Axis & Allies is a tabletop wargame designed in 1981 by Larry Harris and published by Nova Entertainment. The original, now titled Axis & Allies Classic, was republished in 1984 by Milton Bradley. Over the years, Axis & Allies has enjoyed immense popularity, with several new variants being produced and over 2 million copies being printed. Wizards of the Coast plan to release a new version, Axis & Allies: WWI 1914 on 19 March, 2013, which will feature the 8 main powers of World War I.The game has spawned an unofficial digital version known as TripleA.
America Wins the War - To an extent. There is an American faction, but the Axis most certainly is capable of defeating them. Often enough, this is invoked as a strategy by Allied players, who amass a huge invasion force in the US while using the UK and USSR to stall the Axis.
Battleships, in early versions of the game. They cost a lot (to the tune of a single one demanding the Soviets entire economy to produce) and were fairly easy to destroy. Once they got their second hit point and their ability to support naval assaults, though...
Invading the US can definitely be done, but doing so is a logistical nightmare, requires Axis dominance of both Oceans and getting into such a position means the UK and USSR have already been steamrolled.
Boring, but Practical: Russia can be incredibly unfun to play as, with such a bad economy and such a wide stretch of land to cover as Germany pushes east. And yet the Allies team often lives and dies by Russia, the anvil to the United State's hammer.
The British Empire - Can be played. The territories that the Empire controls vary based on what version you are playing. (Versions that feature ANZAC will not have Australia and New Zealand controlled by Britain, etc.)
Earth Is a Battlefield - Quite literally. Territories can be controlled on all continents, with the obvious exception of Antarctica. Especially prevalent in the global versions of the game. (Read: Most of them)
Neutral No Longer - All versions had neutral nations that could be occupied, either by paying some IC cost or fighting the local armies. Later versions made some of these neutral nations pro-Axis (such as Bulgaria or Finland) or pro-Allies (such as Brazil or Yugoslavia), meaning rather than having to fight them during the combat phase to take control a country of the correct side could simply move a unit into that space during its non-combat phase, and the territory (along with its industrial production) and all the local units would fall under its control. If a true neutral (those that don't lean either way at the start, i.e., Spain or Turkey) is attacked, all true neutrals on the board would immediately become pro-whatever-side-didn't-attack (for example, if Italy attacked Switzerland, all true neutrals would become pro-Allies, so Britain could just move a unit into Spain to take control of its IP and 6 infantry there).
You Get Knocked Down, You Get Back Up Again - If a nation loses its capital, it cannot purchase more units or really participate in the war effort to a great extent. However, if the remaining units of that nation, or one of its allies, retakes the capital, they can jump right back in and take the fight to their enemies.
Zerg Rush - Can be done if a player accumulates enough ICPs to build up a large enough military. Also a core aspect of many Soviet strategies, which involve as many infantry and tanks as you can possibly build being flung at the Germans. Just like the real Russian Front.