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Hello everyone!

Historia Universalis 0.83 — Rise of Orient I is now released!

This is the first update of the Rise of Orient project, focusing on major changes to medieval warfare, technology progression, AI economy, and the Orient.

Military & Combat Balance

Defensive Structures Reworked

Defensive structures have been significantly strengthened so that they can actually serve their intended defensive purpose.

Palisade → Walls → Castle

Their defense bonuses have been increased accordingly.

Terrain Defense Bonuses Increased

The defensive advantage of several terrain types has also been increased:

• Plains, Drylands, Steppes: +1 → +2
• Desert: +3 → +4
• Forest, Marsh, Savanna, Taiga, Semidesert: +2 → +3
• Hills, Tundra: +3 → +5
• Jungle: +4 → +5
• Mountains: +5 → +7

The overall goal is to reduce the problem of defenders being too weak, especially when defending favorable terrain.

Battle Width Adjustments

• Minimum Battle Width: 14 → 10
• Maximum Battle Width: 40 → 30

This is a deliberate gameplay decision. It moves slightly away from strict historical realism, but the intention is to give weaker nations a better chance to hold defensive positions for longer when fighting on favorable terrain.

Starting Army Sizes Increased

Starting armies have been significantly increased according to civilization rank.

This was mainly done to prevent situations in the 1066 scenario where Song could defeat and eliminate Liao far too quickly at the beginning of the game.

Unit & Technology System

Archers and Horse Archers are now separate unit types

Archers and Horse Archers are now handled separately by the game system.

Archers and siege units are also placed in the third combat row.

Technology Costs Increased

Technology costs up to the later medieval period have been increased by approximately 50%.

During testing, I observed that the AI was able to research most medieval technologies before 1300, including Full Plate Cavalry, which was far too early for the intended progression.

This change is intended to slow down medieval technological progression and prevent advanced medieval units from appearing too early.

Post-medieval technology costs will be adjusted separately in a future update.

Economy & AI

AI Economic Investment Rebalanced

After running a 300-year observer test starting in 1066, I found that some AI nations were investing far too heavily in economic buildings.

In particular, Song constructed more than 10,000 economic buildings during testing. XD;;;

The AI's tendency to prioritize economic investment has therefore been returned to the default vanilla value.

Temple Income Increased

• Income: 0.15 → 0.25

This is intended to provide a small additional source of income during the early game, when reliable sources of income are more limited.

Historia Universalis Content

• Added a dedicated Historia Universalis map (*Map credit: Poul Son of Wayne + Author's customize blending)

Notice : It is recommended that you do not use this mod together with other map mods.

• The 1066 scenario is now displayed by default on the main menu

https://preview.redd.it/zg2dbqvstakh1.jpg?width=1920&format=pjpg&auto=webp&s=7da5203b5390622f445615692bf374873a6f15df

• Added and rebalanced unique units for Goryeo and Liao
• Buffed Goryeo's unique units and fixed related issues
• Reduced the tendency for Goryeo to collapse too quickly during observer testing
• Major population rework across many regions of the Orient

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• Added new units and rebalanced various unit stats

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• Reorganized parts of the domestic development and technology trees

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Notice: Mongol Horse Archers and other similar units are not yet available in-game.

Other Changes

• Various bug fixes
• UI improvements
• Various system-level adjustments and refinements

Rise of Orient has only just begun.

More regional technology trees, unique units, and other changes are planned for the upcoming updates.

Thank you for playing Historia Universalis, and I hope you enjoy 0.83 — Rise of Orient I!

Hello everyone!

Here's a surprise update announcement for Historia Universalis!

Starting with the upcoming Historia Universalis 0.83 through 0.85 updates, the mod will be developed around one major theme and project.

newly main screen in 0.83

The name of this project is:

"Rise of Orient"

Here is the roadmap for the upcoming updates!

0.83 — Rise of Orient I

Release: Before August 20

What's new?

• Complete rework of the Medieval universal technology tree
• Complete rework of the Archer and Cavalry technology trees
• New Horse Archer technology tree
• Reorganization of several domestic/economic technologies
• New unique units for Goryeo and the Liao Empire
• A complete population rework for many countries across the Orient
• Several systemic changes
• Bug fixes

Some screenshots of the current 0.83 changes!

1. The entire Medieval universal technology tree has been completely reworked!

Players can now choose different development paths, including:

Archer
Horse Archer
Cavalry

This means that different civilizations will no longer necessarily develop their military technology in exactly the same way.

One of the key features is a from early technology tree divided into four distinct paths: Archers, Infantry, Cavalry, and Horse Archers.

https://preview.redd.it/bgnero64x2kh1.jpg?width=1920&format=pjpg&auto=webp&s=3c526de9c272129c032f201bfd486903e8245165

2. Population rework across most of the Orient

A large-scale population rework has been implemented across much of the Eastern world.

(India is not included in this update and will be handled separately.)

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3. New units!

A number of new units have been added, including both universal units and unique units.

New universal Unit in 0.83

0.84 — Rise of Orient II

Release: Late August

This update will introduce regional starting technology trees.

New universal technology trees will be added for:

• Eastern Europe
• India

In addition, different regions will now start with different levels and directions of technological development, including:

• Western Europe
• Russia
• Byzantine Empire
• Middle East & Central Asia
• Nomadic civilizations
• Mongolia
• East Asia
• India

The goal is to create much greater differences in AI development speed and technological direction.

Eastern European Starting Technology Tree

A new regional starting tree will be added, covering technologies from:

Axe Infantry → Viking-style Axe Infantry → Druzhina Heavy Infantry → Heavy Cavalry

These technologies will form the early technological foundation of Eastern European civilizations.

Indian Starting Technology Tree

India will receive its own starting technology tree and unique units, including War Elephants and other regionally appropriate military technologies.

Several additional systemic changes will also be included.

0.85 — Rise of Orient III

Release: Before September 12

The third part of the project will focus heavily on unique regional and civilization-specific units.

Unique units will be added for civilizations and regions including:

• Seljuk Empire
• Ghaznavid Empire
• Fatimid Caliphate
• Kara-Khanids
• Oghuz
• Cumania
• Other nomadic civilizations
• Mongol tribes
• France
• German regions
• And more

After extensive Observer testing, additional balance adjustments will also be made.

The goal of Rise of Orient

The overall goal of this project is to make the military and technological development of each region feel less uniform and much more historically distinctive.

Instead of every civilization simply following the same technology progression, different regions and cultures will have their own strengths, starting technologies, and development paths.

More regional diversity. More unique units. More meaningful technological choices.

Stay tuned for Rise of Orient!

Hope you enjoy it, and look forward to the upcoming updates!

0.82 is all about rebuilding the systems underneath the map — making great powers fight, economies matter, populations matter, and wars actually reshape the world.

This is only the foundation. 0.83 will focus on the 1066 world itself, with regional population reworks, unique military units, technology-tree differentiation, and much stronger identities for individual civilizations.

1. AI Warfare & Expansion

One of the long-standing problems in both Historia Universalis and vanilla AoH3 is that major powers rarely go to war with other major powers.

For 0.82, I focused heavily on this problem.

1) AI aggression toward weaker neighboring countries has been significantly increased.

2) Several conditions required for AI countries to prepare for and declare wars have been slightly relaxed.
Compared with vanilla AoH3, some of these values have been increased or reduced quite substantially.

3) I have been extensively testing the various conditions that influence AI war preparation.

Rather than changing only one or two obvious values, I have been testing many smaller variables individually and running observer games after each change.

For example:

AI_PREPARE_FOR_WAR_ONLY_IF_CIV_STABILITY_IS_BELOW_100

was tested through a very wide range of values:

0.134 → 0.402 → 0.001 → 1.34 → 13.4 → 0.926

This kind of trial-and-error testing is still ongoing.

4) ★ One of the biggest achievements of 0.82 was identifying and modifying a value that appears to influence how the AI evaluates the military strength of other countries.

By adjusting this value indirectly, I was finally able to significantly increase the frequency of major-power vs. major-power wars.

This value may still be adjusted in future versions depending on further observer testing.

Observer results

① In the 1440 scenario, the average number of wars during the 1500s increased to roughly 60–75 wars, and the number remained around 90 wars even during the 1630s.

② Major powers began forming much cleaner and more stable borders than before.

③ Most importantly, the Ottoman–Mamluk rivalry began naturally emerging as both powers grew.

In one observer test, the Ottomans and Mamluks fought six wars by 1716, with the Ottomans winning all six.

For the Ottoman–Mamluk conflict specifically, I plan to further encourage the Ottomans' natural historical expansion through AI and event adjustments in 0.85 or 0.90 and later.

2. AE System Rework

AE was found to be excessively restricting the long-term expansion of major powers, while a single coalition could sometimes completely destroy an otherwise successful empire.

Therefore, several AE values have been adjusted.

1) AE gained per province has been reduced to a more manageable level.
However, it is still roughly twice as high as vanilla AoH3.

2) AE generated by declaring war:

Vanilla: 7.5 → 0.81: 15.0 → 0.82: 10.0

3) ★ AE decay

After multiple observer tests, I found that AE decay appears to have a surprisingly strong relationship with the internal mechanics governing AI war activity.

Therefore, AE decay per year has been brought back to approximately the vanilla AoH3 level.

The goal is to prevent AE from completely shutting down the expansion of major powers while keeping coalitions meaningful.

3. War Score & Peace Negotiations

Capital annexation cost

PROVINCE_VALUE_CAPITAL

1.2 (0.80) → 1.0 (0.81) → 0.75 (0.82)

This was changed because smaller countries could sometimes lack enough war score to annex a one-province country.

This issue has not been completely solved yet, but the situation has improved.

Allied war contribution

WAR_SCORE_ALLIES

0.1 (vanilla) → 0.6 (0.81) → 0.8 (0.82)

This was increased because wars involving multiple fronts and many allies could sometimes result in extremely strange war-score calculations, making wars drag on indefinitely.

War reparations

The required war score and the amount of war reparations have both been reduced by roughly half.

4. Manpower System

Maximum manpower recovery time has been reduced from 25 years to 20 years.

Large wars could leave countries with almost no manpower and heavily depleted armies, resulting in extremely long recovery periods.

The change is partly a compromise between historical/strategic simulation and actual gameplay.

5. Investment & Building Balance Experiments

This version included extensive experiments comparing buildings, local manpower investment, tax-efficiency investment, and economic buildings.

During gameplay in version 0.81, I noticed that the Ottoman Empire had a very large manpower pool but surprisingly low income. This imbalance was another reason why the taxation system was reworked.

Manpower: Barracks vs. Local Manpower Investment

Testing showed that local manpower investment could be significantly more efficient than barracks in certain high-population provinces.

As a result, manpower provided by buildings was increased by approximately 50% compared with 0.8.

After testing:

Roughly speaking, local manpower investment is more efficient when local manpower is around 0–2, while buildings become more efficient beyond that point.

This was designed to make both strategies viable depending on the province.

Tax Efficiency vs. Economic Buildings

I also tested the relative efficiency of tax investment and economic buildings.

The results showed that:

• Tax-efficiency investment becomes more effective in provinces with low existing tax efficiency.
• It becomes particularly powerful in high-population, low-efficiency provinces.
• Under certain conditions, tax investment was substantially more efficient than simply constructing markets.

Therefore:

• Tax investment costs have been increased by more than 50%.
• Economic building efficiency has been increased by approximately 100%.
• Markets and food markets now provide a small amount of local tax efficiency.

The goal was to reduce the gap between investment and building-based economic development.

Example from testing

20 markets built: approximately +3.79 monthly income

Tax-efficiency investment varied greatly depending on population and existing efficiency.

In particular, provinces with:

>

showed very high returns from tax investment.

6. Unit Maintenance

As economies grew, both AI countries and players were accumulating excessive amounts of money.

I initially experimented with increasing army maintenance by around 50% depending on country rank.

After multiple rounds of testing, however, I decided to return the maintenance cost of individual units to approximately vanilla AoH3 levels.

This is because other economic systems have already been substantially strengthened:

• Commodity prices have been increased since 0.80.
• Tax income has been significantly increased since 0.80–0.82.
• Population-based income has also been increased.

Rather than making armies artificially expensive, I wanted the overall economic system to determine whether a country can sustain a large army.

7. Population Growth & Terrain Balance

Population growth

The penalties for deserts, drylands and other difficult environments were found to make long-term population investment disproportionately inefficient.

The desert population-growth penalty was therefore reduced:

-10% → -5%

The goal is to make population investment more consistently useful across different terrain types.

Terrain defense

Defensive terrain bonuses have also been increased.

This serves two purposes:

1. Improving historical/geographical realism.
2. Preventing increasingly enormous armies from making defensive terrain almost meaningless.

Current defensive bonuses:

• Plains / Steppe / Dryland: +1
• Forest / Marsh / Savanna / Semidesert: +2
• Hill: +3
• Jungle: +4
• Mountain: +5

8. Obsolete & Previously Developed Units

Previously developed units and unit types can now appear in the military recruitment interface.

This was implemented with the upcoming large-scale special unit overhaul in mind.

Special units can remain recruitable even if their technology is slightly outdated, allowing historically distinctive units to remain relevant rather than disappearing immediately when a new military technology is researched.

9. Population as a Core Economic Foundation

Around 1650, I noticed that repeated wars between the Ottomans and Mamluks could leave their economies at roughly one-third of the economic strength of countries such as Qara Qoyunlu and France.

I therefore increased the contribution of population to national income.

BASE_INCOME_POPULATION_INCOME

0.1 → 0.2

Population-based income is now twice as strong as in 0.80.

This means that highly populated countries have a stronger economic foundation and can recover their economic strength over the long term.

This change also became particularly important after returning unit maintenance closer to vanilla levels.

10. 1060 Scenario Balance

Observer testing of the 1060 scenario revealed a major balance issue:

The Byzantine Empire was sometimes able to defeat a combined force of the Fatimids, Seljuks and Ghaznavids and expand far beyond what I considered reasonable for the scenario.

As a result, I decided to begin a historical population rework of several major powers, including:

• Fatimids
• Seljuks
• Ghaznavids
• Liao
• Goryeo
• and other major powers in the region

This work will continue into the upcoming 0.83 — Rise of 1066 update.

11. Miscellaneous

Nomadic governments

The maximum number of loans for nomadic governments was adjusted:

-1 → -5

This was done to keep the loan limit proportional to the increased number of loans available since 0.80.

Population Rework

The population values of Timur and his subject states were reworked in 0.82 based on historical population estimates.

12. Special & Unique Units

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New Special & Unique Units will begin to appear starting with version 0.82.

In 0.82, the Ottoman Janissaries have been added as the first unique unit.

The Janissaries were initially given a relatively high maintenance cost to reflect their status as an elite military unit. However, this was later reduced for two reasons: the economic difficulties observed in the Ottoman AI during testing, and the historical fact that the Janissary corps was largely composed of slaves and the sons of prominent families, who were trained and maintained as part of the Ottoman state military system.
The goal is to preserve the Janissaries' role as a distinctive elite force without making their maintenance cost excessively burdensome for the Ottoman economy.

Coming Early Next Week - Rise of 1066 -

Historia Universalis 0.83 -Rise of 1066 -
A major update is coming, bringing new historical units, military changes, and extensive balance improvements to the 1066 scenario.

More details soon!

Hello everyone!

There’s a big surprise coming with Historia Universalis 0.82!

★ So, what’s the surprise?

The Ottoman Empire will be getting its own unique unit: the Janissaries!

This is especially meaningful for Historia Universalis because I’ve found a way to work around one of the limitations of AoH3: adding historically unique units to specific countries.

The Janissaries are just the beginning. I hope this will make Historia Universalis feel even more historical and immersive, with different nations developing their own military traditions and unique forces.

I hope this gives you another reason to dive deeper into history through Historia Universalis!

Stay tuned for the 0.82 update! !

Here is some Screen Shot!! ↓↓↓

Janissaries tech tree

training Janissaries troop

Hello~ everyone!
Here are the main changes in Historia Universalis 0.81.

This update focuses mainly on military balance, AI economy, diplomacy, AE, terrain, and the first stage of the historical population system.

As always, many of these changes are still being tested through observer games, so some values may be adjusted again in future versions.

★ 1. Advisor Manpower Effect ×3

The manpower effect of advisors has been increased threefold.

Since Historia Universalis significantly increases overall manpower compared to vanilla AoH3, advisor manpower bonuses also needed to be increased to remain meaningful.

★ 2. Army Destruction Threshold: 10% → 5%

The threshold at which an army is completely destroyed in battle has been reduced from 1/10 to 1/20 of its original strength.

With the previous 10% threshold, armies could disappear too easily during large battles. I felt this was harmful to gameplay, especially in large-scale wars, so the threshold has been lowered.

★ 3. Battle Duration Increased by 50%

Battle duration has been increased by approximately 50%.

Historically, individual battles often lasted only several days to around a week. However, from a gameplay perspective, I found that battles lasting roughly 15–30 days create more opportunities for reinforcements to arrive.

The goal is to make major battles feel larger and more dramatic, rather than having armies instantly destroy each other before nearby forces can intervene.

★ 4. AI Investment in Local Manpower Greatly Increased

The AI's tendency to invest in local manpower has been significantly increased.
This is still under active testing.

Vanilla AoH3 has a long-standing issue where local manpower is heavily concentrated in Europe and parts of the Middle East. Even if historical population changes are introduced later, this existing imbalance would still remain.

To reduce the gap between regions with high local manpower and regions without it, the AI now invests much more heavily in local manpower.

The coefficient controlling the difference in local manpower investment costs has also been increased. The vanilla value was 10.0, while Historia is currently testing values up to 30.0.

This is intended to reduce the extreme military imbalance between different regions.

For example, during a 0.81 observer test, Castile reached over 40 million population and more than 10 million manpower by 1840, which clearly showed that the system needed further adjustment.

This system is still experimental and may change significantly.

★ 5. Relation Improvement Advantage Growth ×2

The growth rate of the Relation Improvement advantage has been doubled.

Compared with other national advantages, I felt that this option provided too little benefit. Since diplomatic points became considerably more valuable in Historia 0.80, I wanted diplomatic advantages to have a more meaningful impact.

★ 6. Population Growth Rate per Population Reduced by 50%

The population growth rate has been reduced by 50%.

From version 0.81 onward, historical population data will gradually be introduced into the mod. Since this can naturally lead to much larger population numbers, population growth also needs to be slower to prevent excessive population explosion later in the game.

★ 7. Allied War Contribution ×5

During wars involving allies, the war score value generated by territory occupied by an ally has been increased fivefold.

Five times may sound extremely high, but this is roughly equivalent to half the contribution of the war leader.

The goal is to make allied participation more meaningful instead of allowing the war leader to receive almost all of the territorial contribution.

★ 8. Population-Based Taxation Rebalanced

After extensive testing, I found a taxation balance that allows large states to maintain large armies while still keeping taxation as a major part of the economy.

Tax revenue now accounts for roughly 50–60% of total income in many cases.

I felt this produced a more convincing medieval/early-modern economic structure, so this value has been adopted for the current version.

★ 9. Horse Archer Maintenance Bug Fixed

Horse archer maintenance was incorrectly set to 5× the default value instead of the intended 1/2 of the 0.80 value.

This has now been fixed.

In 0.80, this bug could cause severe financial problems when horse archers became available before 1500, suddenly putting both the player and AI under heavy economic pressure.

★ 10. AI Friendly-Country Recognition Reduced: 6 → 4

The AI now recognizes only 4 friendly countries instead of 6.

This also means that the player is less likely to automatically be included among the countries considered "friendly" by the AI.

The goal is to make AI diplomacy less predictable and reduce excessive diplomatic favoritism.

★ 11. Major Power Military Maintenance Penalty: 15% → 10%

The military maintenance penalty applied to Major Power level civilizations has been slightly reduced from 15% to 10%.

The intention is to give major powers a better chance to resist large empires and prevent empires from becoming too dominant simply because of their scale.

★ 12. Core Creation Cost Restored

The temporarily reduced core creation cost from version 0.80 has been restored to the vanilla value.

This change was made partly because fixing the horse archer maintenance bug significantly reduced military expenses, creating more room in the economy.

Core creation and religious conversion costs may be increased further in future versions depending on economic testing.

★ 13. AI-Only Military Maintenance Reduced by ~23%

AI-only military maintenance costs have been reduced by approximately 23%.

This modifier does not apply to the player.

The purpose is to make the game slightly more challenging for the player by allowing the AI to maintain larger military forces.

However, the global economy in the current 0.81 version is relatively prosperous, so this value may be adjusted again depending on future economic testing.

★ 14. AI AE Thresholds Adjusted

The AE threshold at which the AI considers itself relatively safe, as well as the maximum AE at which it begins preparing for war, has been relaxed.

This temporarily brings these values closer to vanilla levels.

However, there is still a major difference from vanilla: AE generated per province is approximately 3× higher.

Therefore, AE pressure on both the player and AI remains significant.

This adjustment was made based on dedicated observer-game testing and is still being evaluated.

★ 15. War Reparations & Vassalization Score Requirements ×2

The score required to receive war reparations or vassalize an opponent was considered too low, so both have been increased by 2×.

Even after this increase, these requirements are still somewhat more forgiving than vanilla when viewed comparatively.

★ 16. Peace Treaty Gold +50%

The amount of gold that can be taken through peace treaties has been increased by 50% compared with version 0.80.

This was done to reduce the economic gap between taking war reparations and taking direct monetary compensation through peace treaties.

★ 17. Terrain Combat Modifiers Increased

Terrain penalties for attackers — or, effectively, defensive advantages — have been increased.

One of the problems I have noticed in testing is that the player generally makes much better tactical decisions than the AI during battles. Because of this, I wanted terrain to provide stronger defensive advantages.

I also wanted terrain to represent logistics, weather, and geography more realistically.

The current values are:

• Plains / Steppe: +1 Defense
• Semi-desert / Desert / Forest / Savannah / Swamp: +2 Defense
• Hills / Tundra / Taiga / Jungle: +3 Defense
• Mountains: +4 Defense

These values are not necessarily final and may continue to change through observer testing.

★ 18. AE Expansion Penalty Adjusted: 15 → 10

Testing showed that AE was becoming too significant an obstacle to expansion for major powers.

Therefore, some AE-related values have been relaxed from 15 → 10.

For comparison, the vanilla value is 8.

The intention is not to remove AE pressure, but to prevent it from completely blocking the expansion of large states.

★ 19. Historical Population Data Expanded

A new historical population system has been introduced using population data from approximately 1450–1500, together with my own method of applying the data to the game.

For version 0.81, Chagatai Khanate and Yarkand have been added.

The historical population system will be gradually expanded and updated with each version.

This is only the beginning of the larger historical population system planned for Historia Universalis.

https://preview.redd.it/5l4mdgyamcih1.jpg?width=1920&format=pjpg&auto=webp&s=682599dfab14b7e1d57dcf943ea9a045eb9f91ba

A few notes

Many of these changes are based on observer-game testing, and some systems — particularly AI manpower investment, AE behavior, terrain combat, and the economy — are still being actively tested.

So please don't consider every number above final. Some values may change in future versions as more large-scale tests are completed.

Thanks for playing and for all the feedback!

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Philosophy

I started playing Europa Universalis III in 2008, and since 2015 I have spent more than ten years playing Europa Universalis IV, accumulating over 3,000 hours of playtime.

During those years, I often asked myself a simple question: "Can a grand strategy game be both historically immersive and dynamically engaging?" In 2022, that question led me to spend eight months developing a private EU4 Historia mod as an experiment.

In 2026, I played Age of History III for the first time. I immediately appreciated its clean interface, fast pace, and accessibility. However, after spending more time with the game, I felt that some of its underlying systems lacked the depth and historical dynamism that I personally enjoy in grand strategy games.

After several dozen hours, an idea naturally came to me: what if I recreated the Historia philosophy in Age of History III? My goal was not to turn AoH3 into EU4, but to preserve its simplicity and casual pace while enriching its strategic depth.

About a month later, after becoming completely absorbed in modding, I decided that even an unfinished project deserved to be shared with the community rather than remain on my hard drive. That decision became the first public release of Historia Universalis, now available as Version 0.8 Beta.

Historia Universalis is my attempt to combine historical plausibility with dynamic gameplay, inspired by the design philosophy of EU4 while embracing the simplicity and accessibility of Age of History III.

What's New? (Version 0.81)

1. Historical Population Rework – Building a More Believable World

One of the biggest changes in Historia Universalis is a complete rework of the population system.

Historical population values have been reworked across Central Asia, Mongolia, Xinjiang, Tibet, and Ming China, with the goal of creating a more believable demographic balance based on historical records.

Although population in Age of History III does not directly determine manpower, it has a significant impact on tax income, which in turn indirectly affects military strength and long-term national development.

Because of this, population is no longer just a number—it has become an important part of both historical immersion and gameplay balance.

For balance reasons, some civilizations (such as Ming) currently use reduced historical population values instead of their full historical estimates.

Figure 1.1. For gameplay balance, Ming currently uses approximately 50% of its historical population.

Figure 1.2. Oirat at the start of the 1440 scenario after the population rework.

Figure 1.3. Population ranking in Historia Universalis (1493)

2. Large-Scale Warfare Inspired by Early Modern History

One of my design goals was to make wars feel worthy of great empires.

Both AI and players can now build powerful states capable of fielding much larger armies than in vanilla. Instead of a few isolated battles, conflicts evolve into prolonged campaigns involving multiple fronts and massive military movements.

The result is a more dynamic battlefield where the rise and fall of empires feels much closer to the scale of real history.

Figure 2.1. The Ottoman Empire launching a large-scale invasion of Wallachia.

Figure 2.2. The campaign ended in a decisive Ottoman victory.

3. A Living System, Not Just Balance Changes

Historia Universalis is not built around a few isolated balance changes. Instead, almost every major gameplay system has been reworked to interact with one another.

Some of the major changes include:

• Reduced army maintenance and a stronger economy to support larger, historically scaled armies.
• Rebalanced trade goods, giving different regions more distinct economic identities and strategic value.
• Improved terrain bonuses, more realistic siege pacing, and broader battlefield mechanics. Rather than focusing on micro-level combat mechanics, the mod emphasizes strategic and operational warfare.
• A heavily revised Aggressive Expansion (AE) system, slowing excessive snowballing while still allowing both players and AI to build powerful empires under the right circumstances.
• Extensive changes to politics, economy, domestic management, diplomacy, military systems, buildings, Legacies, and Advantages.

Rather than functioning as isolated mechanics, these systems are designed to influence one another, creating a more dynamic and interconnected grand strategy experience.

4. Conclusion

Historia Universalis is a project that aims to combine historical plausibility with engaging gameplay.

Although inspired by Europa Universalis IV, this mod is not intended to recreate EU4 inside Age of History III. Instead, it seeks to preserve the simplicity and accessibility of AoH3 while expanding its historical depth and strategic possibilities.

The current public release is Version 0.81 Beta, and development is still ongoing. Major updates are already planned for Version 0.90 and Version 1.0, with additional historical content, gameplay systems, and balance improvements.

Thank you for taking the time to read this first Dev Diary. I hope you enjoy following the development of Historia Universalis, and I truly appreciate any feedback or suggestions from the community.

5. Please note:

• Historia Universalis is currently in Beta.

Some gameplay systems are still being balanced and refined.

• Colonization is currently disabled.

It will be introduced once the historical balance and overall gameplay have reached a more stable state.

• Map graphics

Some screenshots in this post use the Soft Relief Map Mod.

This visual improvement is not included in Historia Universalis.

Special thanks to the creator of the Soft Relief Map Mod for their excellent work.