Military history / THE FIELD NOTES
Hearts of Iron IV
Industry, alliances, and the enormous consequences of a very small arrow on a map.
The basics
Find your footing. Three short notes to get you into the game.
Your country before your first order
You manage a nation through World War II: its politics, research, industry, and military. Those systems work together, so start with a modest goal rather than a continent-sized offensive.
Try it next sessionIdentify your political direction, available research, and existing army.
Research, factories, equipment
Research opens possibilities; production turns plans into equipment. Designing a force and supplying that force are different jobs. Learn what your factories are producing before expanding your ambitions.
Try it next sessionTrace one equipment type from research to its factory assignment.
Armies and division templates
A division template describes an army unit’s composition. Different compositions ask different things of your industry. Start by inspecting an existing design rather than copying a supposedly universal build.
Try it next sessionCompare two existing templates and the equipment they call for.
Connect the dots
Intermediate starting points: questions to explore once the main systems feel familiar.
Make the industrial plan match the military plan
Treat a new army design as a production decision too. Ask what equipment it needs, what you can make, and which other priorities would have to wait.
Try it next sessionWrite down one military goal and its production requirements.
Bring politics into the war plan
Diplomatic alliances and political objectives shape who fights alongside you and which direction your country takes. Read the political choices before committing to a military timetable.
Try it next sessionFind one political decision that supports your intended campaign.
Think across land, sea, and air
A global war gives you more than one theater to consider. Use your next session to examine how your army plans fit the other forces and resources available.
Try it next sessionPick one operation and list the forces you would need.
The deep end
PLANNED / NOT YET WRITTENThis is our desk. Joshua and I will fill it with tested strategies, campaign notes, and the mistakes worth learning from.
Division designs, tested by role
This guide is on our list. We’ll add the approach, an example from a real campaign, and where it falls apart.
Before it joins the notebookRecord the game version, expansions and mods, starting conditions, and what we actually tested. No strategy has been published here yet.
Supply and operational planning
This guide is on our list. We’ll add the approach, an example from a real campaign, and where it falls apart.
Before it joins the notebookRecord the game version, expansions and mods, starting conditions, and what we actually tested. No strategy has been published here yet.
Country openings and multiplayer coordination
This guide is on our list. We’ll add the approach, an example from a real campaign, and where it falls apart.
Before it joins the notebookRecord the game version, expansions and mods, starting conditions, and what we actually tested. No strategy has been published here yet.
The reading behind these notes
These starter notes draw on the official game descriptions below. The exercises and intermediate connections are suggested ways to learn, not tested optimization guides.
Official Paradox game overview ↗ · Publisher’s Steam description ↗Sources reviewed 16 September 2026. Broad concepts only; no patch-specific validation. Features and interfaces may vary with updates, expansions, mods, and platform.