I've been considering recently a 4 power version. The four powers would be:
There would be only ONE winner. The Western Allies and the USSR are Allies only in the sense that they do not fight each other and have a common enemy, but only one of them actually wins the game, so they are also rivals.
Summer 1942 start
The US and UK economies have to be handled separately (i.e. you cannot use American money to spawn GIs in England.) Depending on the scale, Germany and Italy may also be separate for balance.
No Capture-the-Capitol rule
USSR-Japan treaty in place until certain conditions are met
Possible winning objectives, based on VCs:
G/I: 4 or 5 of London, Cairo, Moscow, Leningrad, Stalingrad, Cape Town?
US/UK: 4 or 5 of Berlin, Rome, Tokyo, Manilla, Nanking, Paris?
J: 3 or 4 of Delhi, Chungking, Sydney, Hawaii, (Chelyabinsk?)
USSR: 3 or 4 of Berlin, Rome, Belgrade, Kiev (Nanking if Berlin falls?)
Note that the two Allied powers each control a Chinese faction, so USSR can attack Japan through these. The KMT and CCP can also attack each other...
The Soviet player is the easiest to play as he has only one enemy and can throw everything into the Eastern Front early on. But if the Westerners reach Berlin first...
Japan also had one power as an enemy, but has 4 different directions to look to.
UK/US now has to look to both theatres; ignore the Pacific and Japan will stroll to victory. Underfund the European war and the Soviets will get to Berlin before you.
Germany also has to juggle between two fronts.
Overall I think this would tend to prevent the KGF and KRF optimum strategies which are the most common complaint against A&A.
It might even obviate the need for the treaty if it really worked well.
Wondering if anyone has played under similar rules?