Axis and Allies Strategy

In typical games of Axis and Allies, victory hinges on Moscow. The US and UK require overwhelming force to attack due to the ease of island defense. This overwhelming force is not available without considerable economic resources, such as all of Eurasia. Therefore, the Axis typically employ a Russia-first strategy.

The game is challenging because each country must balance their resources between a number of theatres:

Rossiya (Russia)
Karelia must be defended to keep the Wehrmacht's supply lines long while preventing the Greater East Asia Co-Prosperity Sphere from becoming too prosperous.
Deutschland (Germany)
Can Moscow be taken with the resources available or is the economic potential of Africa needed first? And how much can be spared to destroy British offensive capability and protect European beachheads?
The Commonwealth (United Kingdom)
Forces must be balanced between the colonies in Africa and India, harassing the Germans, and defensive units on Russian soil.
Nippon (Japan)
The Pacific threat must appear significant enough to keep the Americans from focusing all their power on your ally however fancy boats aren't very helpful in mainland Asia.
The United States
Distant from the action, forces must be committed well in advance to liberating Europe (or at least taking pressure off Russia) or Pacific islands while defending allies.

Standard practices include heavy turnover of infantry and armor on the Eastern Front; meager forces being stretched in Africa and West Asia; someone building industry in South East Asia and everyone fighting over it; and the United States launching transports in every direction. The game generally boils down to the Allies racing to Berlin versus the Axis racing to Moscow and it is generally believed that time is on the Allies side (one guideline I've heard is that the Axis have lost if they don't "shake hands" in Asia by the third turn).

Non-standard practices generally involve decisively controlling out-of-the-way economic or transporation resources early in the game to fuel overwhelming force in the main theatres later. Maybe others (or myself in the future) will add specific strategies to this node.


Axis and Allies Tactics

In Axis and Allies, your country's industrial and theatre focus is dictated by strategy while the implementation of that strategy and collection of assorted tempo points falls under tactics. Without going into any specific strategies, some tactical manuvers that often come in handy:

Waves of Men and Tanks
Through friendly territory, armor moves at twice the speed of infantry, therefore if you want your forces to reach the Front at the same time, build them in alternating turns. This technique is particularly useful for offense on the Eastern Front although groups of just armor are particularly attractive targets.
Amphibious Assault on Egypt
If Africa is a priority to Deutschland then they may wish to take Egypt on the first turn using forces transported from Italy in combination with those from Libya. The landing force must first be ensured victory against the British sub in the Eastern Mediterranean which usually has the side effect of leaving the Gibralter battleship floating.
The Meek Shall Inherit the Earth
In the later stages of the game, seemingly useless units can be very effective at harassment. For example, the tank from Eastern Canada can liberate all of Africa if the British and Deutsch forces have died on each other's swords. Similarly, the transport from India combined with the infantry from Australia can MacArthur most of the Pacific if the Nipponese fleet is gone.
NATO Air Craft
The British can build an aircraft carrier and then have American fighters land on it before Deutschland gets a chance to attack. Once the decision to build it without British planes is made, it can be very difficult to switch, so such a combined unit is only useful for defending Atlantic transports. This sacrifice is often necessary due to the distance to American dockyards and the fact that the British usually can't afford to pay for the whole things themselves by the time they need it.
Retract Before Impact
If you know an enemy will attempt to capture a territory with offensive units, it may be beneficial to withdraw all but a skeleton crew so that the invading hordes will have to defend. Since infantry's effectiveness halves when switching from defense to offense while armor's is only increased by 150%, this is mostly useful only for its effect on air forces and the opponent's psychology.
Reverse Kamikazi
Of similar psychological power but dubious actual usefulness, all the units from India can attack (and usually win) Kwangtung on the first turn thereby splitting the mainland Nipponese forces and being generally annoying.