Activision firing Call of Duty creators

During March of 2010, a dispute occurred between Call of Duty creator/development studio Infinity Ward and it's publisher Activision, it all started when Activision fired Infinity Ward co-founders and creators of Call of Duty series, Jason West and Vince Zampella, over unsettled royalties. The conflict would later evolve to legal battles with many Infinity Ward members leaving over the firings of West and Zampella. With Infinity Ward losing many important members this would badly impact their development on new Call of Duty games as this would explain why Infinity Ward's next games Call of Duty: Ghosts and Call of Duty: Infinite Warfare are regarded as the weakest Call of Duty games and more importantly many people believe that this controversy was just the beginning of Call of Duty's downfall.

2010 employee firings/departures and the aftermath
Following the launch of Call of Duty: Modern Warfare 2, rumors spread across the Internet that there was a dispute between Infinity Ward and Activision. Infinity Ward co-founders West and Zampella felt that they were, despite massive success of Modern Warfare 2, being royally underpaid by Activision and they wanted to start a new project not within the Call of Duty series, rather than letting Infinity Ward co-founders negotiate new contracts Activision on March 1, 2010 fired them for "breaches of contract and insubordination". In response to the firing, West and Zampella filled a lawsuit against Activision on March 4, 2010 over "substantial royalty payments" that Activision failed to pay them in the weeks leading up to their firing.

Following West and Zampella's firings, nearly half of the remaining Infinity Ward employees resigned. Throughout April and May 2010, 46 employees, among them lead designers and programmers who worked on Modern Warfare 2, abruptly left Infinity Ward. Vivendi chairman and CEO Jean-Bernard Lévy stated that Infinity Ward's ex-employees were replaced with new ones and are fully reconstructed. Furthermore, the executive stated that there will be three studios working on the Call of Duty franchise including that newly formed studio Sledgehammer Games who will be now part of the Call of Duty development cycle.

Due to Modern Warfare 3 being on the way and with several employees of Infinity Ward have left, Activision requested that Sledgehammer Games stop work on the new Call of Duty game and collaborate with Infinity Ward instead.

After the departure, West and Zampella along with several Infinity Ward ex-employees partnered with the publisher Electronic Arts and formed a new development studio Respawn Entertainment in which later the studio would be well-known for the Titanfall series.

Lawsuit
Following the controversy, Jason West and Vince Zampella along with the current/former employees of Infinity Ward filled a lawsuit against Activision over unsettled royalties, which they did not receive for the sales of Call of Duty: Modern Warfare 2. Activision also sued West and Zampella along with Electronic Arts for $400 million, for certain conspiracies which aimed to detriment Modern Warfare 2. West and Zampella were accused of helping EA with the development of rival game Battlefield: Bad Company 2, which would count as a breach of their contracts with Activision. Eventually, West and Zampella added fraud charges against Activision in their counter lawsuit. As of June 2012, Activision settled all lawsuits involving former IW developers including West and Zampella.