Patch 1 19 — After Strategy

HOI4 Beginner's Guide 2026: Tips for Your First Campaign (Patch 1.19.4)

Thu, 12 Nov 2026 00:00:00 GMT

Ten years after launch, Hearts of Iron IV still punishes one mistake harder than all the others: building an army before you have an industry. Patch 1.19.4, released on October 27, 2026, strips away some of the busywork with automated resource trading. But the rule stands, and what matters is still the order: industry first, army second.

Nation: the United States to learn the economy, Hungary or Romania to learn the front.
First years: civilian factories first, economy laws next, military factories as war approaches.
Research: industry and construction first, never too far ahead of the calendar.
Army: simple templates, one general per 24 divisions, a front line before any offensive.

This guide draws on the official patch notes, the game’s wiki and specialist guides, all linked in the text.

HOI4 in 2026: which version, which DLC

The current version is 1.19.4, released on October 27, 2026 and hotfixed on October 29 and November 5. The official Steam patch notes include several helpers that matter to newcomers. Resource trading can now be automated: you set aside a number of factories and rank the resources to import. A Shift+click on a missing resource triggers an instant import. And the focus tree finally gets a mini-map.

The latest released DLC is Thunder at our Gates, a Theater Pack covering Australia, Siam and the Dutch East Indies. It has been available since June 11, 2026 for $19.99 (€19.99). The free update that shipped with it gave regimental support to every player, DLC or not. Next in line is a Romania focus pack, covered in Dev Diaries up to the November 3, 2026 entry. No release date or price has been announced.

For a first campaign, no DLC is required. The base game already has production, research, laws and battle plans. Our HOI4 DLC buying guide can help later, once you know which nations you enjoy. The real subject of a first campaign is production.

Which nation for your first campaign

Start the 1936 scenario (“The Gathering Storm”), not 1939. It gives you several years to build an economy before the shooting starts, while 1939 drops you a few weeks before the invasion of Poland. Gamer Empire’s beginner guide also suggests leaving Ironman off and historical AI focuses on. You can reload after a blunder, and the AI follows a path you can read.

On the nation itself, guides contradict each other. The United States comes up most: Gamer Empire recommends it for learning industry and the focus tree, and Gamers Decide ranks it first for beginners. Its strength comes down to one thing: time. If you play the US, you build factories while Europe rearms, with no threat on your borders.

Hungary and Romania teach something else. As minor allies of Germany, they fight the war without carrying it: a botched offensive will not bring down the Axis. Gamer Empire warns against Italy, stretched between the Mediterranean and the African front, and against the United Kingdom. The risk with Romania: its focus pack will bring a new tree, so playing it now means learning content that is about to change.

For a ranking by goal (learning, winning, challenge), see our HOI4 best nations tier list.

The first days: focuses, laws and political power

Three habits at game start are worth more than an hour of reading. Always keep a national focus running: a day without one is a day wasted. Spend political power on laws and advisors rather than diplomacy, as Gamepressure points out. And look for the focuses that grant factories or a research slot: they speed up everything else.

Economy laws go up in this order: Civilian Economy, Early Mobilization, Partial Mobilization, War Economy, Total Mobilization. Each step lowers the share of factories tied up in consumer goods, freeing them for construction. In practice, it is the first industrial lever of any campaign. According to the official wiki, each change costs political power and requires a certain level of war support. Keep an eye on stability too: when it drops too low, penalties and unwelcome events follow.

Production: civilian factories first

Every guide repeats it: build civilian factories before military ones. Civilian factories construct everything, military factories included, and they pay for your imports. A single project accepts at most 15 civilian factories, which is why you should run several projects side by side. Military factories take over once war approaches and your laws have freed up capacity.

Trade is expensive: each batch of 8 units of an imported resource ties up one civilian factory. A missing resource, such as aluminum for aircraft, slows every line that depends on it. The automated trading of 1.19.4 stops you from forgetting those imports, as long as you cap the number of factories it can use. The risk otherwise: your construction slows down and you cannot tell why.

On the military side, start with infantry equipment, then support equipment and artillery. A production line’s efficiency climbs slowly and drops partly when the line switches equipment, as the wiki’s Production page explains. One rifle line running since 1936 beats three lines reassigned every six months.

Research: industry before tanks

Research slots are the scarcest resource of the early game. Dedicate at least one to industry and construction, which speed up your factories and building projects. Do not reach too far ahead: a technology started before its historical year takes noticeably longer. Patch 1.19.4 also adds keyboard shortcuts in the research window, so you no longer need to open every detail panel.

Doctrines come next. Switching doctrines midway costs the experience already invested, so pick one and stick with it for your first campaign. On paper, rushing tanks, planes and ships is tempting. In practice, a medium tank technology is worthless without factories to equip it.

Divisions, generals and your first battle plan

Do not reinvent your divisions in 1936. The starting templates are enough to learn with, and every edit costs army experience. When you are ready, the best division templates guide covers combat width and regimental support for the current patch. What matters for a beginner: a fully equipped division beats a large one at half strength.

Next, group your divisions into armies. A general commands 24 divisions without penalty, and a field marshal coordinates several armies. In the general’s panel, draw a front line along the border first, then an offensive line into enemy territory. According to the official wiki, divisions waiting on their line build up a planning bonus that wears off during the offensive. So prepare your plans before declaring war.

The last trap is supply. An army out of supply can no longer attack, and a region with poor infrastructure cannot feed many divisions. Before advancing, the logistics map is the watch point: an offensive that stretches far from the railways grinds to a halt on its own. Naval landings follow their own rules, covered in our guide on how to pull off a naval invasion in HOI4.

Mistakes that sink a first campaign

Building the army before the industry. Divisions without rifles cannot hold a front, however many there are. The civilian factories of the early years decide your output in 1940.
Leaving trade uncapped. With automated trading, set a maximum number of factories. Gamepressure notes that sinking too many factories into trade cripples the early economy.
Researching ahead of history. The time penalty makes those technologies slower than two on-schedule projects.
Constantly reassigning production lines. Every switch costs efficiency.
Ignoring war support. Without it, economy laws stay locked, and so do your factories.
Attacking without a front line. An improvised offensive loses its planning bonus and leaves holes in the defense.

To test an idea without waiting three in-game years, the HOI4 console commands can fill stockpiles or complete a focus. Keep them for experiments, not for winning: a campaign won through the console teaches nothing.

What to watch

Two things could change this advice. The Romania focus pack has no date yet, and it will bring a new tree for one of the nations most often suggested to beginners. And on October 7, 2026, Paradox opened an energy open beta that would tie production to power plants, without deciding whether to release it. If that system ships, where your factories sit will matter as much as how many you have. Until then, a 1936 US campaign remains the clearest economics lesson HOI4 has to offer.

Going further

HOI4: how to do a naval invasion (patch 1.19.4)

Mon, 02 Nov 2026 00:00:00 GMT

A naval invasion in Hearts of Iron IV launches when five conditions are met: a departure port, enough convoys, enough invasion capacity, finished preparation and over 50% naval supremacy in every sea region crossed. For patch 1.19.4 of October 27, 2026, the procedure comes down to four steps:

Select an army and pick the naval invasion order.
Click a departure port, then right-click the target coastal province.
Wait for preparation to finish, with a fleet on naval invasion support.
Launch as soon as the arrow turns green, then go for an enemy port.

The mechanic is part of the base game. The Floating Harbor requires the No Step Back DLC, and the marine sub-doctrines depend on Arms Against Tyranny.

The five conditions to check before launching

The official wiki and the Guild Order guide list the same locks. The game does not present them in order: the invasion arrow only tells you something is missing.

A departure port. A province with a naval base, yours or one belonging to an ally not at war with the target.
Free convoys. Each division uses them according to its weight, rounded up. An armored division needs far more than light infantry.
Order capacity. It starts at 4 divisions per order and 1 simultaneous plan. Naval transport technologies raise both.
Preparation. It must reach 100% before launch.
Naval supremacy. Over 50% in every sea region along the route, not just off the beach.

If you assign more divisions than the capacity, the order shows zero transports and the divisions keep their red exclamation mark. This is the most common beginner mistake. What matters is reading the transport count before blaming the fleet.

Naval supremacy: the real lock

Supremacy is measured per sea region. It adds up the contribution of your fleets present there, weighted by their mission. The guides-factory navy guide uses the wiki’s coefficients:

Mission	Share of supremacy counted
Strike force or invasion support	100%
Patrol	75%
Convoy escort	50%
Convoy raiding, minelaying or minesweeping	25%
Naval exercises or hold	0%

A fleet set to do not engage counts for nothing. Air superiority adds up to +100%: in a zone where you own the sky, every ship counts twice.

Naval intel matters as much as the fleet. Below 40% naval intel efficiency against the enemy, your supremacy is reduced; at 10% or less, it is halved. In practice, a spy network, coastal radar and recent naval battles help you clear that threshold.

On paper, supremacy is only checked at launch: once the 100% preparation bar turns into a moving fleet, the invasion proceeds even if the enemy fleet comes back. The risk is elsewhere. Raiders hitting your convoys during the crossing heavily delay the landing, and a delayed landing gives the defender days to move reserves to the beach.

Preparation: why it takes months

With early technology, count about 7 days per division: 1 division needs 7 days of preparation, 10 divisions need 70 days. Naval transport technologies cut that delay. Preparation advances while divisions travel to the port, so assign the order before they even arrive.

Planning bonus, however, barely rises for an invasion: the game applies a heavy penalty to its build-up. In practice, waiting longer after 100% gains nothing. Launch as soon as preparation is complete.

What matters for timing is the calendar of the war, not the bar itself. A 10-division plan started in January 1940 only reaches 100% around mid-March with early technology, so plan the invasion before the target theatre becomes urgent. The risk of starting late is landing when the enemy already has divisions free to counterattack.

Several invasions can prepare in parallel from different ports, up to your simultaneous plan limit. This is the safest way to land a large army: three 4-division orders on three nearby beaches rather than one giant order.

Holding the beachhead: ports and the Floating Harbor

A successful landing is only half the job. Without a captured port or coastal city, your divisions are cut off from supply and draw on their reserves. The priority target after the beach is the nearest port. Pick the beach based on that port, not on how weak the defence looks.

The Floating Harbor, added with No Step Back, solves this problem for a while. The supply dev diary describes it as an artificial harbor inspired by the Battle of Normandy. It works in three steps.

Production. It unlocks through research, then is produced in naval dockyards like a ship.
Order. You need one in stock and must pick the naval invasion order with Floating Harbor support.
Effect. It is consumed at launch and immediately creates a stocked supply hub at the landing site.

That hub is temporary. Paradox speaks of a few weeks to a few months depending on enemy air superiority; a Gamer Empire guide puts it at 30 days. The Floating Harbor buys time, but it does not replace taking a real port.

Which divisions to send

Divisions landing against resistance suffer an attack penalty. Marines, engineers, amphibious vehicles and flame tanks handle it better, according to the wiki; heavy equipment handles it worse. If you play a low-industry nation, a good first wave combines marines and engineers, with armor in the second wave once the port has fallen.

On width, a naval invasion adds an attack direction to the battle. Our division templates guide recommends 20 to 25 width to leave room for reinforcements on the beachhead.

Since patch 1.19.0, special forces have moved to the new doctrine system. The Paradox dev diary states that marine sub-doctrines, including Marine Commandos, are tied to Arms Against Tyranny. Patch 1.19.4 also strengthens amphibious tanks: their HP now depends on reliability, going from 2 to 3.5 at 100% reliability or more.

Why your naval invasion will not launch

When the arrow stays red, hover over it: the tooltip shows the missing condition. The causes always come back in the same order.

Not enough supremacy along the route. A single region crossed below 50% is enough to block it. Switch fleets to strike force or invasion support rather than patrol.
Naval intel too low. Below 40%, your fleet counts for less than it seems.
Not enough convoys. Convoys also serve trade and overseas supply; build more before launching.
Too many divisions in the order. Remove some until you are back under capacity.
Preparation incomplete. It must reach 100%.

Patch 1.19.4 adds a handy shortcut to start over: Alt+Delete removes every airborne and naval invasion order from the selected divisions.

Defending against a naval invasion

Since patch 1.19.0, the AI is more willing to try advantageous naval invasions, according to the anniversary update diary. For an exposed coast, the area defense order lets garrison divisions guard ports and coastline. Keep a few mobile divisions in reserve near the main ports: the invader has to take one, so that is where to wait.

In practice, the defender also benefits from geography. A coast with few ports forces the attacker to commit to one target, so a single well-placed division with engineers can hold long enough for reinforcements. Coastal forts on the main ports make this even harder, since the attacker cannot rely on the Floating Harbor forever.

The best defence is still at sea. A fleet that contests supremacy, or submarines raiding convoys, delay or block the invasion before it even reaches the beach.

Going further

HOI4 best division templates in 2026 (patch 1.19.4)

Sat, 31 Oct 2026 00:00:00 GMT

A Hearts of Iron IV template is no longer something to copy from a 2024 spreadsheet. Since Thunder at our Gates, regimental support adds stats without taking width, and patches 1.19.3 and 1.19.4 have repriced those shortcuts. The short answer for patch 1.19.4 of October 27, 2026: 9 to 10 infantry battalions (18-20 width) to hold, 25 width to attack, 30 to 35 for armor, 25 in mountains.

Line holder: 9-10 infantry, engineers and support artillery, Heavy Weapons Companies as regimental support.
Attack infantry: 11 infantry and 1 line artillery (25 width).
Armor: medium tanks and motorized or mechanized infantry in roughly equal shares, 30 to 35 width.
Mountain: 25 width, so two divisions fill the front exactly.

These recommendations come from the official patch notes and up-to-date community guides, cited below. Treat them as starting points to adjust for your doctrines and industry.

Pick width from terrain first

Every battle has a fixed width set by the terrain of the defended province, increased with each extra attack direction. The official wiki gives these values:

Terrain	Base width	Per extra direction
Plains, hills, desert	70	+35
Forest, jungle	60	+30
Mountain, marsh	50	+25
Urban	80	+40

Going over that width costs 1% efficiency per percentage point of excess, up to -33%. An infantry or armor battalion takes 2 width and line artillery takes 3. Support companies, divisional or regimental, add none.

The math explains why 20 and 25 keep coming back. Three 20-width divisions fill a forest front exactly (60), four fill an urban front (80). Two 25-width divisions fill a mountain (50); three of them on plains overshoot by only 7%. Two 35-width divisions fit plains exactly (70), but only one fits a mountain without penalty.

Doctrines blur that math: since 1.19.4, Large Unit Tactics cuts infantry width by 0.2 instead of 0.3, and the Mass Assault milestone adds another 0.2 reduction. Trust the combat width indicator the designer now shows directly in the grid since update 1.19.

What regimental support changes

The Paradox dev diary presents regimental support as an extra row under each regiment. It works like divisional support: more stats, without overloading width. Two limits apply.

A regiment needs enough line battalions to unlock its slot. In the official screenshot, a one-battalion regiment stays locked.
Not every company is available for every line battalion type. The designer only offers the ones compatible with the regiment.

For infantry, the choice covers five companies: Infantry Guns, Anti-Air Battery, Anti-Tank Battery, Heavy Weapons Company and its motorized version. Each one costs army experience to add.

Patch 1.19.3 of September 17, 2026 repriced them. The Heavy Weapons Company goes from 20 to 30 organization and from 0.4 to 0.6 max strength. Infantry Guns and the Rocket Battery need 6 equipment instead of 4, with a penalty normalized to -75%. Anti-Air Batteries go from 12 to 16 equipment, and Anti-Tank Batteries from 120 to 180 manpower. For a line division, heavy weapons have become the most cost-effective option.

Line template: hold the front at 18-20

This is the template to mass-produce. Up-to-date guides from stratemgames and grandstrategy-hub agree on the same base:

9 or 10 infantry battalions (18 or 20 width);
support: engineers plus support artillery;
regimental support: 2 to 3 Heavy Weapons Companies.

Engineers bring entrenchment, and the Defensive Postures doctrine gives heavy weapons +0.2 entrenchment since 1.19.3. Against an AI fielding armor, swap one Heavy Weapons Company for an Anti-Tank Battery. Against a dominant air force, add an Anti-Air Battery.

For equipment-poor countries, a 5 infantry battalions plus engineers variant (10 width) works as a cheap filler on secondary fronts. With half the HP of a 20-width division, it breaks quickly under a serious offensive.

Attack template: break through at 25

Patch 1.19.3 gave line artillery back its breakthrough role. Artillery Equipment breakthrough goes from 6 to 10 at level I, from 7 to 13 at level II, and from 8 to 16 at level III. The Sommarfältprov summer beta had already tested a buff to line artillery and heavy weapons before this patch.

Starting point for attack infantry:

11 infantry battalions and 1 line artillery (25 width);
support: engineers, support artillery, field hospital;
regimental support: 3 Heavy Weapons Companies.

Support artillery stays in the template, even though 1.19.3 raised its penalty from -40% to -50%. If artillery equipment runs short, drop the line battalion first: the division falls back to 22 width and keeps its supports.

Armor template: 30 to 35 with motorized

Armor remains the breakthrough tool. The grandstrategy-hub guide puts the width around 30, between 30 and 36, with tanks and mechanized infantry in roughly equal shares. Supports: recon, engineers, flame tanks, logistics and hospital.

Patch 1.19.4 shifts the balance between those battalions.

Motorized infantry gains HP, from 25 to 27.5.
Mechanized infantry loses its 10% soft attack bonus. Improved Infantry Equipment partly offsets this, now giving +10% to both.
Tanks draw HP from reliability. At 100% reliability or more, a tank goes from 2 to 3.5 HP.

In practice, motorized is a good compromise again for a mid-industry country, and reliability becomes a tank designer criterion. Avoid tank destroyers as regimental support: since 1.19.3 they need 15 vehicles instead of 10, and 1.19.4 cut their HP from 0.2 to 0.1.

Mountain, marines and garrison

In mountains, the front is only 50 wide. Two 25-width divisions fill it without penalty, roughly 12 mountaineer battalions, each taking 2 width like infantry. Add engineers and a support artillery company; line artillery, at 3 width, quickly weighs these divisions down.

For marines, remember one rule: a naval invasion adds an attack direction, and so more width, according to the official wiki. A 20 to 25 width division leaves room for the reinforcements landing on the beachhead behind it.

For garrisons, the goal is the opposite: the lowest cost. The cited guides recommend the cheapest cavalry or infantry, with a military police company as support.

Mistakes to avoid

What matters is not the strongest template on paper but the one your industry can actually equip. A division at 60% equipment loses more than a smaller division at full strength.

Stacking regimental support without checking the factories. Three Heavy Weapons Companies per division, across 48 divisions, means 144 companies to equip. If your production lines cannot keep up, drop one.
Keeping a 40-width infantry template. In a forest, a single 40-width division already overflows the 60-width front as soon as a second one joins: the overwidth penalty kicks in fast.
Forgetting the field hospital on attack divisions. It reduces experience losses, and experience is exactly what pays for regimental support.
Changing an army’s template while it is on the front. Every change sends the removed equipment back to the stockpile, and new battalions arrive without equipment. Do it during a lull instead.

On paper, every guide offers its ideal grid. In practice, if you play a small nation, the 10-width template and a well-equipped 18-width line are worth more than a half-empty army of 25-width divisions.

What to watch

Three patches between June 11 and October 27, 2026 (1.19.0, 1.19.3 and 1.19.4) have touched regimental support, artillery and armor. The next one may still move the thresholds: check the release notes before reworking your whole army. To test a template without waiting for production, the HOI4 console commands let you fill stockpiles and compare two variants in a few minutes.

Going further

HOI4 Thunder at Our Gates: Guide to Australia, Siam and Dutch East Indies (Patch 1.19)

Sun, 21 Jun 2026 00:00:00 GMT

HOI4 Thunder at Our Gates: The Asia-Pacific Finally Takes Center Stage

Released on June 11, 2026 alongside the free Patch 1.19 “War Effort”, the Thunder at Our Gates Theater Pack gives complete national focus trees to three nations long confined to background roles in Hearts of Iron IV: Australia, Siam, and the Dutch East Indies.

For players who always wanted to challenge Japan from the Pacific, contest colonial dominance, or reshape Southeast Asian geopolitics, this is arguably the most anticipated HOI4 DLC in years.

This guide covers the key paths for each nation, the new mechanics introduced by the pack, and strategies to get the most out of every focus tree.

Australia: elections, alternate history and logistics
Siam: coup or reform, then empire
Dutch East Indies: oil, independence and the petition
Army HQs and Ship Captains
Patch 1.19 War Effort: what changes for everyone

Australia: Elections, Alternate History and Logistics Challenges

Australia is the flagship nation of this pack. Caught between the wounds of the Great Depression and growing demands from London, it offers one of the most nuanced political trajectories ever built into HOI4.

Historical / Loyal Commonwealth path: the most accessible branch for new players. You maintain ties with Britain, benefit from British logistical support, and your troops join the North African or Pacific fronts as Allied needs dictate. This path faithfully simulates Australia’s historical role and provides natural progression through 1942.

Nationalist / Australia First path: the major alternate history fork. The tree splits around a leadership question:

Under P.R. Stephensen, Australia demands total emancipation from the Commonwealth, can strike a deal with Nazi Germany, and follows an aggressively nationalist authoritarian course
Under Adela Pankhurst Walsh, the country gradually distances itself, capitalizing on British strength before declaring sovereign independence in the late 1930s

Communist path: inspired by powerful labor movements of the 1930s, this branch revolutionizes the Australian economy and aligns the country with the USSR. Politically difficult to manage (public opinion is conservative), but rewarding for players who enjoy high-risk runs.

The Canberra Air Disaster event is one of the most original narrative pivots ever built into HOI4. This real air crash that killed several cabinet ministers in 1940 is recreated as a major event redistributing political power mid-war. Depending on your focus branch, it can destabilize a fragile coalition or accelerate an authority transfer.

Key constraint to plan around: low population density and geographic dispersion (coast vs. interior) create realistic logistical challenges modeled by Paradox. Build your rail network from 1936 — Pacific supply lines will not forgive shortfalls.

Siam: Coup or Constitutional Reform, Then Empire

Siam (modern-day Thailand) is one of the few Southeast Asian nations to have preserved its independence from colonial powers — at the cost of constant compromise. Thunder at Our Gates finally makes it a full gameplay subject.

The core question: from turn one, the Siamese tree depicts the fracture within the Khana Ratsadon — the party that had peacefully overthrown absolute monarchy in 1932. By 1936, its civilian and military wings are pulling in opposite directions, and it falls to the player to decide.

Civilian constitutional path: fragile but legitimate. You prioritize progressive industrialization, social reforms, and an active neutrality diplomacy that can carry you through the war without occupation. Siam’s unique rapid industrialization mechanic is at its strongest here, enabling unprecedented economic growth for a nation historically marginal in HOI4.

Military coup path: stability at the cost of freedoms. The military axis favors rapid mobilization and authoritarian politics, useful if you anticipate early conflict with French colonizers or Japan. Suppressing freedoms takes a long-term toll on domestic stability.

The Rattanakosin path: the most spectacular option in the pack. Drawing on the historical memory of the Rattanakosin Kingdom, you seek to unify Thai peoples across neighboring territories — Burma, Laos, Malaya. This aggressive strategy requires precise timing (exploiting British or French colonial weakness) but offers the chance to build a significant Asian regional power with no precedent in HOI4.

Practical tip: regardless of your path, stockpile rubber and oil from 1936. Siam will be coveted — negotiate your neutrality from a position of economic strength.

Dutch East Indies: Oil, Rubber and Colonial Destiny

The Dutch East Indies (modern Indonesia) represented a glaring gap in HOI4: a nation of critical strategic importance to Imperial Japan, yet with no national focus tree worth the name. Thunder at Our Gates addresses this with a tree centered on vital resources and political identity.

The Soetardjo Petition is the central mechanic. This historical 1936 document requesting progressive autonomy from the Netherlands triggers an event approximately 140 days into the game. Your response determines the colony’s political path:

Loyalist path: you remain under Dutch authority and benefit from The Hague’s military support, but face the 1941-42 Japanese invasion without room for error
Autonomy path: a middle road negotiating progressive competency transfers while maintaining economic cooperation with the Netherlands
Independence path: highest risk, highest reward. Managing the break with the Netherlands, preparing for potential conflict on two fronts (colonial and Japanese), but able to build a sovereign Indonesian state before 1942

Resource management is decisive across all paths. The Dutch East Indies hold one of the largest oil and rubber reserves of 1936 — resources Japan must control to fuel its war machine. Negotiating their access or actively defending them directly influences Imperial Japan’s strategic decisions.

The indigenous military forces (KNIL — Royal Netherlands East Indies Army) and local volunteers have distinct focus branches, reflecting the complexity of colonial military cooperation.

Army HQs and Ship Captains: Two Mechanics That Change the War

Thunder at Our Gates adds two mechanics available to all nations that own the DLC.

Army Headquarters: generals can now be deployed to an advanced command post at the front, buffing adjacent land units through command synergies. A good general in the right position can flip a defensive battle — but an over-extended HQ is vulnerable to enemy breakthroughs. Capturing an enemy Army HQ general triggers massive morale penalties on surrounding units.

Ship Captains: a direct extension of the naval system introduced in Götterdämmerung, this mechanic lets you assign named officers to your capital ships. Each captain develops skills through combat and can be promoted to admiral commanding entire squadrons. Players investing in naval power — Australia and Dutch East Indies especially — will see significant returns on naval efficiency.

Patch 1.19 War Effort: Improvements for Everyone

Even without buying Thunder at Our Gates, Patch 1.19 “War Effort” released June 11 improves the HOI4 base experience:

Deep naval overhaul: new fleet AI model, rebalanced submarine detection, restructured naval templates
Click reduction technologies: significantly fewer repetitive clicks for mass actions (general assignments, supply chain logistics)
Indonesia revision: even without the DLC, the base Indonesian content receives improvements
Performance optimizations: better handling of late-game performance (1943 and beyond)

A hotfix 1.19.0.1 was deployed shortly after release to address the most critical launch bugs.

Conclusion: Thunder at Our Gates Finally Opens the Pacific

Thunder at Our Gates delivers exactly what HOI4 Pacific theater players have been waiting for: three nations with genuine political and historical depth, two mechanics that enrich combat for everyone, and a solid free patch for the entire community.

For background before diving in, our Thunder at Our Gates preview covers Paradox’s original announcements. You’ll also find context in our War Effort patch breakdown.

Patch 1 19 — After Strategy

HOI4 Beginner's Guide 2026: Tips for Your First Campaign (Patch 1.19.4)

HOI4 in 2026: which version, which DLC

Which nation for your first campaign

The first days: focuses, laws and political power

Production: civilian factories first

Research: industry before tanks

Divisions, generals and your first battle plan

Mistakes that sink a first campaign

What to watch

Going further

HOI4: how to do a naval invasion (patch 1.19.4)

The five conditions to check before launching

Naval supremacy: the real lock

Preparation: why it takes months

Holding the beachhead: ports and the Floating Harbor

Which divisions to send

Why your naval invasion will not launch

Defending against a naval invasion

Going further

HOI4 best division templates in 2026 (patch 1.19.4)

Pick width from terrain first

What regimental support changes

Line template: hold the front at 18-20

Attack template: break through at 25

Armor template: 30 to 35 with motorized

Mountain, marines and garrison

Mistakes to avoid

What to watch

Going further

HOI4 Thunder at Our Gates: Guide to Australia, Siam and Dutch East Indies (Patch 1.19)

HOI4 Thunder at Our Gates: The Asia-Pacific Finally Takes Center Stage

Table of Contents

Australia: Elections, Alternate History and Logistics Challenges

Siam: Coup or Constitutional Reform, Then Empire

Dutch East Indies: Oil, Rubber and Colonial Destiny

Army HQs and Ship Captains: Two Mechanics That Change the War

Patch 1.19 War Effort: Improvements for Everyone

Conclusion: Thunder at Our Gates Finally Opens the Pacific

Sources