Fobs are forward operating bases that are used on the war map. They can be used as defensive, or offensive support, that assist when defending and attacking bases in the war zone, as long as the fob is deployed. They consist of tank, infantry vehicle, and helicopter. These fobs will produce additional units much like a defensive building will. They come in from the edge of the map based on the general direction the fob was placed vs your base at the time of the attack. They will only come in if your base is sitting next to one on the war zone map and they only work if you are attacked on the war zone map. Sitting next to fobs on the war zone map does not provide extra protection from random pvp attacks. If you are in an alliance the friendly alliance fobs will protect you just like your own fobs.