In a new video interview with GameInformer, Mark Rubin stated that Ghosts was almost called Modern Warfare 4 and was going to have a story about a world nuked after MW3′s events.
The team at Infinity Ward started developing right after Modern Warfare 3 finished. Rubin said each person was given the opportunity to post his ideas for a new game using a note card on the wall. They started off by fixing a plan to make MW4. “Well we were going to stay modern, so we were going to do Modern Warfare 4,” Rubin said, “the idea of staying modern was a key point.”
One of the developers thought about making a world that was nuked following MW3′s events, and making that MW4. One of the cards on the wall said post apocalyptic world, and that idea kept hanging round. Rubin said that one of the ideas was, “What if we really destroyed the world, and what if after Modern Warfare 3 tons of nukes are launched, and the world’s really destroyed; it’s the road or Book of Eli kind of thing.”
But then, because of the whole new engine, whole new idea, and playing in a whole new world, the team decided to make a new game instead. Rubin said, “Lets really go with that theme (post apocalyptic) and make a new Call of Duty.” And from there, the idea of Ghosts came about.