Call of Duty Online is a free-to-play shooter that was released in mainland China. It is based in the Modern Warfare universe and tells a story created by taking pieces of the existing stories of the Modern Warfare games and weaving the parts together in an attempt to create a (mostly) intelligible story.
The multiplayer will be fueled by microtransactions. Players will be able to purchase and "personalize" equipment, including weapons and perks. The game features weapons, maps,and modes from Call of Duty 4 and Call of Duty: Modern Warfare 2, as well as a cooperative players-vs-AI mode based directly on the Zombies mode introduced in Call of Duty: World at War and continued in subsequent Treyarch-developed games, albeit with the zombies replaced with zombie-like "robots", as Chinese culture is not as fond of the living dead as Western culture.
The game went into open beta in January of 2015.