Hearts of Iron IV Dev Diary | Industrial Might & Military Production

Greetings, Commanders! Welcome to another edition of the Hearts of Iron Dev Corner, where we dive deeper into military production.

I am Zwirbaum, a Game Designer for Hearts of Iron. This update serves as a direct follow-up to our previous Military Production Dev Corner, following the incredible amount of constructive feedback you shared with us. We noticed several community concerns regarding upcoming system changes, and we want to provide additional clarity on the direction of our current development. Please keep in mind that everything shown today is a work in progress—expect plenty of whimsical placeholder art (including some of my own handiwork). Content, mechanics, and balance are still actively evolving and will look different by the time they are released.

Breaking away from our usual routine, I am lifting the veil a bit to share a glimpse of our current progress and what lies ahead. While this update might be a bit more straightforward than usual, I appreciate you bearing with me.

One of our primary goals was to introduce greater depth to the game’s industrial mechanics. We wanted the physical placement of your factories to carry more weight and to create meaningful distinctions between military facilities, rather than treating them as a single, homogenous national pool. The real challenge was figuring out how far to push this ambitious vision without completely uprooting the existing framework. After carefully weighing our options, I proposed what my teammates have learned to call a “Crazy Idea”…

ENTER THE INDUSTRIAL PARKS

(We are using France strictly for illustrative purposes—no hidden meanings or subtle hints intended!)

Industrial Parks represent a brand-new building classification featuring two distinct variants: Military Industrial Parks and Shipyard Industrial Parks (names are, of course, subject to change). These facilities act as specialized complexes dedicated to manufacturing specific categories of equipment under a single unified umbrella. Let us take a closer look at how they function.

Industrial Parks feature fully finalized icons adorned with pink stars. We will not discuss [REDACTED]. There is no [REDACTED].

In short, Industrial Parks create synergies with the local state where they are constructed. These bonuses can influence growth rates, improve factory efficiency, or utilize locally sourced resources to reduce the material costs of active production lines.

An example of the localized synergies gained by constructing a Military Industrial Park in the state of Rhône.

In the updated user interface flow, constructing an Industrial Park prompts you to assign a specific Corporation. In the screenshot above, for example, I am selecting Morane-Saulnier to establish a Light Aircraft Industrial Park, which in turn grants valuable reductions in aluminum maintenance costs.

Once established, your Industrial Park will focus on manufacturing equipment that aligns directly with the profile determined by your chosen Corporation. Sticking with our Morane-Saulnier example, this facility is capable of producing light aircraft, including standard fighters, carrier fighters, close air support (CAS), and carrier-based CAS.

Clicking the vibrant pink Industrial Park icon opens the production menu, displaying all valid, non-obsolete equipment variants tailored to that specific facility.

Production lines originating from an Industrial Park occupy their own dedicated subsection, allowing you to allocate specialized factories exclusively to that park to maximize its unique benefits.

Placeholder art showcasing upgrade paths designed by yours truly.

Furthermore, Industrial Parks gain access to specialized upgrades as they reach specific size milestones. Because these upgrade paths are currently in an early, placeholder state, please disregard any placeholder values or rudimentary modifiers you might notice. We will share a comprehensive breakdown of how upgrades will impact industrial complexes once those systems are closer to completion.

WHAT LIES AHEAD?

Before concluding this Dev Corner, I want to touch upon a concept we are currently exploring: expanding factory synergies into “Inter-Industrial Branch” relationships. For instance, could advancements in the artillery sector positively influence naval production or capabilities?

True to Dev Corner tradition, we want to hear your thoughts. Would you like to see us expand upon these interconnected industrial branches, or should each sector remain entirely self-contained within its original purpose?

We are eager to read your feedback and join the discussion.

Thank you for reading, and until next time—farewell!
/Zwirbaum

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