HOI4 (Hearts of Iron IV): How to Supply Troops (2024)

Hearts of Iron IV, or HOI4, stands as an intricate grand strategy game placing players at the helm of a nation in the tumultuous Second World War era. Beyond shaping the nation’s destiny, players wield authority over their armed forces, mirroring the significance of logistics in history—echoed by General Pershing’s adage that while infantry secures battles, logistics secures wars. In HOI4, this wisdom remains pertinent, as ensuring well-supplied troops can decisively sway individual clashes or entire theaters of conflict. This comprehensive guide delves into the diverse methods of troop supply, unraveling the crucial strategies for maintaining the logistical lifelines that underpin victory in this immersive and historically grounded gaming experience. So, here is how to supply your troops properly in HOI4.

Supplies Mechanics in HOI4 Explained

In Hearts of Iron IV, supplies are not produced but are rather represented by the supply capacity of a logistical hub. There are three levels of supply – Hub Supply, Aerial Supply, and State Supply.

• Hub Supply is the network of railroads, ports, supply hubs, and convoy routes that distribute supplies from the capital all the way to the frontlines.

• Aerial Supply is provided by transport planes solely dedicated to supplying air zone/s.

• State Supply is a fixed level of supply for each state but equally distributed among the units stationed within that state.

In the order of supply, state supply will always be applied first, followed by hub supply second, and aerial supply last. As long as units are being fully supplied on the frontlines, combat effectiveness will remain at its peak, however, should there be any drops in supply, the combat strength of a unit will weaken.

To access the supply map mode, simply press F4 or click on the supply map mode on the map modes. The supply situation in a state is divided into five different colors, each with its own meaning.

• Bright Blue – there is a large amount of supply in the area still available.

• Dark Blue – there is only a small amount of supply in the area still available.

• Purple – there is only a small amount or no available supplies but no debuffs are yet implemented

• Yellow – there is an insufficient amount of supply for the troops in this state but there is enough to provide a partial supply

• Bright Red – there is an insufficient amount of supply for the troops in the area and all units in this state are suffering from supply debuffs

How to Supply Troops in HOI4

To supply troops in HOI4, there are multiple means to do so and as such, we’ll go through them by their supply level mentioned earlier and some alternative methods.

Hub Supply

• Building more supply hubs closer to the frontlines – doing this is the easiest method to boost supply as it will serve as the frontline supply point and give the player a forward supply hub to enable future offensives. Constructing a supply hub will take 20000 in construction costs.

• Increasing the railway connection level connecting the nearest supply hub to the capital – maximizing the level of a railway connection to the capital will increase the number of supplies in that particular supply hub, making it easier to supply a larger amount of troops (provided they are in range).

• Build a port (a lot faster than constructing a supply hub) nearby – the faster option will see a supply point built quickly and can easily provide supplies to nearby armies (provided the seas are well protected from any convoy raiders). Bear in mind that ports only grant 8 maximum supplies if supplied via sea instead of the railway to the capital.

• Increase the level of motorization in a supply hub, port, or army – this option will extend the range of supply hubs as trucks and mechanized vehicles can reach much farther than simple cavalry can.

• Having enough trains on hand – an easy mistake to make is to not have any production of trains done daily, thereby, jeopardizing the supply situation on the frontlines. Armored trains are more expensive than the regular and austerity ones but come with extra armor to protect them against enemy attacks.

• Construct infrastructure in a state – boosting the infrastructure level of a state (especially when it has a supply hub) will reduce the drop-off in supplies from one state to another though bear in mind that fully upgrading infrastructure levels will cost more than just constructing a new supply hub.

• Capturing enemy railways and supply hubs – the most straightforward manner is to simply take the enemy’s supply points during offensives and connect them to your capital. Once a small timer has passed by, the supply point will now work for the benefit of your armies.

State Supply

• Capturing enemy victory points and building infrastructure in occupied states – the greater the victory point of a city, the higher the amount of state supplies it provides. Likewise, having a higher infrastructure level and a greater population will also provide bonuses to the supply that the state provides

Aerial Supply

• Performing Aerial missions – the last of the three supply levels see transport planes taking on aerial supply missions to specific air zones or attached to armies. Doing this will require command power and each plane is capable of providing 0.2 supplies provided full mission efficiency is achieved and there is good weather.

Alternatives

• Disabling Supplies for Allied Forces – in some cases, supply may be hard to provide due to the sheer amount of allied forces stationed alongside your own (which the AI is keen on doing). Selecting a supply hub and disabling allied access to this should boost your supply situation as without supplies, your allies will move their troops elsewhere. Be warned that doing this comes with the caveat that without allied forces boosting your frontlines, the enemy may be keen to launch an offensive.

• Having Special Forces Attack – in the case of special forces, they have a unique mechanic called supply grace which allows them to maintain 2-3 days of full supply despite the state having little to no supplies. This number can be further increased by completing all special forces technologies (as both lines provide supply grace) and unlocking the Amphibious trait for a General.