The summer turn is the monsoon, in which attack or movement into rough terrain is forbidden. In normal weather Allied units (apart from Chindits or stealthy Australians) must stop in rough or jungle terrain, but Japanese can move freely through. However, after the Japanese seizure of Malaya and Burma in Winter 1941, land movement will probably play little role in the game, until the Soviet invasion of Manchuria in the final turns; the land war in China is usually an ongoing attrition and stalemate.