In AA1, all factories could build unlimited number of units, leading to an exploit, where the the US invades Afghanistan, builds a factory there and churns out units in the heart of Asia. AA2 solved this problem by limiting newly built factories to a number of units each turn to the income value of the area, while the starting factories remained unlimited for the original owners. AAR removed the original/newly built distinction, with all factories being limited. Many Triple A scenarios raise the cost or prohibit builds entirely.