Hearts of Iron IV is set during the Second World War. That war was a war of maneuver. Fast, armored divisions breaking through enemy lines to encircle and destroy enemy divisions was the basic strategy during this war, and for HOI4, it is no different. In order to maximize your army’s effectiveness, you should aim to create encirclements and avoid broad, slow-paced offensives like in the First World War. This guide aims to teach you the best way to do that.
In order to create encirclements in HOI4 you need to penetrate the enemy line, breakout from your penetration, envelop the enemy using pincers, and then defend and reduce the created pocket.
*A quick disclaimer; encirclements in HOI4 are notoriously difficult to achieve using the battle planner. Although the battle planner works reasonably well for broad offensives, for encirclements it is advised to use manual control.
Battle plans can and should still be used to get the planning combat bonus, but the player should handle actual control of the divisions.
Picking the right location is the first step when trying to create an encirclement. Ideally, you want to penetrate the enemy line at a weak point. Plains tiles without rivers are ideal for this, as they offer no defensive bonuses to your enemy. Avoid starting a breakthrough against a mountain tile or large river if possible. Remember the basic strategy axiom “attack the enemy where he is weak; avoid him where he is strong.”
To achieve penetration, you will need to use divisions which have a high breakthrough stat. It also helps to use hard, armored units to avoid high casualties when making the penetration. Tanks have a very high breakthrough stat as well as armor which makes them hard. Thus, they are ideally suited for the role of penetration. Some players also like to use divisions with high concentrations of artillery, but personally, I believe tanks are the best here.
When attacking to create a penetration, it is also often necessary to launch ‘pinning’ attacks adjacent to the chosen penetration point. This prevents the enemy from rushing reinforcements there, which would prevent or at least delay your breakthrough attempt.
Here we come to a doctrinal choice between large front and schwerpunkt. Large front doctrine (utilized by the Soviet Union) calls for attacks to be made across a fairly large section of the front (in HOI4 terms say 4-5 tiles). The idea is to confuse the enemy by making him unsure of which attack is the ‘actual’ one. Whichever attack achieves breakthrough first is then used as the focus of the offensive.
Schwerpunkt (utilized by the Germans) calls for maximum offensive power to be directed against a single point (in HOI4 terms 1 tile plus a few pinning attacks on the flanks). The idea here is to identify beforehand the weakest point in the enemy’s defenses and hit it as hard as you can to minimize casualties and the time it takes to achieve a penetration.
Whichever doctrine you go with, you will want to provide your divisions with as much air support as possible to maximize their fighting efficiency. If the enemy has air superiority, your units will fight at reduced efficiency as well as suffer a movement speed penalty, which we will see is vital for the next phase of the battle.
So you have cracked the enemy’s defensive line? Great! But your work has only just begun. Once you have achieved a penetration, you must then breakout. A breakout is a rush to the enemy’s rear using fast, exploitive units.
Speed is the most important attribute here. The faster your exploit divisions are the better. Keep in mind, your opponent will be doing everything they can to contain the penetration or counter-attack so you need to be quick and not get bogged down in combat.
This means that you cannot forget about logistics! Divisions that require fuel but have none will move at a snail’s pace. You must either capture enemy supply hubs in your line of advance or supply your divisions via air supply. (Remember that your air superiority level affects the air supply mission. This is another reason why it is so essential to achieve and maintain!)
Finally, as your units advance you should be ‘leaving a trail of divisions’ in order to defend the corridor that you are creating through enemy territory. If you fail to do this, you run the risk of having your spearhead units being cut of and encircled themselves.
Envelopment is the surrounding of enemy units. Your breakout efforts should have been done in an intelligent way that lead to the envelopment of the enemy. Once the enemy is enveloped, he cannot retreat, reinforce, or resupply his units. This usually leads to their destruction.
There are single and double envelopments. Single envelopments are easier as they only require one ‘pincer’. However to be done, they need an ‘anvil’ to envelop against. The sea, impassable terrain, or a neutral 3rd country border can function as the anvil.
Double envelopments are more difficult to pull off, as they require two pincers. However, they have the benefit of not needing any specific geography to achieve. The pincers act as the anvil for each other.
Choosing the right place for the entire attack here is crucial. You wouldn’t want one of your attack pincers to have to drive through marshes or mountains.
Defense and Reduction
Finally, you have enveloped the enemy. Outstanding! However, you don’t expect him to just write off those enveloped forces and sit on his hands do you? Of course not! He will try to break your envelopment by breaking out of or breaking into the pocket. You must defend your envelopment and seek to reduce it as soon as possible.
For the defense of an envelopment, I like to use motorized or mechanized infantry divisions. They have the speed to keep up with the tanks used during the breakout phase, but unlike armored divisions, they have a high defense stat which allows them to hold a line better.
Using a general with the ‘guerilla fighter’ trait is also helpful as it allows your divisions to entrench faster.
Once your defensive lines around the pocket have stiffened sufficiently, it is time to start reducing the pocket. This is important for two reasons. 1) Your forces are quite vulnerable when spread thinly as when defending an encirclement. 2) There is often a disadvantageous economy of force at play when encircling. (i.e. you might be using 15 divisions to encircle 10, which means your opponent is likely stronger elsewhere on the front.)
When reducing the encirclement, attack the most accessible tiles first. Plains or tiles lightly defended by weak or exhausted units should be your priority. Your goal here is to drive the encircled units into an ever-shrinking space. In game terms, this has the advantage of forcing your opponent into situations where the stacking or encirclement penalty comes into play.
Once the encirclement has been wholly reduced, your work is finished! Enjoy your victory and quickly reorganize your forces for another one!
Encirclements are essential if you are to defeat your opponent while expending minimum casualties and effort. The only alternative is using costly, broad WW1-based offensives, which will lose you the war or at the very least make victory much more expensive than it has to be.