Activision Blizzard has added Electronic Arts as a new target in its lawsuit against two former executives responsible for the Call of Duty series. The game publisher also put a price tag of $400 million on its claim.

The amended complaint filed in the Los Angeles Superior Court is the latest salvo in a legal shootout that began when Jason West and Vince Zampella sued Activision for $36 million in March, claiming Activision fired them to avoid paying royalties for their work on the "Call of Duty" franchise.

Activision, owned by France's Vivendi SA, claims EA lured the men away, starting as early as July 2009, despite their having two years left on their contract, in part by using talent agency Creative Artists Agency as an intermediary. It alleges EA dispatched a private jet to Southern California to shuttle West and Zampella to a secret meeting at the home of EA's chief executive John Riccitiello near San Francisco in August 2009.

The two later formed Respawn Entertainment, hiring about 40 employees away from Activision. Respawn said in April it will create games exclusively for release by EA.