Battlefield: Bad Company 2 takes place in the present day after the events in Battlefield: Bad Company. The four members of B-Company, better known as Bad Company, Privates Preston Marlowe, Terrence Sweetwater, George Haggard, and Sergeant Samuel Redford are sent behind Russian enemy lines to secure a device related to Aurora. But although they managed to escape Russian soldiers and completed their supposedly final mission, the device turns out to be a fake. Consequently Army General Braidwood assigns them to a special operation of stopping Aurora.

The fairly linear single player campaign puts the player into the shoes of Private Preston Marlowe, sending him off to uncover the mysteries surrounding Aurora in a typical first-person-shooter-fashion. On the side of the other members of Bad Company, the player tries to fulfill the various objectives of the missions while gunning down several dozens enemies using a huge arsenal of real-world military equipment but limited to only carrying two main weapons and a side-arm at the same time. During the course of the game, the player unlocks new weapons by finding them during his missions, granting him the ability to equip them from then on at every supply drop.