Personalized Media Communications has filed a complaint against Zynga over four of its popular titles, claiming the games use its patented personalisation technology.
"Many years of time and labour went into developing our inventions and securing the patents that permit their practice," PMC founder John C Harvey told Gamasutra.
"It wouldn't be right to sit by and allow them to be infringed."
The four patents in question were filed in 1995 and cover subscriber data, networked data and using it to create personalised output like targeted advertising.
PMC has cited Words with Friends, CityVille and Farmville as using that technology, taking the case to the U.S. District Court for the Eastern District of Texas.
Zynga has yet to comment on the claim.