Each faction is paired against it’s canon enemy (Brotherhood of Steel vs Enclave, Institute vs The Railroad, etc) and players can choose either side to help. The new expansion titled Atomic Bonds allows players to work together to help their chosen faction to rise to power and take control of the wasteland. The wasteland just got a little bit nicer as Fantasy Flight Games ( Arkham Horror, X-Wing, Keyforge) have just announced a co-op expansion for the Fallout board game.