Zynga is being sued by Agincourt Gaming for patent infringement, Bloomberg reports.
Agincourt filed the lawsuit in a Delaware federal court, citing Zynga's history of imitating other companies' products.
The patents relate to processes for credit card payments and online prize redemption, with Agincourt seeking damages and a court order preventing Zynga from using its practices.
"Agincourt's patents cover the most lucrative aspects of online social gaming – including those comprising the bulk of Zynga's revenues – as they contain the crucial 'link' that allows for global, interactive prize redemption over the Internet," said Bill Carmody, senior partner at Susman Godfrey, the law firm representing Agincourt.
The offending games span the entire Zynga portfolio, including Mafia Wars, FarmVille, CityVille, FrontierVille and Empires & Allies. So far, Zynga has offered no comment on the matter.