There have been two Infinity Wards. The first invented
Call of Duty;
the second saved it from diminishing returns. In the middle was a cataclysmic event in game development, one that played out in public and left a world-famous studio forever changed.
The origin point of Call of Duty, when you get down to it, was actually Medal of Honor: Allied Assault. While still under the auspices of a company named 2015 Games, the nascent Infinity Ward team established a new paradigm for first-person shooters.