What changed in Hearts of Iron IV in 2017

New system for air warfare that accommodates Volunteer air wings.

A free patch released alongside the Waking the Tiger expansion.

New historical possibilities for Germany, including replacing Hitler or leading a democratic Germany.

Accompanying patch with various bug fixes and improvements.

Historical decisions and national missions for spending Political Power.

New system allowing for Volunteer air wings.

New expansion focusing on the Chinese front of World War II with new features and mechanics.

New expansion focusing on the Chinese front with new National Focuses and gameplay mechanics.

New paths for Japan including restoring Civilian Government or allying with the Soviets.

Players can unite armies under a field marshal to utilize generals' skills.

Generals can unlock powerful Command Power abilities.

Troops learn to survive in different environments, gaining advantages.

New National Focuses for Nationalist and Communist China to explore alternate histories.

New possible histories for Germany, including replacing Hitler or leading a democratic Germany.

Unite armies under a field marshal to utilize the skills of various generals.

Historical decisions and national missions added for Political Power management.

New National Focuses for Nationalist and Communist China to explore alternate histories.

New gameplay element allowing players to capture equipment during battles.

Troops learn to survive in extreme environments, gaining advantages in battle.

Generals can unlock powerful Command Power abilities for greater battlefield flexibility.

New paths for Japan including restoring Civilian Government or allying with the Soviets.

New mechanic for capturing battlefield equipment.

Experience the war from the difficult perspectives of these nations.

Players can now convert older units and utilize captured enemy vehicles and gear.

Three new thematic musical tracks and new voiceovers for troops.

License military technology and manage new subject levels for fascist countries.

The DLC introduces new content and features for the game.

The new DLC allows players to experience the war from the perspectives of Hungary, Romania, Czechoslovakia, and Yugoslavia.

Three new thematic musical tracks and new troop voiceovers have been added.

Update your arsenal by converting older units or using captured enemy vehicles.

New interactions for licensing military technology and establishing puppet states for fascist countries.

New focus trees for Hungary, Romania, Czechoslovakia, and Yugoslavia added to the game.

A variety of new non-historic portraits were added to the game.

The MXY7 Ohka now has custom art and works with the new air interface.

Players can now choose from more custom division symbols.

Community members contributed to new Polish troop voice overs.

A variety of new non-historic portraits were added to the game.

A free DLC focused on Poland was released to celebrate the one year anniversary of HOI4.

The MXY7 Ohka now has custom art and works with the new air interface.

Community members contributed to new Polish troop voice overs.

A free DLC focused on Poland was released to celebrate the one year anniversary of HOI4.

Players can now choose from more custom division symbols.

Fixes issues with match score calculations in AI template design.

AI now uses roles for template designs, improving scriptability and production priorities.

Fixes issues with match score calculations in AI template design.

Introduces a national spirit that boosts factory output.

Adds voice overs for troops and new 3D models for Czech tanks.

Adds voice overs for troops and new 3D models including tanks.

AI now groups target templates into roles for better design and production efficiency.

Introduces a national spirit that boosts factory output.

Significant adjustments to air zones to improve gameplay and historical accuracy, including splits and new zones.

Multiple new air zones added and existing ones split for improved gameplay, including Northern Scandinavia, Middle East, and others.

Significant adjustments made to strategic areas for better air coverage and naval landing support.

Players can now name air wings with nation-specific names instead of auto-generated names.

Introduced new National Spirits for Yugoslavia that affect national unity, political appointments, factory output, and officer recruitment.

Added ability to name air wings with nation-specific names instead of auto-generated ones.

New National Spirits for Yugoslavia that affect national unity, political appointments, factory output, and officer recruitment.

Various aspects of air combat mechanics have been rebalanced, including air detection and disruption stats.

Air Detection is now a visible stat in the air combat window, highlighting its importance in air missions.

Air wings now behave like divisions, allowing easier movement and mission assignment directly on the map.

Players can now assign missions to air wings directly from the mission panel, improving management efficiency.

The air wing interface has been redesigned to display air wings like army divisions, allowing easier management and relocation.

The air region window has been transformed into a new air combat window that provides detailed information on air combats.

The new combat window includes an overview of air superiority and bombing missions, with filtering options.

New visible radar overlays have been introduced, enhancing the visual representation of air control.

New visible radar overlays have been added for better situational awareness during air operations.

The air wing interface has been redesigned, removing the air base window and allowing for easier selection and management.

The air wing interface has been redesigned, removing the air base window and allowing for easier management of air wings.

Special combat icons have been added to the air map mode to indicate air support and combat status.

More visible radar overlays have been added for better situational awareness during air operations.

New stats for air detection and disruption have been introduced to enhance gameplay balance.

Players can now assign missions to air wings directly from the mission panel, improving management of air units.

The air wing interface has been redesigned to list air wings like army divisions, allowing for easier management.

Air wings now behave more like divisions, allowing for easier movement and mission assignment.

Players can now assign missions to air wings directly from the mission panel, simplifying the process of managing multiple air units.

The air region window has been transformed into a new air combat window, providing detailed combat information.

The air region window has been replaced with a new air combat window that provides detailed information on air combats.

Players can now assign missions to air wings directly from the mission panel, simplifying the process.

Visible radar overlays have been added to improve situational awareness during air missions.

A new Air Detection stat has been added to the air combat overview, improving strategic planning.

The air region window has been transformed into a new air combat window, providing detailed combat information.

New resource of Aluminum introduced in Asia.

Players can choose to restore the Hungarian People's Republic or invite Otto von Habsburg to the throne.

New resource of Aluminum introduced in the Asian region.

Introduction of new 2D and 3D art assets for Hungary.

Addition of new generals and leaders for Hungary.

An extensive event chain with 25 events and 16 different outcomes for peaceful annexation of territories.

Players can pursue the Bled Agreement to rearm freely, contingent on approval from surrounding nations.

Players can choose between an infantry heavy Home Defense branch or an offensive-focused Mobile Focus for military rebuilding.

An extensive event chain with 25 events and 16 different outcomes related to the annexation of territories.

Addition of new generals and leaders, including a notable admiral.

Hungary is represented as a Disarmed Nation with specific gameplay mechanics related to military restrictions.

Hungary is represented as a Disarmed Nation with no available manpower and a 50% construction speed penalty for military factories.

Players can choose between different military branches and methods to rearm Hungary after the Treaty of Trianon.

Players can choose to restore the Hungarian People’s Republic or invite Otto von Habsburg to take the throne.

Introduction of new 2D and 3D art assets related to Hungary.

Introduction of new gameplay features related to equipment conversion and licensing in the Death or Dishonor pack.

General optimizations to AI performance, making it easier to work with for future expansions.

New Country Pack focusing on Hungary, Romania, Czechoslovakia, and Yugoslavia with new National Focus trees.

New Country Pack focusing on Hungary, Romania, Czechoslovakia, and Yugoslavia.

Convert older units or use captured enemy vehicles and gear.

New Country Pack focusing on Romania, Hungary, Czechoslovakia, and Yugoslavia with unique national focus trees.

Enhanced the battle plan AI for better unit movement and responsiveness to front line changes.

Significant improvements to how AI manages expeditionary forces, particularly for Germany's operations in Africa.

Reworked battle plan AI for better unit movement and responsiveness to changing front situations.

New military technology licensing and subject levels for fascist countries.

Addressed issues with German AI performance, including unit effectiveness and expeditionary force management.

License military technology and new subject levels for fascist countries.

Convert older units or utilize captured enemy vehicles and gear.

New mechanics and quality of life updates for airpower management.

Enhanced AI performance for Germany, addressing issues with front line effectiveness and expeditionary force management.

3 new thematic musical tracks, new art content for focus nations, and new troop voiceovers.

New mechanics and quality of life updates for airpower.

Implemented impassable terrain in the Sahara to reduce unnecessary conflict in Africa.

3 new thematic musical tracks and new troop voiceovers.

Significant improvements to how AI manages expeditionary forces, particularly for Germany.

New country pack focusing on Romania, Hungary, Czechoslovakia, and Yugoslavia with unique national focus trees.

Clarified world map with new impassable areas for tactical gameplay.

Clarified world map with new impassable areas for tactical gameplay.

Nations can now request licenses to produce foreign equipment in local factories, enhancing gameplay strategy.

Introduced new impassable areas to prevent AI over-committing troops in unrealistic regions like the Sahara.

Updated map textures for better clarity between different terrains, especially hills, mountains, and forests.

Set up impassable borders in areas like the Himalayas to create more strategic choke points.

New impassable areas have been added to the map to prevent AI over-committing troops in unrealistic regions like the Sahara.

Nations can now request licenses to produce foreign equipment in local factories, depending on relations.

Updated map textures for better clarity in different terrains, particularly hills, mountains, and forests.

King Carol II has a unique ability to recruit ministers at a lower cost, affecting gameplay strategy.

New voice overs for Romanian soldiers added to increase immersion during gameplay.

King Carol II has a unique ability to recruit ministers at a lower cost.

Introduction of 3D models for notable Romanian military equipment to enhance visual experience.

Romania receives new art assets to enhance immersion.

New voice overs added for Romanian soldiers to increase immersion.

Romania receives new art assets including general and leader portraits to enhance immersion.

New 3D models introduced for iconic Romanian military vehicles.

Romania's focus tree allows players to navigate alliances and develop military strategies during WWII.

Romania's focus tree allows for flexible alliances and military development options.

AI will no longer declare wars on countries that control no territory.

Added stockpiling amount to production screen. Changed text to icons.

Made save game name text field longer.

Fixed a tooltip for the Australian focus 'A Deal with Japan' to account for different options.

Battleplans are now hidden during the peace conference to not obstruct the view.

Fixed legibility issues in event news.

Made AI better at dynamically evaluating level of preparation to attack based on expected enemy strength.

Building constructions and conversions can now be added at the top of the queue by holding ctrl and click.

When selecting a division(s), the list of all divisions automatically scrolls to show it.

Fixed wrong division flags in the combat screen.

AI is now inclined to ignore non-dangerous fronts while at war.

Italy AI should now be better at picking proper units to fight in Ethiopia.

AI will no longer declare wars on countries that control no territory.

Added alert about having unassigned divisions.

Made save game name text field longer.

Added alert about having unassigned divisions.

Added loading progress bars.

Italy AI should now be better at picking proper units to fight in Ethiopia.

AI will now start considering buildup of military constructions after a while, even if peaceful.

The AI should now be a lot better at handling a surrounded enemy capital.

Naval AI will now attempt to use strike fleets to aid in coastal land combats.

All message popups that don't require player choice automatically hide after timeout.

Added loading progress bars.

Fixed overlap of text in options with certain languages.

Naval AI will now attempt to use strike fleets to aid in coastal land combats.

Battle plan AI unit distribution should now be more stable.

It is possible to hide ALL map counters except your units. Hotkey 'M'.

AI should no longer be able to give units ridiculously long retreat or move orders while they are in combat.

Battleplans are now hidden during the peace conference to not obstruct the view.

Fixed rounding issue in resource mapmode.

Added tooltip to US 'Destroyers for Bases' focus to clarify territory gains.

Fixed the bug when capital icons were not correctly shown.

Battle plan AI unit distribution should now be more stable.

AI is now inclined to ignore non-dangerous fronts while at war.

AI is less spammy with call to arms and join war requests.

Fixed a tooltip for the Australian focus 'A Deal with Japan' to account for different options of territories transferred.

Fixed warscore not being calculated properly while war without majors on one side.

Resources have been made significantly more important in gameplay.

Final investigations into hardware compatibility before patch release.

Various optimizations and enhancements for user experience.

Introduction of new modding features and events.

Adjustments made to industry and infrastructure mechanics.

Introduction of new features for modding the game.

New mechanics for loot gained upon capitulation.

Changes to industry, infrastructure, and world tension mechanics.

Enhancements made to AI behavior and decision-making.

Efforts to make the gameplay map clearer and easier to read.

Announcement of upcoming 1.4 'Oak' update and a secret DLC with an axis focus.

Various quality of life improvements implemented.

Introduction of a new system for loot upon capitulation.

Enhancements made to AI behavior and performance.

Resources are now much more important in gameplay.

Celebration of breaking 500k sales of Hearts of Iron IV.

Plans to revamp the air system based on community feedback.

Significant improvements to the supply system, reducing its computing time from 65% to under 6%.

Significant improvements to the supply system, reducing its computing time from 65% to under 6%.

Optimized AI handling of division templates to reduce computational load.

Reduced performance issues caused by excessive naval pathfinding requests.

Introduced a loading progress bar for better user feedback.

Improved deployment AI for better management of lines and desired number of divisions.

CTRL+Click now sets building construction to top priority.

Reworked peace conference code to reduce slowdowns during large wars.

Optimized AI handling of division templates to reduce processing load.

Overall game speed improved by 14-18%, particularly reducing performance spikes.

Selecting a division now automatically scrolls the list to show it.

Added alerts for unassigned divisions, allowing players to toggle through them easily.

AI improved at calculating supply use when deciding how many divisions to field.

Reworked UI processing to significantly reduce the number of passes per frame.

Unassigned divisions now trigger alerts for better visibility.

Naval AI will now use strike fleets to aid in coastal land combats.

Added AI strategy for managing equipment stockpiles.

Fixed issue where AI would not counter resistance with area defense orders.

Added a toggle button to turn off the fog of war effect for better terrain visibility.

Reworked peace conference code to reduce slowdowns during large wars.

Production lines now face penalties calculated by each missing resource over multiple lines, potentially reaching -100% penalty.

Production lines can now receive penalties up to -100% due to lack of resources, calculated over multiple lines.

Lagging player notifications are now alerts that automatically disappear when the player catches up.

New AI strategy for managing equipment stockpiles based on division count.

Added a toggle button to turn off the fog of war effect for better terrain visibility.

Fixed an issue where AI would not counter resistance with area defense orders.

Improved naval AI region evaluation and its response to changing situations.

AI is now better at calculating supply use when determining the number of divisions it can field.

Improved deployment AI for better management of lines and division numbers.

Naval AI now evaluates regions better and reacts more efficiently to changing situations.

AI now has improved logic for lend leasing, including sending older equipment.

Introduced a loading progress bar.

A button to hide all counters except your units has been added, with hotkey 'M'.

Selecting a division now scrolls the list to show the selected division.

A new button hides all counters except your units, accessible via hotkey 'M'.

Improved AI logic for lend leasing, including sending old equipment and canceling leases.

CTRL+Click now sets building construction to top priority.

Lagging player messages now appear as alerts with tooltips explaining the situation.

Reworked UI processing to significantly reduce performance overhead.

Naval AI will now use strike fleets to aid in coastal land combats if not on a mission.

Overall speed improved by 14-18%, with significant reductions in performance spikes.

Infrastructure now affects the cost of building factories, making it more costly in less developed states.

Access to a percentage of a nation's equipment is granted upon capitulation, rather than only upon surrender.

Players now gain access to a percentage of a nation's equipment upon capitulation, rather than only after surrender.

War justifications now account for the size of the country being justified against, increasing world tension.

Production efficiency growth is now faster initially but slows down as lines become more efficient.

Production efficiency growth is now faster initially but slows down as lines become more efficient.

Infrastructure will now affect the cost of building factories in a state, making it more costly in less developed states.

Justifying a war now accounts for the size of the country, increasing world tension for major nations.

Trigger added to check for specific technology or category.

Added on_startup to onactions for modding.

AI will now consider changing non-hardcoded ideas based on ai_will_do value.

Modders can now change names of cities and victory points.

Added count_triggers, similar to calc_true_if in other projects.

New feature to separate industrial bonuses between factories and dockyards.

Trigger added to technology folders to hide tab and disable research for techs if trigger is not met.

Introduced a new industrial_capacity_dockyard modifier for dockyards.

Added local_non_core_manpower state modifier for modding.

Added trigger to technology folders to hide tabs and disable research if conditions are not met.

Modders can now change names of cities.

Fixed on_civil_war_end having a fixed random seed.

Added can_join_factions rule for modding.

Added dynamic technology folders that hide and lock technologies based on triggers.

Added new AI strategy 'template_xp_reserve' to modify AI's XP usage for division design.

Added an on action for on_annex, triggered from effects and peace conferences.

New ability to control the maximum number of factories assignable to production lines.

Added has_resources_amount trigger for modding.

Added dynamic technology folders that hide and lock technologies based on triggers.

Added set_state_category for modding.

Ability to control the maximum number of factories assignable to production lines.

Separated industrial bonuses between factories and dockyards for better balance.

Added proper error handling when reading scripted AI strategies.

Added proper error handling when reading scripted AI strategies.

Count triggers added, similar to calc_true_if on other projects.

Added has_tech_bonus trigger for specific technology or category.

Added an on action for on_annex, fired from both effect and peace conference.

Fixed the issue with on_civil_war_end having a fixed random seed.

Added set_state_name for modding.

Added new ai strategy 'template_xp_reserve' for modifying AI's XP usage for division design.

New music pack featuring 10 tracks illustrating moments of World War II.

New music pack featuring 10 tracks illustrating moments of World War II.

Work is being done on optimizations to speed up late game performance.

Introduced timed script flags that expire after a set duration.

Added console commands: set_ruling_party and add_party_popularity with ideology group shortcuts.

Ongoing optimizations to improve performance during late game.

Added triggers: has_full_control_of_state, has_army_experience, has_air_experience, has_navy_experience.

Added triggers: has_full_control_of_state, has_army_experience, has_air_experience, has_navy_experience.

Added timed script flags functionality for better event management.

Added modify_global_flag, modify_country_flag, and modify_state_flag effects with improved flag handling.

Added modify_global_flag, modify_country_flag, and modify_state_flag effects. Clearing script flags now removes them completely.

Introduced dynamic state, country, and global flags effects with commands like set_global_flag.

Added console command: set_ruling_party <ideology group> and add_party_popularity <ideology group> <value>.

Overview of resources and forums for getting started with modding Hearts of Iron IV.

Introduced dynamic state, country, and global flags effects.

Overview of resources and forums for getting started with modding Hearts of Iron IV.

The upcoming 1.4 Patch named 'Oak' will focus on late game performance improvements.

The upcoming 1.4 Patch, named 'Oak', will focus on late game performance improvements.

The upcoming 1.3.3 patch will include general improvements to balance.

The 1.3.3 patch will feature improvements to AI.

The Oak patch will focus on improvements to interfaces.

The Oak patch will focus on enhancing user interfaces.

The upcoming patch will include enhancements for modders.

The 1.3.3 patch will feature fixes and improvements to AI.

A significant amount of content for modders will be included in the 1.3.3 patch.

The Oak patch will include improvements to air warfare.

The 1.3.2 hotfix went live, focusing on bug fixes and improvements.

The Oak patch will include significant improvements to air warfare mechanics.

The 1.3.2 Hotfix went live, addressing various bugs.

The 1.3.3 patch will include balance improvements and bug fixes.

Resolved issue where ship transfer effects would sometimes transfer wrong ships or entire fleets.

Corrected two typos in the Indian focus tree/ideas.

Resolved crash to desktop issue when rapidly double clicking the first factory in a line.

Resolved huge slow down and eternal freeze issues during peace conferences.

Resolved issue where has_government trigger was functioning incorrectly.

Added script flags for the achievement if SAF chooses to puppet nations.

Fixed issue with Australia demanding New Zealand causing faction removal.

AST will join JAP if JAP is already the leader of a faction.

Trigger now requires same ideology to befriend Japan.

Mil to Civ factory conversion now properly removes the military factory.

Resolved crash to desktop issue when rapidly resetting factories.

Deployment is now allowed in locations where it is supposed to, regardless of capital state ownership.

Resolved issue where trigger did the opposite of intended.

Resolved crash to desktop issue when clearing country resources at the start of a civil war.

Transfer ship effect no longer incorrectly transfers wrong ships or fleets.

Resolved issue where dynamic tag side had no manpower in civil wars.

Tech tree now refreshes correctly after switching to a new puppet, resolving achievement issues.

Resolved issues with flags being set from events for immediate freedom in Crusader Kings 2 achievement.

Fixed issue where air accidents would happen during peacetime.

Wargoal on Australia will only be created if ideologies differ.

Factory conversion now properly removes the military factory.

Flags are now set correctly from events granting immediate freedom.

Tech tree now refreshes after switching tags, aiding achievement completion.

Script flags added if SAF chooses to puppet nations.

Resolved significant slow down and eternal freeze issues during peace conferences.

Trigger for Befriend Japan now requires same ideology.

Resolved issue causing units to disappear after peaceful annexation events.

Resolved potential crash to desktop issue during civil war starts.

Japan will only create a faction if it is not already in one.

JAP will only create a faction if not already in one.

AI now much better at respecting airbase size limits.

Australia will join Japan if Japan is already the leader of a faction and cannot befriend Japan if Japan is in another faction.

CTD safety added for voice over playing with broken sound drivers.

Japan now creates its own faction and adds New Zealand for the Befriend Japan focus.

Wargoal on AST only created if ideologies differ.

Deployment is now allowed in locations where it is supposed to, regardless of capital state ownership.

Resolved issue where Australia demanding New Zealand would kick Australia out of its faction.

Air combat delay reduced to allow combat in extreme time zones.

Added safety measures to prevent crashes related to voice over playback with broken sound drivers.

Resolved issue where dynamic tag side in civil wars would end up with no manpower and disband divisions.

Japan now creates its own faction and adds New Zealand for the Befriend Japan focus.

Resolved issue causing units to disappear after peaceful annexation.

Resolved issue where wrong ships or whole fleets were sometimes transferred.

Reduced air combat delay to allow combat in extreme time zones.

Resolved huge slow down and eternal freeze issues during peace conferences.

Resolved potential crash to desktop when clearing country resources at the start of a civil war.

AI now much better at respecting airbase size limits.

Resolved huge slow down and eternal freeze issues during peace conferences.

Tech tree now refreshes after switching tags, aiding in achievement completion.

Corrected two typos in the Indian focus tree/ideas.

Resolved crash to desktop issue when rapidly resetting factories.

Resolved issue where transfer ship effect sometimes transferred wrong ships or entire fleets.

Lowered air combat delay to ensure combat occurs in extreme time zones.

Implemented safety measures to prevent CTD when voice overs play with broken sound drivers.

Resolved issue causing units to disappear after peaceful annexation.

Tech tree now refreshes after switching tags, aiding achievement completion.

Deployment is now allowed in locations where it supposed to, regardless if your capital state is not owned by you.

Added safety measures to prevent CTD when playing voice overs with broken sound drivers.

Corrected two typos in the Indian focus tree/ideas.

Resolved crash to desktop issue when rapidly double clicking the first factory in a line.

AI now much better at respecting airbase size limits.

Fixed issue with Australia demanding New Zealand causing it to be kicked out of its faction.

Deployment is now allowed in locations where it is supposed to, regardless if your capital state is not owned by you.

Fixed issue with Australia demanding New Zealand causing faction removal.

Resolved issue causing units to disappear after peaceful annexation.