From Hearts of Iron 4 Wiki
Revision as of 02:08, 24 August 2016 by Potski (talk | contribs) (Capitulation & Defeat)
Jump to navigation Jump to search

Land warfare

Main article: Land warfare

Air warfare

Main article: Air warfare

Naval warfare

Main article: Naval warfare

Capitulation & Defeat

Capitulation is a process that occurs during warfare when the percentage of a country's victory points under enemy occupation exceeds the country's national unity. This calculation is not the same as Hearts of Iron III - every province counts at least one point towards the victory point total, named cities count 10x their displayed Victory Point level. You still need to capture the main Victory Point cities, but the large number of unnamed provinces can add up to a significant amount either in their home land or overseas.

When a country capitulates, it will lose all troops in home territories and either retreat to distant colonies or ally states. Furthermore, all core provinces (and provinces contiguous with core provinces) without ally troops occupying them will be lost to the enemy state with the most occupied victory points.

Capitulation does not mean instant defeat for a country. If the country is in a faction, the war will not be over until all major faction members are defeated.

War Participation

War Participation is a measure of a country's contribution to the war effort. War Participation can be accumulated by a country for

  • Bombing Enemy provinces
  • Occupying Enemy provinces
  • Losing Manpower while combating the enemy.

Each action will accumulate score, which is then compared to the overall score of the Alliance to produce a percentage War Participation. This score is also used during peace conferences.

Peace conference

Victors take turns making demands.

When a war has ended, and all enemy nations defeated, a Peace Conference will be launched. During a Peace Conference, victor countries can make demands of the defeated countries, demanding things such as

  • Releasing Nations
  • Releasing Nations with victor's ideology
  • Returning Territory
  • Returning Core Territory
  • Ceding States
  • Changing Ideology

These demands can be made with the points assigned to nations after winning the war.

Volunteers and expeditionary forces

Volunteers and Expeditionary Forces are ways of sending soldiers to Wars, or aiding Allies, without having to be a part of the War.


Sending Volunteers to the Spanish Civil War as Germany

Sending Volunteers is a way to for a country to send divisions to fight in the wars of other countries without joining that war itself. It is a great way to gain Experience in the years before major wars break out and for a country to influence the outcome of a war without becoming diplomatically involved. Volunteers can also be used by a player to field test a division template in combat conditions. Volunteers are controlled, supplied and reinforced by the country that sends them, not the country that receives them. Sending Volunteers increases World Tension.

A nation can only have Volunteers abroad while not at war. The ability to send Volunteers is limited by Ideology and World Tension, where Fascists can do it whenever they like and at the other extreme Democracies are fairly limited. France has an ability to do it earlier.

In order to send Volunteers they must first be formed into an army. They may be assigned a commander, who can earn experience. They are then sent through the Send Volunteers diplomatic action. Once the army arrives, a new army theatre is created for the player and the Volunteer army group is automatically added to it. It takes two weeks for a Volunteer force to travel to the receiving country or to return. They return home if their home nation is at war or the war they were sent to ends. When volunteers return, they bring 95% of their equipment with them. The remainder is lost in transit or remains in the destination country. Volunteer divisions can also be disbanded, which returns the manpower and equipment to the sending country, but requires a new division to be formed and trained to replace the disbanded one.

The number of divisions that can be deployed is 1 division for every 20 active divisions (rounded down, so with 19 or fewer no Volunteers can be sent). I.e. 176 active divisions means 8 divisions where 181 would mean 9 divisions could be deployed as volunteers. Note that a division with only 1 battalion in it counts as much as one that has 25. The minimum of 20 divisions with 1 infantry will enable 1 volunteer division to be sent. The sending country must have at least 30 divisions to send volunteers at all. Added to this is one division per 20 provinces in the destination country.

Expeditionary Forces

Sending Expeditionary Forces is a way to hand over troops to allies in war. It is useful if the player doesn’t want to control them, or if AI wants to fight in a theatre and thinks the receiving player will do a better job. They can be handed over and taken back at any time. AI will often ship them as well if it has convoys available.

Some issues regarding Expeditionary Forces can be clarified in full by testing, while others await guidance from the development team. Testing shows that war score for occupation by an Expeditionary Force goes to the country controlling them, while war score for casualties goes to the home country (the one providing the Expeditionary Force). Destructive testing of expeditionary forces and observation of such forces with depleted equipment indicates that manpower and equipment reinforcements are drawn from the the home country pools. However, there are many players who have attributed manpower drains to expeditionary forces. It may be possible to test (and worthwhile to discover) whether at the time that the home pool runs out these units cease to reinforce or do they instead draw from the host country's pool, which would explain these reported anomalies.

Expeditionary Force divisions can gain experience but their template may not be modified by the receiving country. Players receiving Expeditionary Forces may wish to provide Lend-Lease shipments to the home country of equipment types that it may use to supply the Expeditionary Forces. Some of the home country's equipment may appear in the controller's stockpile, which might possibly relate to the loss of related manpower and salvaging of equipment by the controller.

Some other open topics for investigation and testing are how the army experience generated by the Expeditionary Force in combat or in military exercises is allocated, and confirming the manpower and equipment effects of template changes by the home country.

War goal

Italy selecting a war goal against Switzerland.

A war goal is needed to declare war. A war goal is usually a conquest of a desired state.

Justifying a war goal costs political power, increases world tension and usually takes between 6-9 months to complete. When a country has a war goal, it can start a war against the target country. Countries succeeding in their war goals get an advantage in peace conferences. There are several national focus that will give countries historical war goals. However, ahistorical war goals are also possible, such as Sweden restoring its historical borders.


Besides the national foci, war goal justification will require one or multiple conditions to be met before it can even begin. The conditions will be different depending on the ideology (Communism, Democracy, Fascism or Non-aligned) as well as the faction (Allies, Axis, Commintern, others) and the World TensionWorld Tension level.

Communism icon.

Communists have virtually no restriction on justifying war goals.

Democracy icon.

Democracies are very limited in how they can begin wars, to simulate the influence of popular opinion during the time period. These limitations are lifted if a country becomes fascist or communist.

  • Cannot start a war against another democracy.
  • Cannot justify against a nation that has not increased the world tension.

Communism icon.

If a fascist country already has a war ongoing, they can justify a new wargoal much faster than normal.

Ideological effect

All ideologies have one or multiple effect on the cost of war goal justification or enactment at the peace conference.

Communism icon.

  • Can force government.
  • 70% cost reduction when puppeting other countries.

Democracy icon.

  • Cannot send volunteers.
  • Cannot puppet another country.
  • Cannot occupy a country without war (captured neutral territory will be returned).
  • 25% cost increase of Taking States.
  • 50% cost increase of Annexing country.

Fascism icon.

  • Cannot force government.
  • Cannot occupy a country without war.

Neutrality icon.

  • Cannot force government.
  • Cannot send volunteers.
  • Cannot puppet another country.

Political power cost

It's necessary to spend a certain amount of political power to start justification of a war goal.

The base cost is xx, then the following modifications can apply:

  • -90% When justifying war goal against a major power at war.

Once the justification is ongoing, It will also be necessary to spend 0.2 political power per day on the war goal justification to complete it in the minimum number of days. Any deficiency in political power will stall the war goal justification.

Unique rules

There are a few ideology- and faction-specific rules for war goals.