How To Design Ships In Hearts Of Iron 4

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Every Ship Type

Know Your Ship Stats

How To Design Ships

Hearts Of Iron 4 has an intricate naval combat system that adds depth and complexity to the game's arms race. Several key nations - notably the United Kingdom, United States, Japan, and Italy - rely on their navies to project power and keep enemy troops from their shores. The Pacific, the Mediterranean, and the English Channel are all key naval theaters that you'll need to control on your path to victory.

This guide explores the different ship types and their roles, as well as information on what to prioritize when designing your navy. From the North Sea to Midway, if you're looking to improve your naval game, you've come to the right place!

Every Ship Type

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Ships are broadly divided into three categories; capital ships, large and imposing vessels that do the bulk of the fighting in major engagements; screen ships that interfere with enemy operations and escort the capital ships; and submarines, which operate below the surface independently or as support for a fleet.

Ship Type	Code	Role	Notes
Submarine	SS	Raiding convoys and unescorted capital ships, supporting friendly fleets in combat.	Capable of unleashing devastating torpedo attacks if undetected. Slow-moving but hard to detect. Vulnerable to depth charges.
Destroyer	DD	Escorting convoys and larger ships.	Quick and cheap to build. Versatile. Pre-equipped with depth charges, making them good sub hunters.
Cruiser	CL/CA	Can be designated light or heavy to fill a screen or capital ship role. Light cruisers are best for scouting and sinking destroyers. Heavy cruisers provide firepower for a lower cost than battleships.	A good alternative option for countries that lack the capacity for battleships and carriers. An unchallenged heavy cruiser will easily sink screens but is no match for a battleship.
Battlecruiser	BC	Battleship hull with cruiser armaments.	Larger and more durable than a heavy cruiser. Faster and cheaper than a battleship.
Battleship	BB/SBB	Main battle-line vessel. Heavy armor and large damage output. Super-heavy battleships are extremely powerful and only the mightiest nations can expect to produce one.	Slow and expensive to build. Vulnerable to ambush is unescorted.
Carrier	CV	Allows deployment of naval aircraft to support land and sea engagements or to bomb enemy assets. Allows naval and air supremacy over a wide area if unchallenged.	Large and expensive. Planes must be researched and built separately. Easily sunk if alone - must be escorted.

Know Your Ship Stats

Ships have several stats, some of which are unique to specific ship types. Here's what they all mean:

Base Stats

Stat	Effect
Maximum Speed	Determines how quickly a ship can move from one place to another on the map. A fleet will move at the speed of its slowest ship. Faster ships are harder to hit and have an easier time pursuing and evading enemy ships.
Maximum Range	The maximum distance a ship can travel from the nearest friendly port. Building naval bases and negotiating treaties with your neighbors can extend your reach at sea.
Organization	A ship's "action points". Moving and fighting reduce Organization while remaining stationary out of combat causes it to slowly recover. A ship with 0 Organization cannot move except to retreat, which it will automatically do if engaged.
HP	The amount of damage a ship can take before being sunk.
Reliability	Reduces the likelihood that the ship will suffer a critical hit when attacked. Reduces damage taken from attrition due to bad weather or lack of supplies.
Supply Use	The amount of Supply the ship requires to operate on a day-to-day basis. Ships not receiving sufficient Supply for any reason will suffer attrition, taking damage until the problem is resolved.
Deck Size	Only applicable to ships that can launch airplanes. The number of planes that can be stationed onboard the carrier without suffering overcrowding penalties.

Combat Stats

Stat	Effect
Light / Heavy Attack	The amount of damage the ship deals per combat hour, based on the size of the target. Light Attack is used against screen ships. Heavy Attack is used against capital ships.
Light / Heavy Piercing	Compared with the target's Armor to modify the attack result. Light Piercing is used against screen ships. Heavy Piercing is used against capital ships. If Piercing exceeds the target's Armor, the chance of dealing a critical hit increases.
Torpedo Attack	The amount of damage dealt by the ship's torpedoes. Torpedoes ignore Armor, making them dangerous against battleships.
Depth Charges	The ability of surface ships to damage submarines.
Armor	Reduces incoming damage so long as the attacking ship's Piercing is equal to or less than the Armor value. The greater the margin by which Armor exceeds Piercing, the greater the reduction in damage.
Anti-Air	The ship's ability to damage aircraft. Docked ships can use their Anti-Air capabilities against planes attacking their port.

Miscellaneous Stats

Stat	Effect
Fuel Usage	The amount of Fuel the ship consumes per day. The number shown in the ship's stats indicates its Fuel Usage during routine maneuvers (i.e. idle at sea). While the ship is training, in combat, or carrying out a mission, its Fuel Usage increases to 2.4 times the indicated amount.
Surface Visibility / Detection	The ease with which enemy vessels can detect the ship. Opposing ships in the same region will check their Surface Detection against their enemy's Surface Visibility. Once a fleet is successfully detected, it becomes visible to the enemy player. Depending on their current orders, a fleet will either pursue, evade, or ignore a detected fleet.
Submarine Visibility	Works the same way as Surface Detection and Visibility, (see above) but exclusively for submarines.
Minelaying	The number of mines the ship can put into the sea per hour when assigned to do so. Enemy ships in a region with mines are at risk of taking severe damage - the more mines, the greater the risk. A sea zone can have up to 1,000 mines present at one time.
Minesweeping	The number of enemy mines the ship can clear from a sea zone per hour when assigned to do so. Sending in ships to sweep for mines ahead of a major fleet movement can avert disaster.

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How To Design Ships

Once you've researched hull types parts, you can design new ship models in the Ship Designer. This allows you to upgrade existing patterns or to create variants that fill specialized roles. Most components have a tradeoff - increasing one stat will decrease another. The number and quality of a ship's components will determine its overall capabilities.

Below you can check a table with all the component types, their benefits, and drawbacks.

Component Type	Benefits	Drawbacks
Engine	Increases ship's Maximum Speed.	Decreases overall Reliability. Increases Fuel Usage. Advanced Submarine Engines Increase Visibility.
Battery	Increases Attack based on Battery type (Light or Heavy). Cruiser Batteries increase HP.	Reduces ship's Maximum Speed. Heavy Cruiser Batteries increase Surface Visibility.
Anti-Air Guns	Increases the ship's Anti-Air capability.	Slightly reduces ship's Maximum Speed.
Torpedo Launcher	Increases the ship's Torpedo Attack.	Slightly reduces the ship's Maximum Speed.
Torpedo Tubes	Increases the ship's Torpedo Attack.	Not as powerful as Torpedo Launchers.
Armor	Increases the ship's Armor. Increases the ship's HP.	Reduces the ship's Maximum Speed. Armor on ships heavier than Cruisers increases Surface Visibility.
Fire Control System	Grants a percentage bonus to the ship's Light, Heavy, and Anti-Air Attack.	Advanced systems reduce overall Reliability.
Sonar	Increases Submarine Detection.	Takes up a slot that could go to other components.
Radar	Increases Surface Detection. Slightly Increases Submarine Detection. Advanced systems grant a percentage bonus to Light, Heavy, and Anti-Air Attack.	Takes up a slot that could go to other components.
Depth Charges	Allows use of Depth Charges.	Slightly reduces the ship's Maximum Speed.
Minelaying Gear	Allows Minelaying.	Advanced systems slightly reduce the ship's Maximum Speed.
Minesweeping Gear	Allows the ship to clear enemy mines.	Slightly reduces the ship's Maximum Speed.
Hangar Space	Allows the ship to house airplanes.	Reduces the ship's Maximum Speed. Requires an additional 500 Manpower.
Aircraft Facilities	Increases Surface and Submarine Detection.	Slightly reduces the ship's Maximum Speed.
Snorkel	Reduces Submarine Visibility.	Takes up a slot that could go to other components.