TripleA
An open-source version of the board game Axis & Allies (thus the TripleA). More properly, a gaming framework that can be used to create any number of games of the A&A ilk. It is run in Java and is thus cross-platform. It’s also in beta — so expect some weird glitches and oddities on occasion.
Based in WWII around 1942, the basic TripleA consists of five players, representing most of the great powers, vying over a map of the world. Taking turns, they attempt to conquer and maintain control of various territories. While historical strategies can be employed — e.g. the Western Allies attempting to clear North Africa, then the “soft-underbelly” of Europe — the nature of the ruleset and map tends to create some peculiar scenarios. A good example of this is using the Japanese armies to drive across eastern Asia toward Europe, attempting to coordinate a double attack on the heart of Russia with the Germans. Familiarity with the war is not technically necessary, but is definitely advantageous. Same goes for knowing about Axis & Allies itself.
The five players, two Axis and three Allies, are (in order of their turns): the Soviet Union, Germany, the United Kingdom, Japan, and the United States. There are variants available that will add Italy and China as separate entities as well. This is a strategic level game and doesn’t get too bogged down in the detail of full-blown wargames — and that is a good distinction to make. This is a semi-complicated boardgame, not a true wargame in the sense of World at War or Third Reich. A few rungs on the ladder above, say, Risk. Which is not to denigrate A&A/TripleA; this is a lot of fun as is.
TripleA can be played locally with multiple people, over a network, or via play-by-email. There is an AI being worked on, but it is not available in the latest stable version (0.6.0.1 as of this writing). On Mac OS X, I noticed some memory issues that cause the game to run slower the longer you play. Work around it by saving (which you can do at any point) and restarting the program.
Another caveat is that TripleA requires Java 1.4, which comes with Tiger, but would have to be installed separately on older systems.
Strategies
There are a ton of different strategies available to both sides (multiplied by the different game variants), but they can be classified into groups. Too much to go into here, but there are some general “grand strategies” to consider.
For the Allies, the first thing to do is to decide on either Kill Germany First (KGF) or Kill Japan First (KJF). Concentrate the majority of your forces, of all three Allies, on one Axis power, while fending off the other. Either strategy will do, but KGF is probably preferable as Germany is more of an immediate threat. Also, do not try to defend everything, everywhere: pick your battles and save your most important territories as much as possible in the beginning until you ramp up production. If you do go for KGF, try to slow down Japan with small moves and delaying tactics while your main concentration is on Germany.