How many copies of Gears of War 3  were sold?
Gears of War: Judgment
According to Cowen and Company the first-month sales of "Gears of War: Judgment" were very poor compared to "Gears of War 3" selling about 425,000 units, around a fifth of the two million "Gears of War 3" managed in September 2011. In the United States, the game was the third best-selling title behind "Bioshock Infinite" and "Tomb Raider". In August 2013 it was revealed that "Gears of War: Judgment" sold just over one million copies.
Gears of War 2
On its release weekend, "Gears of War 2" sold over two million copies, and within two months of release, had sold four million copies. It was the seventh best selling video game of 2009 and received several accolades. The game received similar praise as its predecessor, with the new gameplay and multiplayer modes seen as outstanding additions. It was followed by "Gears of War 3" in 2011.