Legal fight over $22.5m gaming takeover deal
Gaming veteran John Carmack is suing ZeniMax Media for $22.5m (£18.5m) which he claims the company has not paid him.
He alleges the cash should have been handed over as part of the deal that saw ZeniMax take over id Software - the game studio Mr Carmack founded.
In 2009, ZeniMax paid $150m to buy the studio, best-known for making the Doom and Quake series of games.
In response to the lawsuit, ZeniMax said Mr Carmack's claim was "completely without merit".
The lawsuit comes soon after ZeniMax won a $500m legal fight against Oculus - Mr Carmack's employer.
The terms of the id Software takeover rewarded Mr Carmack with a $45m payout, say legal documents seen by news site Tech Crunch.
In 2011, Mr Carmack converted half of that settlement into shares of ZeniMax stock and says he expected the rest to be paid in cash. The legal papers allege that although the shares have been handed over, ZeniMax has not yet paid the remaining half of the settlement.
The documents claim the delay is due to "sour grapes" on ZeniMax's behalf and asks the court to compel the company to pay up.
After the sale of id Software, Mr Carmack stayed on as chief technology officer for 18 months before leaving to join virtual reality headset-maker Oculus in 2013.
In February, Oculus lost a court case against ZeniMax, which claimed the VR firm had stolen its technology. The courts said Oculus owed ZeniMax $500m in damages.
In an email to the Dallas Morning News, ZeniMax dismissed Mr Carmack's claim and said a court had already rejected an earlier attempt by him to get the cash.