The story is centered around a fictional near-future conflict involving the United States, the United Kingdom, and Russia, who are fighting against Russian ultranationalists in civil war torn Russia, and rebels that have staged a coup d'état in a small Middle Eastern country. It is told from the perspectives of a United States Marine and a member of the British SAS, and is set in multiple locations, including the Middle East, Azerbaijan, Russia, and Prypiat, Ukraine. The multiplayer portion of the game features various game modes, and contains a leveling system that allows the player to unlock additional weapons, weapon attachments, and camouflage schemes as they advance.[10] The game was in development for two years. It uses a proprietary game engine, and includes features that include true world-dynamic lightning, HDR lighting effects, dynamics shadows, and depth of field.[11]
Call of Duty 4: Modern Warfare received considerable praise and has won numerous awards from gaming websites, including IGN's "Best Xbox 360 Game".[12][13] It was the top-selling game worldwide for 2007, reaching over seven million copies as of January 2008