Call of Duty 4: Modern Warfare is a 2007 first-person shooter developed by Infinity Ward and published by Activision. It is the fourth main installment in the Call of Duty series. The game breaks away from the World War II setting of previous entries and is instead set in modern times. Developed for over two years, Modern Warfare was released in November 2007 for the PlayStation 3, Xbox 360, and Microsoft Windows, and was ported to the Wii as Call of Duty: Modern Warfare – Reflex Edition in 2009.

The story takes place in the year 2011, where a radical leader has executed the president of an unnamed country in the Middle East, and an ultranationalist movement ignites a civil war in Russia. The conflicts are seen from the perspectives of a U.S. Marine Force Recon sergeant and a British SAS operator and are set in various locales, such as the United Kingdom, the Middle East, Azerbaijan, Russia, and 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.