Hearts of Iron IV
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A Battle Plan is an important tool that helps players visualize how their divisions will advance, allows the AI to control the player's divisions automatically, and can confer a planning bonus. Plans do not have to be drawn in order to give divisions orders, but are generally recommended as they reduce micromanagement and improve the flow of gameplay.
If desired, different divisions within a single army may be allocated to different battle plans. In this case, players will usually have to manually assign divisions to each front, or they will default to the first front drawn.
An example of a battle plan would be a major invasion of Italy, north of enemy lines, designed to crush an enemy preoccupied with an engagement from the south. The player can set up, and separately activate one or more amphibious landings, paradrops, and attacks by ground forces already facing the enemy, each at the time he thinks best. Some of these plan orders might be set up to be implemented (by the player at the same time, while others may be set up to occur in sequence, in each case activated by the player as needed by shift-clicking only on that specific order to activate it, and with the ability to change that element of the plan or the troops assigned to it before or after activation. This allows different parts of an army to perform separate tasks for the player within an overall strategy, much as army corps performed different missions for WW2 armies. Use of such complex plans is optional, but occasionally very useful when a player has to launch multiple different operations at the same time or by stages.
To make a battle plan for offensive land operations, the player must first define a Front Line – this is the point from which the army group will begin operations. Select the Front Line button or the hotkey z, then click on or draw a line on the map along a national border or the current line between opposing forces to indicate where the army's currently selected divisions will assemble. Then click the Offensive Line button (a line with an arrow) or the hotkey x and draw the front to which the armies should advance from the current Front Line.
Drawing battle plansEdit
How a battle plan is drawn will affect how the AI will execute it. The AI will do what the battle plan tells it to do without question, so a bad plan can have terrible consequences. Here are the tools that the player can use to create a battle plan:
When selecting a naval invasion order, the player will be asked to left-click on a province with naval base as point of departure. There the army will gather for the assault. And right-click on the enemy province(s) to invade.
Naval invasions may be launched from any friendly port that the player has access to. This means that an invasion can be launched on enemy territory from the port of an ally that is not at war with the enemy.
The total number of divisions assigned to naval invasions of a country is limited by its Naval Invasion Capacity. The capacity is determined by the naval technologies of the 'transports' branch. The base value is zero, which means that the technology “Transport Ship” must be researched before divisions may be assigned to a naval invasion.
|1944||+100||Advanced Landing Craft|
The naval invasion order that has more divisions assigned than the Naval Invasion Capacity limits will not take place. The arrow on the map appears but with the text “No divisions 0 Transports”. The assigned divisions keep their ! red exclamation mark which indicates that they have no orders.
Country's invasion capacity is measured in division number, not in their total weight or combat width. Wider and more powerful division templates allow to execute stronger invasions.
Naval invasions require time to prepare before they may be executed. The exact time it will take is dependent on technology and the amount of divisions to be shipped over. With the first level of naval invasion technology, a 1-division invasion will take 7 days and 10-division invasion will take 70 days of planning. Landing Craft technology (1940) halves time required.
The planning will proceed immediately, even while the divisions are still on their way to the departure port.
It is possible to prepare several invasions from different ports in parallel, even to the same target province(s), saving on total preparation time. It is also possible to prepare several invasions to different target provinces from the same port.
In order to ship units over to foreign lands, sufficient convoys are required to do so. The amount of convoys an individual division requires is dependent on its weight; the weight is equivalent with the amount of convoys require to ship over one division. The amount of convoys required is rounded up. Technology may decrease the amount of convoys required for an invasion.
To execute a naval invasion, a country requires more than 50% naval supremacy (also called 'naval superiority' in some tooltips) in all strategic regions in which the divisions will need to traverse the sea en-route to their destination.
Naval supremacy over the region depends on the amount of ships on missions by the opposing sides, with a multiplicative bonus for air superiority. One fleet can simultaneously contribute to naval supremacy in up to 3 regions covered by its mission.
All ship classes contribute the same to the naval supremacy rating, a submarine being equal to a super-heavy battleship.
Ships on hold do not contribute to naval supremacy. Otherwise all mission types contribute equally. Fleets on Patrol mission with Do Not Engage order contribute as well, even though they never engage in any combats.
Maximum possible bonus from air superiority is +100% to the ship amount, making each ship count for two. It is achieved when air superiority is 100% and there are enough planes to cover 100% of the sea region.
Naval supremacy is only required for a short moment to launch the prepared invasion. After that the invasion will proceed even without sufficient supremacy.
Once the invasion has been properly planned, naval supremacy has been attained, and sufficient convoys are gathered, the plan may be activated.
Invasion in transitEdit
Invading divisions travel through the sea province by province on convoys, and can be intercepted by enemy fleets and bombers just like supply and trade convoys. It is recommended to use escorts for the convoys, lest the enemy rally their entire fleet to intercept the invading fleet.
When invaders reach the shores and begin to disembark, the side being invaded gets a notification with an icon and a sound and has a brief moment to rally any defenders.
Invasion speed is improved by technology, and is greatly delayed by attacks on the convoys.
If there are any defenders in the province where the invaders try to land, a land combat starts. As the troops land they need to unload from the ships first and this leaves them vulnerable to enemy fire, so they receive a hefty malus. Marines are special forces troops specifically trained for amphibious assaults, and receive a large bonus to compensate amphibious landing penalty.
Unless invading divisions have captured a port or a city, they might be cut off from supply, and need to achieve these objectives within 72 hours before supplies run out.
A paradrop is an attack by air on enemy territory. A paradrop may only be executed by paratroopers and their support equipment. Divisions with any battalions that cannot be dropped may not be used in a paradrop. Most kinds of line battalions will make a division ineligible for air drops if they are present in the division; see the division designer display on whether the division is para-capable.
A paradrop must start from an airfield with transport planes. Make sure that the number of transport planes is equal to or greater then the weight of the paratroopers. You must have 70% control of all air zones from the airfield to the drop location. If the airfield has planes over the capacity of the airfield the mission will not launch.
As there is aerial supply system in HOI4, a supply source, such as a large city, a port or a connection to the main front should be established as soon as possible in order to avoid the effects of being unsupplied. It is advisable to land paratroopers in an area near a supply source and to quickly assault that source, as supply sources tend to be well guarded. it is also great to use the new aerial supply system from waking the tiger DLC as it will allow paratroops to fight for long and hold the line against the enemy. Dropping atop enemy troops is an attack with hefty penalties and certain destruction if defeated unless the paratroops can retreat to adjacent friendly-controlled territory.
If experiencing problems with paradrops even when you have air superiority in the target zone, there may be another problem. If your target province lies within an air zone whose central node is outside the range of your transport planes, then it can cause an infinite delay and prevent paradrops. What this means is that, in a number of airfields, provinces might technically be in range of your transport planes, but your planes will never arrive at those provinces, because the target air zone's coverage node is outside of their range (or something like that). The Germany-to-Southern-England thing is a particularly obnoxious example, but it happens in a lot of other places too (the Pacific and South America, for example).
Fortunately, you can get around this broken game mechanic by, well, breaking it further. When your para drop order appears on the Air map screen (same place where you assign Air Superiority and Ground Support missions), left-click the order's circular icon (probably looks blank), then right-click reassign your order to an air zone whose central node is closer to your airfield (this will usually, but not always, be the air zone your airfield is located in).
The AI never attempts paradrops.
A paradrop, like a naval invasion, requires at least 70% air superiority in the strategic area the target belongs to. Air superiority is primarily attained by directing fighters to secure air superiority in a region, but (non-naval) bombing and close air support may help as well.
As with convoys for naval invasions, paradrop orders require transport planes in order to be executed. Contrary to other planes in the game, 1 transport plane does not represent 1 plane but rather a group of planes required to transport units.
The amount of transport planes required depends on the weight of the divisions to be transported. Paratroopers battalions weigh 0.5 and paratroop support companies 0.1. One transport plane has a carrying capacity of 2.0, and so could carry a division of 4 para battalions, or 3 para battalions with several support companies. If the air drop order planes total too little carrying capacity for the paratroops assigned, the transports will make several trips to ferry the paratroops, exposing them to more enemy attacks and causing the troops to arrive in separate waves.
Divisions need to be in a province with an airfield with transport planes in order to be able to execute the paradrop.
Front line and offensive lineEdit
A Front Line is the starting point of attacks into enemy territory. A player can either assign a whole country's border as a front line by clicking on the border or a player can assign a part of a country's border as a front line by holding the right mouse button and dragging the mouse over the provinces the player wants to belong to the front line deployment area. The AI will then move all the divisions into the position that the commander assigns to that front line. They are assigned either by having them selected when the front line button is clicked or added later by selecting them and Control-Clicking on that line. A player can also create several unconnected front lines and assign divisions between them, which may be particularly useful for a field marshal who may command an unlimited amount of divisions conducting various operations in different locations around the world. Divisions that are stationed at a front line that borders a non-ally will receive a planning bonus for their pre-attack preparation time. Front lines can only be positioned at a border, and the front line of battle between opposing forces counts as a border for this purpose.
An Offensive Line is a line that a player draws through enemy provinces that contain objectives for the assigned army units to move to and capture. From a front line, or from another offensive line, a player can draw one or several offensive lines or arrows that tell the AI how the player wants the selected plan's divisions to advance from the front line. The width and arc of the offensive line can be adjusted as described on the tooltip. If the mouse cursor is dragged over the offensive line or arrow the game will show the exact visualisation of how the AI will advance the divisions, step for step. ALT for edit mode and TAB to shift the arrow's base can be useful to direct the main effort.
The order to execute battle plans is given with the button above the commander portrait, along with a tooltip that provides information and advice from the staff regarding the battle plan. The AI then executes the battle plan until the troops reach their offensive line which has then become the new front line. If that front line has offensive line orders beyond it then the execute button has to be pressed again to resume the advance from the new front line. Pausing to rest, resupply, refit, regroup, and coordinate further plans was common between phases of a major offensive. This is also a good time to detach troops to consolidate control over occupied territory, which usually involves smaller divisions that specialize in discouraging unrest. The Garrison Area battle plan order is one used in such a situation.
|Available only with the Together for Victory DLC enabled.|
The spearhead order starts from a front line and can be used alongside or instead of the Offensive Line within an army. Unlike the normal battle plan that spreads out to cover its flanks and adjusts to circumstances, spearheads advance in a narrow path one province wide to their objective, exactly as it was when first defined. This makes them suitable for blitzkrieg-style armored penetrations that can capture a specific goal or work with another spearhead pincer to encircle enemy cities or armies in pockets, sealed in a ring of steel by the mobile and regular infantry divisions following behind. Encircled armies can thus be annihilated, as routed divisions which lack friendly territory to retreat to are destroyed.
Spearhead (shortcut 'SHIFT + X') may be used only through territory past the attacking army's front line or territory assigned to a naval invasion (tanks rolling off the landing craft into battle). Spearheads follow the exact paths traced on the map by right-clicking and dragging the mouse through successive provinces. This may enable the attacking forces to plan a path that bypasses forts, cities, or other undesirable terrain in order to maintain their momentum.
The player can draw fall-back lines in controlled territory, and that will tell the AI upon order execution to move and deploy its divisions behind the fallback line in the same manner as with a front line, hold the line against enemy assaults, and counter-attack to restore the position if the line is broken. Unlike front lines, divisions stationed at fallback lines do not receive a planning bonus; however, divisions that are stationed a long time in a province can accumulate an entrenchment bonus while remaining in that position.
Garrison Area assigns the entire army to guard an area rather than a front line. It is mainly useful for divisions on antipartisan duties or to protect against paratroopers. As the divisions are spread out over one or more states rather than concentrated in a position for defense, this posture is ill-suited near the front line. If part of the area is lost to the enemy, then the garrison units will automatically attempt to recover the lost territory.
The garrison command has multiple subsections (see graphic):
- Protect Victory Points
- Guard Ports
- Guard Coast
- Protect Airbases
- Attempt to Lower Resistance
- Guard Forts
The player can choose which of these he wishes to guard and the UI will tell the player how many divisions the AI considers necessary to satisfy the command. The garrison area order triples the limit of units under a commander to 72 without incurring a debuff. Reducing resistance is best accomplished with an army of security divisions. 2-6 Cavalry battalions plus Military Police make effective security divisions, and require only minimum weapons and training.
A very different type of garrison division is a static division intended for positional defense - its purpose is not to do damage but to entrench and hold as long as possible against enemy attack to provide time for relief to arrive. ORG, DEF, and entrenchment are important, as is piercing enemy armor. This division can be trained infantry with basic weapons, Engineers for defense, and a battalion or company of AA guns (which help against air attack, can pierce light armor, and don't need tungsten to make) or AT guns. It will be fighting alone, so combat width is not important.
When a division is at the starting position of an offensive battle plan (i.e. a battle plan containing at least one Offensive Line or Spearhead order) and is neither moving or fighting, it will accumulate a planning bonus at the start of each day, expressed as a percentage, until a maximum planning bonus is reached. This confers greater combat performance for the division.
The max planning bonus for each division (initially capped at 30%), or the rate of daily planning bonus accumulation, can be increased by certain Land doctrine choices.
When a division with a planning bonus is moving or fighting, it will lose some of its planning bonus each day. The planning bonus for a division will decay slowly if the division is being automatically managed by the battle plan AI. If a division is manually commanded by the human player, the planning bonus will decay at a considerably faster rate.
Since achieving the maximum planning bonus will take a number of days, it may be worthwhile to prepare battle plans during peacetime, so that each division will have a full planning bonus upon the outbreak of war.
If the player wishes to minimise the rate of planning bonus decay, it may be helpful to prepare a complex battle plan containing multiple orders. This can enable divisions to achieve their objectives without requiring manual commands from the player. (For an example of this, see Zwirbaum's battle plan tutorial on Youtube.)
Alternatively, the human player can micromanage their divisions, to achieve finer control or the ability to react to changing circumstances. This presents a tradeoff, as planning bonus will be lost more quickly when manual commands are issued.
Manual control and battle plan; support attackEdit
Divisions that belong to a battle plan and receive a manual order will revert back to AI control after implementing the order.
Once combat is joined, the player may select an unengaged division and then Ctrl+right click (or Ctrl+alt+right click) on the combat icon to make the selected division join in a support attack. This allows the division to assist in the attack without automatically advancing the division into the enemy-occupied area upon victory. The battle plan AI may automatically order such a support attack, as well.
Battle plan and alliesEdit
Players can see their allies' battle plans (an option that can be toggled on and off in the lower right corner of the screen). This may help in multiplayer to coordinate with allies and in single player to understand what the AI is doing because AI countries create their own battle plans.