F. E. A. R. 3 is a sequel to F. E. A. R. 2: Project Origin and the third installment of the series. New to this game is the ability to play the campaign in either single-player mode or co-op mode. As well as being playable online, co-op is also available offline via split screen. In single-player mode, the player can initially only play as Point Man. However, upon the completion of each level, the player unlocks the ability to play through that level as Paxton Fettel. Level layout, cutscenes, and dialogue are identical irrespective of which character the player is using.

The game takes place nine months after the conclusion of F. E. A. R. 2: Project Origin, with Alma Wade's pregnancy nearing its end. When a resurrected Paxton Fettel rescues Point Man from captivity by Armacham Technology Corporation in a Brazilian prison, the two distrustful brothers head back to Fairport. Point Man plans to save the still-missing Jin Sun-Kwon and prevent Alma giving birth. Fettel, however, has an entirely different motive. Meanwhile, a new threat emerges, one of which even Alma herself is terrified.