Barbarian Invasion is the first expansion for Rome: Total War, which takes the action forward to the period of the decline of the Western Roman Empire. The Rome Total War Gold Edition includes both the original game as well as the Barbarian Invasion expansion pack. The campaign begins in 363 AD and If the player has not achieved the campaign goals in 476, an option to quit or to continue the game is presented. The expansion includes simulation of religious factors.
All of the factions that are playable are playable at the start of the game, whereas in Rome: Total War, only three factions are playable and the other playable factions have to be unlocked by either destroying them or winning the campaign.