The Western Front Armies is the first expansion pack for Company of Heroes 2, and introduces 2 new factions: The US Forces, and the German Oberkommando West. It is a purely multiplayer expansion pack, meaning that it does not add new singleplayer campaign content - For that, Relic released a second, purely singleplayer campaign expansion pack: Ardennes Assault. You do not need the Base Game. This allows a Standalone Multiplayer access, though you cannot play as the other three faction without the Base game.