The legal feud between Oculus and ZeniMax isn't quite over yet.
John Carmack, the chief technology officer for Oculus, filed a lawsuit against ZeniMax Media in Dallas federal court on Tuesday, claiming his former employer owes him $22.5 million in unpaid acquisition cash.
The lawsuit (PDF) was filed in the same court where last month a jury decided the Facebook-owned Oculus owed $500 million to ZeniMax for unauthorized copying of technology. ZeniMax's subsidiaries make hit games like Doom, Quake and Fallout.
Carmack was a co-founder of Id Software, a game development studio that revolutionized the first-person shooter with video games Doom and Quake. ZeniMax bought Id Software in 2009, and Carmack left ZeniMax to take the position of Oculus CTO in August 2013.
Carmack's breach of contract lawsuit reveals that ZeniMax paid $150 million for Id Software, of which Carmack would receive $45 million as the majority stockholder. He converted half of the $45 million promissory note into ZeniMax shares in 2011.
Now, as the final installment of payment is coming due, Carmack claims that ZeniMax is refusing to pay and asks the court to compel ZeniMax to pay the other half it owes him.
"Sour grapes is not an affirmative defense to breach of contract," Carmack's complaint says.
ZeniMax on Friday said the latest suit is completely without merit.
"Apparently lacking in remorse, and disregarding the evidence of his many faithless acts and violations of law, Mr. Carmack has decided to try again," a statement read. "We look forward to presenting our response to Mr. Carmack's latest allegations in court."
The long-running legal feud between the two companies began in 2014, when ZeniMax sued Oculus and its founder Palmer Luckey, alleging illegally misappropriating ZeniMax trade secrets relating to virtual reality technology. In February, a jury sided with ZeniMax in that case.
First published March 9, 6:36 p.m. PT.
Update, March 10 at 3:48 p.m.: Adds comment from ZeniMax.
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