User:KelvSYC/Comparison of Axis and Allies games

There have been several revisions to Axis and Allies since its original release, and there have been various games published with similar rules that follow the same formula. This article seeks to compare these games.

Games used for comparison
Axis and Allies is a board wargame focusing on a simplified simulation of the events of World War II, starting in late 1941.

There are three major revisions of Axis and Allies itself: the Nova Games edition of 1984, the Milton Bradley release in 1986 (which itself has been revised twice, once in 1991 and again with the release of the 1998 video game), and the 2004 release by Avalon Hill. There have also been four spinoffs to Axis and Allies, based on specific theaters of combat: Axis and Allies: Europe, Axis and Allies: Pacific, Axis and Allies: D-Day, Axis and Allies: Battle of the Bulge, and Axis and Allies: Guadalcanal. There is also a miniature wargame in the Axis and Allies series, Axis and Allies Miniatures, which will not be compared here. Although each of the Axis and Allies games were designed by Larry Harris, Harris was only credited in the game packaging for every edition except the Milton Bradley releases.

Throughout this article, the Revised edition refers to the 2004 Avalon Hill release.

Many unofficial expansions by other companies as well as games based on the Axis and Allies rules have been created, many of which based on the 1991 Milton Bradley second edition. Among the most notable are the products of Xeno Games, Table Tactics, and Conquest Gaming. Among the most notable are World at War, Europe at War, both by Xeno Games, and Conquest of the Pacific by Conquest Gaming. Some of these are standalone games with all necessary equipment provided with the game, while others are "expansions" in the sense that parts of an official game are needed.

Players
Each Axis and Allies game had players representing the various world powers in World War II, in which the player attempts to lead their faction to victory. As the name implies, both Axis and Allied powers are well-represented in every Axis and Allies games. Players typically play as one of the four or five factions present in the game. Regardless of how many players are playing, every faction is involved, thus certain players may be forced to take on the roles of two or more factions (for example, a player playing controlling both British and American forces). The manner in which forces are distributed among the players varies from game to game, although no player can play both an Axis power and an Allied power.

There have also been some special exceptions to this arrangement:
 * In Axis and Allies: Pacific, the British player controls one force, but keep two separate income supplies - one each for India and Australia
 * Conversely, in Europe at War, the Italian player controls one income supply but keeps four separate forces - Italy, Romania, Bulgaria, and Hungary.
 * In Operation Barboassa, the German forces are divided into three groups, thus there can be up to three German players.
 * Axis and Allies: Battle of the Bulge is a two-player game, despite three factions being involved - this is as the large majority of the troops are American and only a token amount are British.
 * Similarly, Conquest of the Pacific, despite it being based on the Pacific war, has British-held Australia under American control for the purposes of simplifying the game.

In many of these games, players take their turns in a predetermined order based on the faction they are playing. Europe at War is a notable exception, in which players move based on their income.

Objective
Axis and Allies is a team game, where either the Axis powers are victorious or the Allied powers are victorious. Individual winners can also be named, but are secondary to the main objectives.

Conquest
The Nova Games and Milton Bradley editions require that two opposing capitals be captured. The Milton Bradley edition optional rule known as "Total Victory" additionally stipulates that a faction must also retain control of their own capitals. The main objective of Europe and Pacific is similar to the Total Victory rule, except that, as only one Axis power is featured in these game, the two games only require that one enemy capital be captured. Pacific has the quirk that the British player has two capitals to defend, while the American player, while ostensibly controlling two different forces, only has one.

The Revised Edition uses the concept of Victory Cities to decide the outcome of the game: at the start of the game, each faction has control of six victory cities (scattered in six different territories), and play continues until one side holds an agreed-upon amount -- typically eight for a shorter game and all twelve for a longer one.

D-Day requires that the Allies, within the ten game turns, take control of three key zones on the board. Germany wins in the game if they manage to prevent this from occuring.

Economic Victory
An alternate means to victory in the Nova Games and Milton Bradley versions was the concept of economic victory. Economic victory represents the ability for a power to generate so much income to compell other powers to the negotiating table in place of further casualties. The Nova Games edition allowed for economic victory for both Allied sides, while the Milton Bradley edition only allowed for an Axis economic victory. To gain economic victory, the powers representing one side of the war must have a combined income of more than a certain threshold.

The introduction of Victory Cities in the Revised Edition was partly due to the desire of the game's authors to remove economic victory from the game. Pacific also has a Victory Point system of Japan based on income, but uses a different mechanic.

Equipment
The board is typically a distorted map of the theater in question, with the board being separated into land territories and sea zones. Some games (such as Axis and Allies: D-Day or Operation Barboassa) do not feature naval units, and thus do not use sea zones. Most games use an irregular pattern for its board arrangement, Axis and Allies: Battle of the Bulge being a notable exception, as it is played on a hex grid.

Territories and sea zones may be named on the board or left unnamed - in many games, territories are named for the geographic area they represent. Land territories are also typically colored to represent the power initially in control of the territory, as well as other annotations such as the units initially in the territory, or the income value of the territory. Conquest of the Pacific is unique in that territories are further differentiated by terrain type (mountainous terrain allow for higher defense and disallow amphibious assault, for instance). Few games do not label all of their territories, although many do label all the territories that are of strategic importance. In contrast, few games label sea zones. Axis and Allies: Europe is notable for naming sea zones, while Axis and Allies: Pacific numbered them - a practice that went on to be a feature in the Avalon Hill Revised Edition. Other games, such as Europe at War, label some sea zones and not others, again due to either strategic importance or as a result of the rules. The reason that sea zones are not labeled is perhaps due to the fact that naval units typically begin the game in a coastal sea zone, which are typically associated with one of its neighboring territories. Furthermore, few games have sea zones that generate income for a player. This, of course, may create confusion as to the placement of aircraft (ie. whether they begin the game on land or at sea), which are typically sorted out in the game rules.

Territories and sea zones may produce income for a player occupying it. Conquest of the Pacific also has the unique mechanic of having to own a combination of territories in order for territories to generate income - if the group of territories is split between opposing powers, no income is generated for either faction.

Even if the gameboard is somewhat distorted for the sake of gameplay, territories and sea zones may be too small for all of the units in a given area to fit all of the pieces, leading to congestion. To address this, many gameboards have insets for specific territories and sea zones. Axis and Allies: Pacific employed task force markers for sea zones, where a marker was placed in the sea zones and the units the marker represented would be placed in a special off-board box, while the Revised edition used marshalling circles for a similar purpose, serving both territories and sea zones. Overcrowding on units was addressed differently in Axis and Allies: D-Day, where there were limits to the number of units that may occupy a zone at a time.

Production Charts
Production Charts are provided with every game except the Nova Games edition. As the name implies, there is also another chart that is used to keep track of the income of all players (and, in the case of Pacific, victory points).

In addition, setup charts are given to each player to aid players in creating the initial setup as well as to remind players to the phases of the game and the proper procedures to doing each phase. Because of the fact that much information is repeated between these cards and the fact that many fans consider the board to be too small, avid players typically create larger boards with the initial setup printed on the board itself, so as to make setup charts unnecessary.

D-Day does not use production charts or setup charts: instead, the initial setup is printed on the board -- those in zones are German units, while those in special boxes belong to the Allied players. Each player is also given a reinforcement chart, which is used to determine which units are placed onto the board (either in the reinforcement boxes for the Allied player, or certain zones for the German player) at the end of the turn.

Industrial Production Certificates
With the exception of the tactical games Axis and Allies: D-Day and Axis and Allies: Battle of the Bulge, which use a reinforcement system, there is one central unit of currency in an Axis and Allies games, used by all of the powers. These currency units are generally referred to as 'Industrial Production Certificates.

IPCs are typically collected based on the income generated by territories under the control of the player at a certain phase during the player's turn, and spent to produce new units or, in some games, research and maintenance. They are typically not tradeable between allies unless there is a specific game mechanic, such as lend-lease, allowing this. However, through in-game actions IPCs may be lost or surrendered to opposing forces. It is assumed that there is an infinite supply of IPCs available, so no power is ever denied part or all of its income due to IPC exhaustion.

It is to be noted that although the original Nova Games release of Axis and Allies used IPCs in denominations of 100s, later revisions, and other games using the same mechanic uses IPCs in unit denominations. IPCs are typically represented with paper currency notes, with Europe at War being a notable exception (its expansion, Russia at War, however, does come with a paper currency supply).

IPCs may also play a central part of a victory system, such as the victory point system employed in Axis and Allies: Pacific.

Neutral Territory
In every game except D-Day, some territories start in the control of a certain power. Those that are not in control of any power at the start of the game are neutral territories. In the Nova Games and Milton Bradley versions, players could occupy or fly over neutral territory, but the first player to do so must pay a token sum of 3 IPCs for violating the neutrality of the territory.

The Nova Games edition also had neutral territories that generated income for certain world powers. If neutrality is violated, the player having control of the territory gains the income instead.

Under the Avalon Hill games, neutral territories are strictly impassible by land or air units.

There is no concept of territory ownership in D-Day.

Convoy Zones
Certain sea zones in Europe and Pacific are Allied convoy zones, which provide supplemental income to Allied powers. This income is simply denied to the Allies when they fall under Axis control -- the Axis player does not gain additional income from controlling convoy zones.

The United Kingdom player in Pacific must split income received from British convoys between their Indian supply and Australian supply, while the Soviet convoy in Europe is unique in that it is associated with a land territory -- if the territory falls, so does the convoy, but the two must be retaken separately.

Unit Limits
Each game comes with a limited supply of units, and may also come with a supply of plastic chips, used to represent multiples of a type of unit. There may or may not be rules that limit the number of units that may be placed on the board based on the given supply. In the original Nova Games release of Axis and Allies, players were not allowed to buy additional units of one type if all of that type's pieces were already on the board (for example, a player would be limited to eight infantry units on the board at any given time). The Milton Bradley releases of Axis and Allies limited groups of units to the number of unit figurines (for example, one may have 50 aircraft carriers, they may not be split up into more than two groups, as a player had only two actual carrier units).

Later Axis and Allies games do not limit the number of units that may be on the board by the number of units or chips supplied with the actual game, while games such as Xeno Games' Pacific at War may limit the quantity of some units and not others. The number of figures in each game may thus differ between factions, based on typical usage.

Game mechanics
Axis and Allies games are divided into turns, in which each power in a predetermined order makes their moves. Each power, in turn, must go through a number of different phases during their turn, which are in an order specified in the game. These typically include, in some order, two movement phases, one for combat and one for noncombat purposes, as well as two phases for purchasing and placing units, and a phase for combat itself. Some games may also have phases unique to their game, or have phases that are integrated into the main phases.

Examples of unique phases include the following:
 * Axis and Allies: Pacific has a unique combat air patrol mechanic, which are placed in two different phases
 * Europe at War allows certain units to "break through" and undergo a second combat movement.

One notable game that does not follow this mechanic at all is Axis and Allies: D-Day, where, because of the tactical level of play, each turn is divided into 16 phases, where both Axis and Allied units move simultaneously (some phases affecting only the Axis powers and some affecting only the Allied powers). These 16 phases (or "orders") could be modified through the use of Fortune and Tactics cards, and may be skipped in its entirety.

For a comparison of game mechanics, D-Day will not be taken into consideration unless stated otherwise due to the greatly diverging game mechanics involved.

Purchasing
The purchasing phase is where IPCs are spent, and is typically done at the start of the turn. Units may be purchased so that they may be placed on the board at the end of the turn. Some games may also have a research mechanic, in which IPCs may also be spent for this purpose in this phase. Spending, however, is typically not exclusive to the purchasing phase: invasions of neutral territory, breaking treaties, lend-lease mechanics, and the like may have IPCs spent during other phases.

Europe at War is one notable exception, where purchasing is done at the end of the turn after units purchased in the previous turn are deployed.

Combat Movement
Before combat begins, units must move into combat situations by physically moving them into territories held by opponents. In later editions, as there is the possibility that opposing units start a turn in the same sea zone, disengaging from the enemy is also regarded as combat movement. Except in the case of D-Day, moving into (but not out of) combat situations ends the movement of a particular land or sea unit (except submarines in certain editions).

In the Nova Games edition, combat movement is only conducted for naval and air units -- land units are only loaded during noncombat movement, and attack from an adjacent territory.

Strategic Bombing Raid
Strategic bombing raids are conducted by bombers against enemy Industrial Complexes to take away the IPCs held by opponents. To do so, the bombers make a combat move towards an enemy territory with an Industrial Complex, and, after resolving antiaircraft fire, a die is rolled for each surviving bomber, and the total of the dice is the amount of IPCs that the owner of the territory must forfeit.

Losses of IPCs are typically limited by the number of IPCs that are on hand. In the Nova Games edition, however, if a strategic bombing raid left a player in debt, units would be forced to disband (at the price of the unit) to make up for the difference. The Revised Edition also limits the amount lost in any strategic bombing raid (or any other attack causing IPC loss) to the value of the territory itself.

An optional rule in the Revised Editon (Luftwaffe Dive-Bombers) allows German fighters to also make strategic bombing raids, except that the amount of IPCs that are forfeited is halved.

Strategic bombing raids are not used in D-Day due to the lack of Industrial Complexes and the reinforcement mechanic.

Amphibious Assaults
Amphibious assaults in every game except D-Day are ones in which units are unloaded from transports as part of an attacking group. In the Nova Games edition, amphibious assaults are performed in the same manner as other land combats, except that the attack strength of the units attacking from transports are reduced to 1 on the first round of combat.

In the other versions, there is no distinction between those units that are actually unloaded from transports and those units that support the attack by attacking from land due to the combat movement mechanic -- all land units are unable to retreat, and gain the benefits of amphibious assaults (eg. US Marines in Pacific attack on a 2 regardless of whether they are attacking from land or as being part of the actual landing group).

The Milton Bradley edition also introduced naval bombardment to Axis and Allies, in which battleships supporting the transports could make an attack against land units provided that there was no naval battle prior to the amphibious assult. These battleships could only attack on the first round of combat, and could not be chosen as casualties (the players are specifically instructed to remove the battleships from the battle board after the naval support attack). Europe and Pacific also added the ability for destroyers to make naval bombardment attacks (in the case of Pacific, Japanese destroyers could only perform naval bombardment if they did not unload infantry in the same turn), while the Revised Edition they were an option granted through research. The Revised Edition also allowed Japanese destroyers to both unload and support fire in the same turn (using the Tokyo Express optional rule), as well as make supporting attacks on a 3 or less (instead of its normal 2 or less attack). Casualties of naval bomardment can return fire in the Milton Bradley edition, as well as Europe and Pacific, but cannot in the Revised Edition, where they are considered opening fire casualties.

D-Day, which is itself a game about an amphibious assault, has the reinforcement mechanic that simulates much of the same effects.

Combat Resolution
Combat is performed during the combat phase, in any territory or sea zone in which opposing units are present. During the combat phase, a player will be considered the attacker while another will defend. Except for D-Day, players attack separately and defend together (D-Day ' s turn structure makes it possible for the Allies to attack together). This produces a certain quirk in the game: an allied fighter on an attacking carrier is considered cargo, and is lost if the carrier is also lost.

In D-Day, combat consists of one round of play, while other games require that combat continues until one side is defeated or the attacking side chooses to retreat (a third option is also available to submarines, depending on the game). It is also interesting to note that during each turn in D-Day, the two forces must alternate between attacking and defending in the two combat rounds.

In the Nova Games edition, only one of combat, nuclear attack, and strategic bombing may be performed on any territory in a turn.

Noncombat Movement
After combat is resolved, units not involved in combat may be moved (but not into combat situations). With few exceptions, a unit may not move both in combat and noncombat movement. For air units, they must use their remaining movement points to land on a carrier or friendly territory held at the start of the turn -- any that do not are lost.

Except for the Japanese player with the kamikaze optional rule found in the Nova Games and Revised editions, one cannot intentionally make fighters fly on suicide missions, and even then these fighters are lost during combat. That is, fighters may only be lost in this manner if they intended to land on a carrier (moving into the zone where the fighters lie), and the carrier is lost or retreats as a result of another combat. In Axis and Allies parlance this is known as a "risky mission". Any carriers intending to support risky missions must be declared during Combat Movement so other players are aware of this.

Curiously, noncombat movement is also the only time in which opposing units may move, but only in a special case: if a defending carrier with fighters onboard is lost, any remaining defending fighters may move one zone to an available carrier or territory, and any that cannot do so are also lost.

Units
The most distinctive part of Axis and Allies are the units themselves. Except for the original Nova Games edition, which used cardboard pieces with the unit statistics printed on them, units are represented with plastic figurines in different colors: typically a dark brown for Soviet forces, gray (or in later games, black) for German forces, yellow (red in early editions of Pacific) for Japanese forces, green for American forces, and light brown for British forces. Pacific also used yellow (later red) units for Chinese forces. Industrial Complexes and antiaircraft guns, whose supply is shared by all sides in these games, are white in color.

In the Milton Bradley editions, units, with the exception of infantry, among different factions have identical appearances. The Avalon Hill games extended the notion of having unique infantry pieces for each faction to all units, representing each unit with representations of actual equipment used in the war (eg. the American fighter is the P-38 Lightning, while the German fighter is the Ju-87 Stuka). The units for the most part are functionally identical between the various powers, and with few exceptions, each power had equal abilities to produce units.

Unit costs and strengths have remained the same for the most part across all of the games. The Avalon Hill games, however, added artillery and destroyers that were not present in previous games. Some of the more notable differences in abilities are as follows:
 * Transports in the two earlier editions also allowed unloading units into two different territories during noncombat movement, which is not permitted in the Avalon Hill games.
 * The Avalon Hill games allowed fighters to escort bombers on strategic bombing raids.

Aircraft Carriers
Aircraft carriers allow air units to be transported over the seas. They are good defenders (equal in strength to destroyers), but must rely on its cargo to attack (having only token attack strength). Except in the Nova Games edition, carriers may only carry fighters, and may carry up to a maximum of two aircraft.

Carriers, like other ships, only have two movement points, but in the Revised Edition, American carriers have three movement points by the Fast Carriers optional rule.

In the Nova Games edition, defending bombers are considered cargo when on a carrier: if a defending carrier is lost, so are any bombers on board.

The Milton Bradley edition, Europe, and Pacific prohibit fighters from being deployed on carriers, while the Nova Games edition permits newly-built aircraft to be deployed on carriers (new or existing). The Revised Edition permits fighters, new or existing, to be placed on newly-built carriers (for existing fighters, they must be in the coastal territory from which the carrier is deployed). Under tournament rules, however, to prevent fighters from moving over their flight range in order to land on a carrier, any fighter may be deployed on any carrier as long as the fighter is moved to where the carrier is deployed (instead of the territory next to it -- this in turn prevents allied fighters from boarding aircraft carriers).

Among one of the most confusing rules is in Axis and Allies is regards to carrier movement in the presence of fighters: if a carrier is moved during combat movement, the fighters onboard either move with the carrier and effectively support the carrier's attack, or it makes its own combat movement. Similarly, a fighter landing on the carrier ends the carrier's movement (however, it is permitted to, say, move a plane and a carrier to the location of another plane if both have two movement points remaining). These rules are typically used with rules on fighter movement to ensure that the range of a fighter is not artificially extended by the creative use of carriers to move the planes. Any allied fighters on the carrier is considered cargo: if the carrier is lost, so is the plane.

Antiaircraft Guns
Antiaircraft guns are special units that are effective only against aircraft. They do not participate in ground-based combat, and are not lost as casualties: instead, antiaircraft guns are captured. This is largely owing to the fact that antiaircraft guns are not differentiated by color, and the supply of these units are shared between all players. The only way in which antiaircraft guns are removed from the board is if they are onboard a transport when they are lost.

The Nova Games and Milton Bradley editions restricted antiaircraft guns to one per territory. Because it could be a daunting task to simulatneously move antiaircraft guns around to make room for a new one, the Avalon Hill games permit multiple guns to a territory, but only one such gun is functional at any given time.

In D-Day, German artillery gain the functionality of antiaircraft guns, although their antiaircraft ability is only used twice per turn -- once against fighters and once against bombers.

Artillery
Artillery was first introduced to Europe, ostensibly as a means to encourage attacking with infantry: in combat, each infantry paired with artillery attacked on a 2 instead of a 1. This ability also affected US Marines in Pacific, giving them an attack rating as high as 3 under certain conditions. This infantry attack boost is not present in D-Day, however German artillery do gain the abilities of antiaircraft guns in the game.

Under the Revised Edition's Fortress Europe optional rule, German artillery in territories originally held by Germany defend on a 3 instead of 2.

Blockhouses
Blockhouses are exclusive to D-Day, representing pillboxes among the shores of Normandy. Blockhouses had token defense, but were excellent in making counterattacks.

Certain blockhouses along the northern coast had the ability to fire out to sea, eliminating Allied units that are still in their transports. Conversely, naval bombardment by Allied forces allowed blockhouses to be removed from play. Blockhouses, however, may be rebuilt through the use of fortune cards.

Battleships
Battleships are the single most expensive unit in Axis and Allies, but have unparalleled attack and defense capabilities (being the only unit in the game that both attacked and defended on a roll of 4 or less). Originally the same as other units in the fact that a single hit destroyed the unit, battleships were given additional endurance in the third edition of the Milton Bradley rules (which were only found in the 1998 video game) by requiring two hits in a single combat to sink.

Unofficial spinoffs have further elaborated on this concept, with battleships retaining damage after combat. Damaged battleships could be repaired at the cost of its movement (and perhaps IPCs), and may incur a penalty in attack and defense power (for example, damaged battleships in Conquest of the Pacific had only the strength of destoryers).

Other notable battleship variations include the following:
 * In Conquest of the Pacific, the Japanese player may designate one ship at the beginning of the game as the Yamato, with improved attack and defense, as well as requiring three hits to sink (with attack and defense penalties incurring after the second hit). Once destroyed, it could not be rebuilt.

Bombers
Bombers are airborne specialized attackers, attacking on a roll of 4 or less. However, they provide only token defense. Their specialties lie in the ability to perform strategic bombing raids, and in the Nova Games edition, nuclear attacks.

The third edition of the Milton Bradley edition allowed bombers to transport one infantry. However, bombers may not attack when it is used as a combat movement.

In D-Day, bombers, which are exclusive to Allied forces, are used differently, and are used over three different phases: in the first phase, bombers may enter any zone containing no Allied ground troops and make a targeted attack at a roll of 3 or less. The second phase allows German artillery to make an antiaircraft attack. The third phase simply returns bombers back to the airfield on the board. Both Britain and America have one bomber each, and may only have one bomber at a time. However, if the bomber is lost, a new one may be built through a fortune card. Bombers do not contribute to the limit of eight units to a zone.

Destroyers
Introduced in the Avalon Hill games, destroyers are ships that are designed to negate the powers of submarines. Destroyers also fill the gap between submarines and battleships in attack and defense strength. Destroyers may conduct shore bombardment, although it must be enabled by technology in the Revised Edition. Destroyers conducting shore bombardment do so on a roll of 2 or less in Europe and Pacific, while they do so on 3 or less in the Revised edition.

In Pacific, Japanese destroyers are permitted to transport one infantry as if it was a transport, while it is an optional rule (the Tokyo Express rule) in the Revised Edition.

Fighters
Fighters are the main aerial combat unit in Axis and Allies, having excellent attack and defense value.

In D-Day, fighters operate on a different mechanic, and are exclusive to the Allied forces. Early in each turn, the Allied players may deploy their fighters anywhere on the board, and, if they should surivive enemy antiaircraft fire, proceed to strafe German units: any German unit entering or leaving the fighter's zone (including those entering the board via reinforcement) is attacked once by each patrolling fighter. The fighters are returned to the airfield on the board as the last phase of the turn. Fighters do not participate in ground combat in any way. Britain and America begin with four fighters, and any lost aircraft may be regained through fortune cards. hFighters do not contribute to the limit of eight units to a zone, but a maximum of four fighters may patrol any given zone.

Industrial Complexes
Industrial Complexes are the means to which new units are to be deployed on the map. At the end of each turn, newly-purchased units may be deployed in any territory containing an Industrial Complex held by the player since the start of their turn (or in the case of naval units, sea zones adjacent to these territories). Industrial Complexes are also targets for strategic bombing raids, which take away IPCs from their owner.

Depending on the game, additional Industrial Complexes may also be built. Europe does not allow new complexes to be built, while Pacific only allows the American player to build new complexes. An optional rule in the Milton Bradley editions restricts the ability to place new Industrial Complexes to Axis players. In the Nova Games and Milton Bradley editions, Industrial Complexes may be built in any territory held by the player at the start of their turn, while Pacific and the Revised Edition restricts placement of Industrial Complexes to those having income value.

Once an Industrial Complex is built, it cannot be destroyed, except in the case of an atomic bomb in the Nova Games edition. Soviet Industrial Complexes may also be moved under the Nova Games and Revised editions by the Soviet Mobile Industry ability (this introduces a quirk where Soviet units may be deployed in territories without Industrial Complexes, having moved them during their turn).

However, some versions have restrictions on deploying new units: in the Milton Bradley edition, as well as Pacific, Industrial Complexes held by the player since the start of the game (as well as those that were lost and subsequently recaptured) allow an unlimited number of units to be placed there. However, newly-built or captured Industrial Complexes in these editions, as well as all Industrial Complexes under Europe and the Revised Edition, restrict the number of units that may be placed there to the value of the territory. In the Milton Bradley edition, players may place one unit in territories without value.

The Milton Bradley edition also limits players by restricting placement of naval units in friendly sea zones, allowing players to engage in naval blockades. Other editions do not have this restriction, but the enemy force (on their turn) may engage the new ship (or must in the Nova Games edition) in combat simply by remaining stationary.

D-Day does not use industrial complexes, relying on the reinforcement mechanic to supply players with new units.

Infantry
Infantry form the basic backbone unit of Axis and Allies, and much of the rule changes have been made to reinforce the necessity for infantry (as cheap defenders and potential cannon fodder in attacking forces) while trying to prevent infantry overbuildups. In Pacific, the US Marine was a special form of infantry, receiving an attack bonus for attacking in amphibious assults. The introduction of artillery in the Avalon Hill games also gave a boost to infantry attack whenever infantry were paired with artillery.

Some of the optional rules have also been designed around infantry, largely around free infantry placement or improved infantry abilities:
 * British Home Guard: British infantry stationed in United Kingdom defend on a 3 in the Nova Games edition
 * Atlantic Wall: German infantry defend on a 3 on the first turn in an amphibious assault on any territory initially held by Germany
 * US Marines: The American player in the Nova edition may designate any one group of infantry as Marines, which attack on a 2 in amphibous assaults. This is extended to all American infantry in the Revised Edition, but only on the first round of combat.  However, the infantry do not receive the additional attack strength from artillery support in that round
 * Dug-in Defenders: Japanese infantry in island territories in the Revised Edition defend on a 3
 * Banzai Attack: Japanese infantry attack on a 2 in any all-infantry attack in the Revised Edition
 * Mechanized Infantry: American infantry in the Revised Edition gain the movement and blitz abilities of tanks
 * Russian Winter: Soviet infantry may defend on a 3 for one turn per game in the Revised Edition
 * Soviet Nonagression Treaty: The Soviet infantry receives four infantry the first time Japan invades a territory initially held by the Soviets, in the territory being invaded, in the Revised Edition.
 * French Resistance: Once per game, the British player in the Revised Edition may deploy three infantry in Western Europe when it is under Allied control.
 * Chinese Divisions: Chinese divisions under American command allow one American infantry to be deployed in any one of four Chinese territories per turn in the Revised Edition.

Submarines
In every game except D-Day (where there are no submarines), submarines are special naval units with special powers. One of their primary abilities is the ability to treat sea zones containing enemy fleets as friendly, allowing them to move past enemy naval blockades.

In the Nova Games edition, submarine combat is performed before naval combat (ie. during combat movement), an advantage that is known as a submarine first shot attack. Here, any defending submarines may fire at enemy ships that are passing through their sea zone. First shot attacks are entirely optional, and is the only case in the Nova version where the defenders make the first attack. Units hit by the submarines are immediately removed, and the attackers may return fire with any remaining ships (or fighters aboard aircraft carriers). Attacking submarines may not be chosen as casualties of the first shot attack, nor can defending submarines in the return fire if the ship did not excercise the first shot attack.

Submarine combat was integrated into the main combat proper beginning with the Milton Bradley version, where they gain a different version of a first shot attack (and were given attack strength as a result). In the Milton Bradley edition, attacking submarines fired before other ships, and ships that were hit by submarines could not return fire. This concept, known as opening fire, was extended to defending submarines in the Revised Edition. The introduction of destroyers in the Avalon Hill games also allowed casualties from submarine attacks to return fire, as if they were casualties during the main combat phase.

In all cases, submarines may only attack other sea units, and remain vulnerable to aerial attack. In the Revised Edition, however, air units may only attack submarines when they are in the presence of a friendly destroyer. In Pacific, if a Japanese submarine is hit, but successfully returns fire, then any Allied naval unit (not necessarily those of the attacker) may be chosen as a casualty.

The Milton Bradley version also introduced the ability for submarines to leave a battle early: in the Milton Bradley edition, submarines may withdraw from combat and move from the combat zone in question to an adjacent zone -- either one in which any naval unit came in the case of attacking submarines or to any friendly one for defending submarines. The Avalon Hill games replace this withdrawing ability by submerging, which does not move the submarine, and cannot be used in the presence of enemy destroyers. In any event, attacking submarines may choose to retreat with other units as normal.

There are three optional rules concerning submarines:
 * Kaiten Torpedoes: Certain defending Japanese submarines in the Revised Edition were permitted to hit at a higher attack strength at the cost of the submarine itself.
 * Wolf Pack: German submarines in an attacking force of at least three submarines attack on a 3 or less instead of the standard 2 or less, and do so for the entire duration of combat (ie. even if submarines are taken as casualties so as to leave two or fewer submarines).
 * U-Boat Interdiction: The British and American income in the Revised Edition is cut by one IPC for each German submarine in play.

Tanks
Tanks (or Armor in earlier games) are the main ground offensive force in Axis and Allies, having the greatest attack strength of the three land units. Tanks also had the greatest movement of land units, being able to move two territories instead of one. Due to the improved mobility, tanks (except in the Nova Games edition and D-Day) have the blitz ability, allowing them to attack any unoccupied territory with their first movement and immediately continuing onto a second movement.

The Nova Games edition lacked the blitz solely as land units were only permitted to be moved during noncombat movement, while there was no concept of territory ownership in D-Day. For the games with the blitz ability, however, what is considered unoccupied varied: the Milton Bradley edition permitted tanks to blitz through territories containing only antiaircraft guns or Industrial Complexes, while this would stop the tank in the Avalon Hill games.

Up to the Revised Edition (except in D-Day), tanks defended on a roll of 2 or less -- the same as infantry. Because infantry were cheaper, tanks tended to be used less often, as a large infantry defending force would easily be a match for a small tank force. To promote the use of tanks, the tank defense was upgraded to a roll of 3 or less. In D-Day, Allied tanks defended on a 2 or less, while German tanks defended on a 3 or less.

There are three optional rules concerning tanks in the series:
 * Panzerkorps: In the Nova Games edition, the German player may designate any single tank as the Panzerkorps each turn, which allowed the tank to attack on 4 or less and defend on a 5 or less.
 * Salvage: In the Revised Edition, if the Soviet player successfully defends against an attack consisting of at least one tank on any territory originally held by the Soviets, the Soviet player gains a tank in that territory.
 * Panzerblitz: In the Revised Edition, if a German attacking force destroys all defenders in one turn of combat, any tanks involved gained one movement point, to be used in noncombat movement the same turn.

Transports
Transports are the means to which land units may cross sea zones and attack island groups or distant continents. Transports do not attack and provide token defensive value, necessitating the use of escorts. If a transport is lost, so are its passengers.

Transport capacities vary widely from version to version: the Nova Games edition allows transports to carry any two land units (except Soviet Industrial Complexes, which may not be loaded), while the Milton Bradley edition allows transports to carry either two infantry or one of any other land unit. Europe and Pacific allowed transports to carry two land units as long as they were not both tanks, with the additional provision in Pacific that Chinese infantry cannot be moved onto transports, while the Revised Edition allows transports to carry a single land unit (again, Soviet Industrial Complexes notwithstanding) along with one additional infantry.

In a curious quirk, loading on transports in the Nova Games edition takes one movement point away from the transport -- the transport's movement is unaffected in other games.

In all games, unloading from a transport ends the land unit's movement. Units from the same transport may not be unloaded into different territories in the Avalon Hill games, and in combat movement in the Milton Bradley edition. However, an optional rule in the Revised Edition (Lightning Assault) allows Japanese transports to make two amphibious attacks instead of one per turn (ie. loading and unloading twice in the same movement).

In D-Day, transports are simulated by the reinforcement mechanic, in which each of the five beachheads have a limited transport capacity. Because of the limitation of the amount of Allied units in a given zone, it is entirely possible that a transports may contain units at the end of their turn. Blockhouses may also eliminate units on transports.

Research and Development
Research is a trait of the game that only appears in the main games. Six technologies may be researched in the game, which may be researched by any power. Although the rules differ in how research these done, the technologies grant special abilites on the player with them. Each player performs research separately, and technologies are not traded or given in the game.

Research is a strictly optional rule in the Nova Games edition, and is done identically to the Milton Bradley edition: players may buy research dice for 5 IPCs. The research dice are rolled when all dice purchases are made, and only the ones rolling a 6 are kept. These dice are re-rolled again, and the player gains the technologies corresponding to the numbers rolled on these dice. If a player already has the technology represented by the value of the die, the player is permitted to roll again.

The Revised Edition has a simplified research mechanic, designed to avoid the "grab bag" concept of earlier editions. Here, players must choose a specific technology that they wish to research, and purchase research dice as before. However, when the research dice are rolled, players automatically gain the named technology if the number corresponding to the technology appears on any of the research dice.

Under tournament rules, once a technology is discovered, the effects are applied at the start of the following turn. The rules stated in the various rulebooks allow technologies to be effective the moment it is researched.

Jet Power
Jet power allowed fighter planes to defend on a 5 instead of 4. In the Nova Games edition, fighters are also rendered immune to antiaircraft fire. This provision is also used in tournament play in both the Milton Bradley and Revised editions, although they do not form part of the official rules. In the Milton Bradley edition, Germany begins the game with this technology.

Heavy Bombers
Heavy bombers are a technology introduced in the Milton Bradley edition that allows attacking bombers (whether in combat or strategic bombing raids) to attack with more than one die -- three in the Milton Bradley edition and two in the Revised.

Nuclear attacks
Atomic bombs are found only in the Nova Games edition, in which they posess destructive abilities. Because of their destructive abilities, however, a player may only have one atomic bomb at a time (barring capture of other players' atomic bombs). They are stationary units with no attack or defense strength), although they may be transported between territories and sea zones by bombers. These weapons could be launched in one of two ways:
 * If a player also has rocket technology, they may launch a nuclear attack into any territory or sea zone within two spaces of any antiaircraft gun.
 * Otherwise, they can launch a nuclear attack by using a bomber -- the bomber must make combat movement into the target zone alone, and must survive any antiaircraft fire therein.

Nuclear attacks destroy all units in the territory, and are the only means in which industrial complexes, antiaircraft guns, and other atomic bombs are removed from the board.

Other Technologies
Some technologies such as the Atomic Bomb only appear in one of the editions due to either game balance concerns or the reworking of the game mechanic: the Fifth Column technology in the Nova Games edition, which allowed one free violation of neutrality per turn, was replaced by the Industrial Technology in the Milton Bradley edition, which allowed units to be purchased for one less IPC. This, in turn, was replaced by Combined Bombardment in the Revised Edition, which allows destroyers to partake in naval bombardment.

Many variants employ alternate technologies in place of the six provided with the game -- a popular variant is one that allows bombers to carry infantry in a paratrooper attack.