A theater is a player-defined high-level group of command groups. They are typically, but not necessarily, geographical in scope. Alerts such as being in low supply, and a summary of combat progress, are provided for an entire theater, and reinforcement priority can be set for an entire theater.
Air and sea region names will also appear below the command theaters to provide alerts such as impending invasions, ongoing sea battles, and enemy air superiority.
For example, as Germany, assigning units to Eastern and Western theaters will enable easy evaluation of armies on both fronts. Some players may also wish to use a training theater to exercise Trained units after deployment until they reach the maximum training level with Regular experience and are ready to be reassigned to a combat theater, or a garrison theater to organize partisan suppression and defence of ports and victory points.
To create a new theater, if none exist, simply create a new command group (see below). Otherwise, first select a command group. A "New Theater" button will appear. Clicking this creates a new theater and moves the selected group to it. A selected group can be moved to a different theater by right-clicking on the theater.
Theaters may be named as desired, and players may add as many theaters as they like.
Caution: The theater interface shows only divisions that are assigned to a command group. Unassigned divisions are shown in the armies list.
- Main article: Command group
A command group is a collection of divisions that can be led by a single commander. Each command group is part of a theater, and can be moved to a different theater at will.
Command groups allow divisions to be given orders through the battle plans interface, such as assigning to a front and giving a plan of attack, specifying an area to garrison, or giving a fallback line. The commander of each group in the currently selected theatre (or a vague silhouette if it has no commander) appears at the bottom of the screen. If it has one or more attack plans assigned, this portrait will have a button to activate the plans and a sidebar showing the AI's assessment of the plan's value.
Troops can be transported across water and between two friendly ports. When a division is standing at a port, simply right-click another port to have them attempt to transport themselves there. Transporting troops requires convoys and if the country and its allies do not have naval supremacy over the sea region, they may be intercepted resulting in casualties. If a division is not standing in a port, right clicking on the port province, then shift-clicking on the destination port symbol will allow it to be transported in a single order.
Alternatively a battle planner command like garrison will automatically move a unit across an ocean tile if there is no accessible land path to the target and enough convoys are available to transport the unit.
- Main article: Naval invasion
To launch a naval invasion, the battle planner needs to be used. The Naval Invasion order is the first one on the left. First a naval base is determined as starting point, then the coastal province(s) where the invasion should take place. Naval supremacy is required in all of the sea zones crossed for the invasion. The plan then needs to be prepared for a number of days which is a function of the distance traveled during the invasion and the number of divisions added to the invasion. The shortest invasion preparation in 1936 is 7 days using 1 division across 1 sea tile. The naval technology Transport Ship is required to assign divisions to a naval invasion.
A naval invasion cannot start unless the commander has enough reconnaissance information about the sea zones the divisions will be travelling through. Gathering this information requires fleets to be assigned to missions (other than Hold) in those zones, or air wings to be assigned to missions in the corresponding air zones.
There is a limit to the number of divisions that a single country may assign to naval invasions at one time. With the basic Transport Ship technology only 10 divisions can plan an invasion at once; with Landing Craft this increases to 50. Multiple invasion plans can be set up from a single command group; each plan must start from a different port.
An army can also move into friendly territory using an invasion, but it is more efficient to simply use port to port movement as described above.
- Maximum speed. The division travels at the speed of its slowest combat battalion. Support battalions are not counted in this calculation; they are assumed to have the same mobility as the rest of the division.
- HP. "HP" is an abbreviation for "hit points." HP represents how many hits or damage a unit can take before it is destroyed. HP was known as "strength" in previous games. Battalions of Mechanized Infantry have 30 HP; Cavalry, Infantry, and Motorized Infantry have 25 HP; Paratroopers 22 HP; Mountain Infantry and Marines 20 HP; Tanks 2 HP; and line artillery of all kinds have 0.6 HP. Among support elements, Recon, Engineers, Logistics and Field Hospitals have 2 HP; Military Police, Maintenance and Signal units have 1 HP; and Support Artillery, Anti-Tank, and Anti-Air have 0.2 HP. When a division takes damage to its HP, the combat stats are reduced proportionally; for example, a unit at half of its maximum HP can only use half of the maximum possible attacks or defenses in combat. What is obvious from these numbers is that tanks and artillery are relatively fragile when it comes to absorbing damage, and it is high-manpower battalions such as infantry of various kinds that enable divisions to take serious damage and continue fighting until their organization is gone.
- Organization. Organization indicates the readiness of a unit to perform combat. A unit without organization cannot operate as it is supposed to, and such unit cannot stay in combat or move properly. The organization of a division is the average of the organization of the included battalions. See also Land units#Organization. Infantry have much higher organization than other battalion types, so it is generally a good idea to mix in some infantry (typically motorized or mechanized) with these harder divisions.
- Recovery rate. Known as "morale" in previous games. The speed at which the division regains organization: hourly increase in organization when the unit is not in combat.
- Reconnaissance. High reconnaissance increases the chances of a unit's side in a battle picking a combat tactic for the current day of fighting that better counters the enemy's chosen tactic.
- Suppression. Ability to suppress local resistance.
- Weight. How much the unit weighs. Affects the number of transport planes or convoys the unit needs.
- Supply use. How many supplies the unit uses per day.
- Reliability. Reliability reduces the chance of breakdowns and accidents (i.e. attrition due to environment, poor supply, or exercising). Reliability can be increased by Maintenance (support) battalions.
- Trickleback. Trickleback represents the proportion of combat casualties that are saved and returned to manpower pool. This is provided by Field Hospital (support) companies.
- Exp. loss. How much experience is lost when the unit takes casualties.
- Soft attack. Represents the ability of a unit to attack soft targets, that is, targets without armor or with very little armor, such as infantry. In combat this stat gives the number of attacks the unit can make against a target with low hardness.
- Hard attack. Represents the ability of a unit to attack hard targets, that is, armored targets, such as tanks. In combat this stat gives the number of attacks the unit can make against a target with high hardness.
- Air attack. Represents the ability of a unit to attack air targets, how much the unit can do damage against airplanes.
- Defense. Known as "defensiveness" in previous games. Represents the number of defenses the unit has when defending, that is, how many attacks it can avoid. When unit has no defenses left, it is more probable that the unit is hit when in combat and can not hold the defense as well.
- Breakthrough. Known as "toughness" in previous games. Represents the number of defenses the unit has when attacking, that is, how many of the defender's attacks it can avoid. When unit has no defenses left, it is more probable that the unit is hit when in combat and cannot keep the offensive going as well.
- Armor. Representing the armor of a unit, if the armor value is higher than enemy's piercing value, the unit will receive fewer attacks from the enemy. Higher armor than the enemy's pierce will also increase the number of unit attacks in combat and change the organization damage dice roll per attack from 1d4 to 1d6, as it can move around the battlefield more freely without getting pinned or damaged.
- Piercing. Represents the ability of a unit to pierce armor. If the value is higher than enemy's armor value, the unit suffers no penalty to its attacks.
- Initiative. Higher initiative makes the unit more likely to join a battle from reserves and speeds up out-of-combat reinforcement and battle planning.
- Entrenchment. Represents the ability of a unit to build defensive structures and entrench before an attack.
- Combat width. Represents the size of the fighting unit. In order to fit in battle, the unit needs to fit into the provided combat width of the battle field. Different unit types increase the designed width by a different amount: For example, infantry and armored battalions use 2 width, artillery battalions use 3 width, and anti-tank and anti-air battalions use 1 width. Support battalions do not increase the combat width of a division. The Mass Assault doctrine tree has options that reduce the combat width of infantry battalions, allowing more to be fielded in each battle. The Field Marshal Offensive Doctrine trait reduces combat width when on the attack.
- Hardness. Represents how large proportion of the division is made up from units which are armored and protected. Unit with high hardness will suffer more hard attacks and fewer soft attacks. Unit with low hardness will suffer more soft attacks and fewer hard attacks.
- Attrition. Gives chance of equipment loss every day.
- Additionally Reconnaissance and Weight are listed as Misc stats in Unit Details screen. See Base stats above for explanation of these.
- Main article: Combat tactics
Combat tactics are chosen at the start of combat and changed every 24 hours. Reconnaissance stat affects the selection of the combat tactic where higher stat increases the chances to counter the tactic chosen by the enemy.
Combat is resolved in one hour turns, where both the attacking and defending divisions each randomly choose an opposing division to fight against this turn. In the following we refer to as the "attacker" the side who is on the offensive and initiated the combat and as "defender" the side which was attacked. A specific attacking and defending unit then depends on the combat phase and can refer to unit on either side.
The combat widths of each division in a battle are added together to determine how many of those divisions will fit into the width of the frontline and fight. The available width of the combat is increased when attacks on the province come from multiple directions, so tactical flanking is needed to leverage a numerical advantage if the battlefield width is a limiting factor. Width is also affected by certain combat tactics. Base battlefield width for combat is 80, where additional directions bring 40 extra per direction.
The combat width of a division is the sum of the widths of the battalions it contains. Infantry battalions (including motorised, mechanized and special forces) mostly have a combat width of 2, while armoured battalions have a width of 3. Support companies occupy no combat width. The Vast Offensives and Human Wave Offensive technologies from mutually exclusive branches of the Mass Assault doctrine tree reduce the width of ordinary infantry battalions by 0.4, meaning 25% more infantry battalions can fit in the same infantry frontage.
Divisions that do not fit on the frontline at the start of combat end up in reserves and will have a chance to join combat every hour as long as there is room. The chance to join is greatly affected by doctrine tech, or by having a signal company attached to the division, and is important to leverage a lot of units in a single location, because if the frontline falls all divisions on the same side are forced to retreat regardless of their own organization, meaning all reserves will have contributed nothing to the combat.
Soft attacks and Hard attacks give the number of attacks against a defending unit. The Hardness stat of the defending unit determines the proportion of soft and hard attacks the unit receives: For example, unit with 100% Hardness receives all Hard attacks and none of the Soft attacks and unit with 25% Hardness would receive 25% of the Hard attacks and 75% of the Soft attacks.
If the attacking unit has lower piercing value when compared to defenders armor value, only half of the attacks are used.
The number of attacks is compared to number of defenses of the defending unit before calculating the possible damage, see following section on Damage dealing.
The attacker's Breakthrough values are used to determine how many defenses each of the attackers' units has. This is compared to the defenders' units hard and soft attacks to evaluate damage done to the attackers' units.
The defender's Defense values are used to determine how many defenses each of the defenders' units has. This is compared to attackers' units hard and soft attacks to evaluate the damage done to the defenders' units.
Each attack has the potential to be a hit or miss, where hits would cause HP and organization damage to the enemy unit. After each attack, the defending unit removes one defense (if it has some left) and the actual chance to hit depends on if the defender has defenses left or not. The base chance to avoid hit when unit has defenses left is 90%. It the defending unit has exhausted all of its defenses, the chance to avoid hits drops to 60%.
The amount of possible damage done is random, where a "dice" is used to randomly choose the amount of damage done. For HP damage the size of the dice is 2 and for organization damage it is 4. The exact amount of damage done to HP and organization is calculated by multiplying the obtained random integers by modifiers before applying the damage to the units.
When armored units are in combat against targets with lower piercing, the organization dice size is increased to 6 representing the ability of the armored unit to deal more damage.
The damage done to unit's HP reduces the attack and defense stats.
The following factors modify the number of attacks and/or defenses a unit has in combat (list is not exhaustive):
- Terrain: base penalties for attacker -20% in a forest, -30% in hills, -60% in mountains, further modified by division composition (tanks, mountaineers etc)
- River crossing: penalty of -30% or -60% for attacker attack and breakthrough depending on the river size
- Night: penalty of -50% for attacks of both sides
- Fort: penalty for attacker attack and breakthrough of -15% per fort level
- Encirclement: penalty for defender -30%
- Enemy air superiority: penalty for defender defense or attacker breakthrough
- Low supply: scaling penalties up to -33% at no supply
- Exceeding combat width penalty: divisions in active combat can slightly exceed allowed combat width with a small penalty to offset this.
- Stacking penalty for having too many divisions (more than 8 plus 4 if attacking from multiple sides) in combat
- In multiple combats: -50% for a division that is attacked from a different direction while already attacking
- Paradrop penalty
- Amphibious penalty
- Encirclement penalty
- Commander skill, +5% per skill point for both attack and defense
- Planning bonus, the base maximum is +50% which can be further improved by a doctrine to +110%
- Entrenchment: +2% per each point built. Maximum achievable: 5 base + 11 engineer IV + 10 doctrine = +52%
- Air support: bonus to attack and defense (in addition to direct damage support planes do)
- Country bonus
- Division experience: -25% for green, 0 for trained, +25% for regular, +50% for seasoned and +75% for veteran
- Combat tactics
- Decryption advantage: +2.5% per tech level difference. If multiple countries participate in combat, highest decryption is compared to lowest encryption
All positive factors stack with each other multiplicatevely, so it is possible to reach very high values in a very good tactical situation.
- experience +75%
- entrenchment +40%
- terrain +20%
- country +40%
- commander skill +35%
Multiplied together this gives your unit +556% to base stats (1.75*1.4*1.2*1.4*1.35=5.56)
It is not clear how negative modifiers stack as it is possible to attack even into Maginot line with -150% fort penalty and still do a little bit of damage. One possibility is that being attacked from multiple directions simultaneously and fort penalties are added together prior to being applied. I.e. SA = (base stats)(bonus 1)(bonus 2)...(50%*number of attack directions beyond the first - 15%*fort level). Game evidence suggests this may be the case as Germany attacking the tip of the Maginot Line can be attacked by up to 5 provinces and the attack values can be seen to stay at 0 until more than 3 directions are added.
At the end of the combat, a check is made how many points of damage ("hits") against its hit points (HP) the unit has taken and unit's equipment is reduced proportionally to the losses. Modifier EQUIPMENT_COMBAT_LOSS_FACTOR in defines.lua is used, and it is 70% by default.