completely false: Luckey lacked the training, expertise, resources, or know-how to create commercially viable VR technology, his computer programming skills were rudimentary, and he relied on ZeniMax's computer program code and games to demonstrate the prototype Rift. Nevertheless, this fraudulent tale was frequently reported in the media as fact. Luckey increasingly and falsely held himself out to the media and the public as the visionary developer of the Rift's VR Technology, which had actually been developed by ZeniMax without any substantial contribution from Luckey."

ZeniMax further accuses Carmack, Luckey and Iribe of being uncooperative with ZeniMax back when Carmack was still under its employ working on a VR headset.

"Luckey informed Iribe and others about the Non-Disclosure Agreement he had signed which (among other things) confirmed that ZeniMax alone owned the critical VR technology being used by Oculus. During the rest of 2012, Oculus, Luckey, and Iribe became increasingly evasive and uncooperative in discussions with ZeniMax regarding appropriate compensation for its technology and support.

"No resolution of that issue was reached, and indeed Oculus never provided ZeniMax with any compensation whatsoever."

When reached for comment Oculus told Eurogamer "This complaint filed by ZeniMax is one-sided and conveys only ZeniMax's interpretation of the story. We continue to believe this case has no merit, and we will address all of ZeniMax's allegations in court."