The Experiment is a single-player game mode in Resident Evil: Umbrella Corps.
It is a horde based mode that has the player surviving the onslaught of creatures while also completing various tasks. The mode only features 3A7 as its main character and also pre-determines his load-out before each mission. After completing a stage, the player can replay it again, albeit with increased difficulty. The difficulty of progressively increases as the player complete each of them, which is indicated by the number of stars in the mission select menu.
The mode offers its own story involving Abraham Jackson and his subordinate, 3A7, who he sends to various locations to do his biddings.