Aug 31, 2022

Hearts of Iron IV - PDX Katten

Greetings all,

Today we have quite a number of items for the dev diary. We’ll be covering some new additions to the career profile system, followed by some new tools coming for modders in the Avalanche update.

To begin with, I’ll hand over to our designer on the career profile:

Hello!

Ingevar here with an update regarding new features coming to the Career Profile.
Since the release of Career Profile earlier this year we've been working on the next iteration that will bring more stats, non-ironman achievements, and some profile customization.

Let's look at it in detail.

Playthrough Overview

When BBA is released, every player will find the playthrough overview available in the ESC menu when playing the game.

This familiar window will contain some numbers for your current playthrough, including new stats and awards.

New Stats

We are adding more stats to track combat efficiency like the amount of offensive and defensive battles, the ratio between them, or the ratio of battles versus encircled divisions. We want these stats to be a better depiction of each player's playstyle and will continue to add more, so if you have any suggestions, please tell us in the comments.

Stats for Modded Games

Previously we gathered numbers only from the vanilla version of the game, but now we've added a separate set of data for games played with mods.

Both base game and modded games stats are working in single-player games, at least for now. We are looking into making MP counts as well, so stay tuned for future updates on that topic.

Awards

Awards are medals and ribbons: new kinds of in-game achievement that don't require you to play in Ironman mode.

Medals have three grades: bronze, silver, and gold. Each grade is harder to get than the previous one, with the aim that bronze is something you can get just by playing the game, while gold will require a dedicated effort and might not be achieved from the first try even by the most experienced players.

Ribbons have no grades, but the difficulty is there for most of them.

Awards won't work with most mods, cause you can never predict what the mod changes and therefore if the award required any challenge at all.

At the same time, we know that mods are an essential part of the HoI experience, so together with the base feature, we're introducing support for modded awards.
Any modder will be able to use all existing UIs for creating a list of unique awards that can be tracked, awarded in the game, and then displayed in the Career Profile.

Profile Customization

Every grade of medal you get and every ribbon will also award you with some Career Points.

Career Points are used to unlock Profile Pictures.

Some Pictures are unlocked after you get one or two medals, but others will be available only to players who dedicate a substantial amount of effort to getting lots of gold medals.

Friends

All this comes together in the last feature I'd like to show today.

We're adding a Friends list to the game. You'll be able to find it in the main menu when BBA is out.

Friends window will have all your friends from Steam or Xbox and for now will only be used as a shortcut to viewing each other's Career Profiles.

By default, every profile in the game will be viewable by all your friends, but you can choose to make it private, this option will be available right in the Career Profile window.

TL;DR

All these features will be released together with the avalanche update. So any player who has the base game will be able to access Playthrough Overview, Awards, set their Profile Pictures, or view the Friends list.

The story of Career Profile just starts here and we plan to add more awards, stats, and profile customization to the game based on the feedback we get from you.
Hope you like this when it's out.

Modding In-Game Achievements

One of our new features for modders is a system to support custom achievements.

The feature aims :

to allow mods to define their own achievements
to display them and their completion status in-game
to save them when a player completes them so that they appear as achieved when starting a new game

Hard limitations :

the achievements will not be displayed on steam (or other stores)
no way to know the completion rate among players

We have joined forces with Red King and their career profile to present those achievements in the prettiest way. Also the new Ribbon system will allow modders to easily illustrate their achievement without any graphic skill ! Of course if you are a master of the 64x64p icon, you can emulate our classic achievement illustration.

The Awards screen with mod achievements. Icons or ribbons, the choice is yours.

A sample of script to define achievements

Behind the scenes, these achievements are earned and stored based on the game’s modset. Modifying the modset should clear achievements, but if the modset remains constant, any achievements earned will be persistent to that combination of mods.

Unit Medals and Units

Arheo back now to go over some more details on the script accessibility for our new features.

As mentioned briefly last week, unit medals are being added in BBA. These are fully scriptable, and take a similar form to regular database objects you’ll be used to working with.

Since the modifiers that can be applied via medals take a different path to regular modifiers, the list of possibilities is somewhat shorter than in other modifier scopes.

We’ve added a list of options at the top of the medals file, though we’re open to future suggestions if you find yourselves in need of something new:

You’ll note that the leader modifier is unused in the vanilla game. This modifier will translate over to army generals if the leader is promoted, and exert effects on the entire army.

The one_time_effect field will run an effect in the unit scope, though you should be able to scope to a unit’s owner and run effects on a country from this block.

Working with units is, as previously mentioned, new to script in the avalanche update. For the time being, only army units are accessible through script, though this may be expanded upon in future updates. The following effects will be available to you:

random_country_division
every_country_division
random_state_division
every_state_division
reseed_division_commander
destroy_unit
add_history_entry
change_division_template
add_unit_medal_to_latest_entry #usually used in combination with add_history_entry, otherwise you may not guarantee a valid entry.
add_divisional_commander_xp

Combined with the following unit conditions:

any_country_division
any_state_division
division_has_majority_template
unit_strength
unit_organization
is_unit_template_reserves
division_has_battalion_in_template

Balance of Power

The Balance of Power feature is built in a way that makes it extremely flexible, and therefore probably very useful for modders. Any given country can only have one Balance of Power at any given time - but there’s nothing stopping you from having several that you switch between as things evolve.

The definition might seem a bit tricky at first, but that’s only because it is extremely flexible. It starts like this:

This example is from Ethiopia - you set the id of the Balance of Power, the starting position, and the two starting sides. The sides are defined further down, and you can replace them with other pre-defined sides using script. This means you can, instead of changing the entire Balance of Power, just replace one, or both, of the sides should you want to do that instead.

You also define a decision category as the Balance of Power category, meaning that you can script Balance of Power decisions the same way as you would script normal decisions. The will then appear in the Balance of Power UI. So basically anything you can do with decisions, you can do in the Balance of Power UI…

Each side is further divided into ranges with a min and max value, and a set of modifiers that are active when you are in this range. Again, the ranges are customizable, so you can have basically as many or as few as you like (within reason).

As you can see from this example you can also run effects when the range becomes active or when the balance shifts away from it.

You can also set/change the graphics of the side as you like:

What else? Well you have triggers based on the Balance of Power, so you can lock Focuses, decisions, events, or whatever behind the Balance of Power being at a certain level. You can modify the balance either with one off values or with a ticking score. And you can of course remove it altogether.

In all I expect to see some wonderful applications of this in mods going forward.

Peace Conferences

Peace conference modding has now become somewhat simpler, as well as being more consistent with the rest of the game’s scripting standards albeit at the cost of some rather verbose dotscoping chains.

Peace conferences now primarily work on a per-state basis, with the exception of ships and stacked bids (which due to technical limitations are not very accessible to script).

Every turn, each state will be subject to two evaluations for the country from whose perspective you are playing or viewing. The first evaluation will define the bidding cost per action type for a state, and the second will define the ai desire to bid on said state. These two values do not correspond, but are affected by each other.

In the entry above, this cost multiplier will be applied at point of bidding for a country that is either NOT puppeted, or is bidding for itself, to states which are their cores.

You can add categories here which will consolidate their values in the tooltip for that state during a peace conference. This cost multiplier will only work on bids of the ‘take states’ type, but multipliers can be made to affect any combination of bid types if treated as an array.

A state can be subject to multiple cost reductions, which stack multiplicatively.

The evaluation of AI desire works in a very similar way:

Instead of affecting the cost, this affects the ai’s subsequent evaluation of the cost when deciding what to bid on. Here, the AI is subject to a -75% desire to liberate tags that belong to the is_unlikely_country_tag scripted trigger. In short, it means the AI will prefer not to release certain wacky, wonderful tags. AI desire can also be subject to multiple modifier entries, and these will also stack.

The AI evaluates costs with a bucketed per-type approach, rather than simply bidding on the best cost*desire entries. This goes some of the way towards reducing bordergore, and effectively takes a sample of the desire of bids of the same type and target - France for example, would consider all Puppet Switzerland bids to be of the same value to try and avoid leaving holes.

Debugging Tools

We’ve expanded the options in our imgui during By Blood Alone, and now this handy air region tool will be in your hands:

You can access this with the console command imgui show air, followed by selecting an air region. This will give you up-to-date information on the details of the wings present in the area and their efficacy.

—

And that’s all for this week! Next week there will be a break in dev diaries, but tune in in two weeks for a round up on the technical situation and changes coming in the Avalanche update.

/Arheo

Aug 24, 2022

Developer Diary | Quality of Life Improvements

Hearts of Iron IV - PDX Katten

Greetings all,

Due to a misplaced carrier pigeon, today’s dev diary will not be on modding changes, but will instead focus on a variety of minor and QoL changes coming in the Avalanche patch accompanying By Blood Alone.

This list is by no means exhaustive: we’ll cover the more impactful changes here and still give you plenty of juicy items to discover in the patch notes.

Armor Piercing

Those of you who routinely peruse the forums may have noticed me discussing details on our change to the piercing formula, but it serves to draw attention to it here, in a more visible light.

In the Avalanche update, we’re reworking the binary nature of the piercing vs armor calculation to act in a somewhat more realistic way, as well as to make designing your divisions and equipment a little more nuanced.

Prior to BBA, the damage of divisions making attacks against an armored target would be reduced by 50% if their piercing stat was less than the armor value of the target. In BBA, the thresholds described above will be in play.

There have been some minor changes to piercing values on equipment, but we intend to avoid making any major changes here until we see the effect of this change on player habits. Any balance changes will of course be applied in our regular patching schedule.

Piercing also plays an important role in naval combat, and we haven’t forgotten about it here. In naval combat, the piercing vs armor mechanic affects the critical hit chance (simulating penetration hits) of individual naval guns against a target, and we’ve added the following thresholds:

You’ll notice we’ve added an extra threshold here. This goes some of the way towards simulating extreme overmatching, and brings a small extra potential bonus for super heavy guns (assuming you hit what you’re aiming at).

These values can of course be modded, and support the addition of new thresholds for those in need of atypical or more gradual curves.

Design Comparison

The ship, tank, and plane designers now have access to an additional tool when designing equipment:

This comparison window allows you to select a variant to compare against the variant you are designing. The comparison variant does not need to have the same equipment type as the one you are designing, and assists in the creation of specialized variants with a frame of reference. The stats comparison markers are displayed in context to the design you are editing:

Here, we’re comparing the German starting heavy tank to the Panzer II light tank.

You can select a comparison variant from among any types you own or have licensed or captured, and for owners of La Resistance from among any countries which you have matched the highest corresponding intelligence tier for.

In short, this gives you a tool with which to plan your designs in order to counter your opponents’ equipment.

War Support

In Avalanche, we’re making some significant changes to war support. Over the course of the game’s lifespan, war support has gradually plummeted in terms of relevance both due to power creep in country content (something we’re starting to take an active interest in addressing in general), and due to the ease of trading in political power thanks to war propaganda.

War support is intended to serve as an abstraction of a population’s willingness and capability to engage in the war effort, on a military and civilian level. As such, war support has one important new effect:

Note we have also improved the tooltip for war support and stability to include the base value plus any changes from events and focuses.

While at war, war support has a scaling negative effect on the stability of a country, simulating the dissatisfaction of the civilian population at the predicament they have been placed in. War support is now something you will need to care about during a war, and further changes have been made to accentuate this:

All sources of ticking war support (weekly) have been removed or changed into flat bonuses.
Taking casualties during war will now contribute to a gradual ticking war support malus replacing the malus that was previously only used by abilities such as Force Attack.
The war support malus from strategic bombing has rebalanced to be in line with the above.
The war support malus from sunk convoys has been rebalanced to be in line with the above

The three components described above are now the main sources of reduced war support while at war, and give you a strategic reason to pace offensives and conduct campaigns in an intelligent manner.

‘Infinite’ war propaganda decisions have now been removed. This was a trivial way to increase war support in the mid-late game, and combined with the availability of political power, resulted in very little meaningful way to reduce a target nation’s war support.

Instead of war propaganda against countries, war support decisions now target one of the three main maluses:

These decisions will offset the maximum negative trend of each of the three negative components, and gradually increase it to a maximum of zero. In short, war support can no longer be arbitrarily increased outside of focuses, events, and unique decisions - it must instead be managed.

As you will note, the base, generic war propaganda decision currently remains, but may only be used to increase war support if below 50%.

This is a significant change we will continue to monitor, but we are happy with the results we’ve seen so far.

Armored Trains and Logistics Strike

Since the release of NSB, we (and many of you) felt that the Logistics Strike air mission was too strong. This is, in part, due to an oversight which did not apply state-level AA disruption effects to it - this has been fixed.

Correspondingly, a further issue with armored trains has been fixed, meaning that they will once again be vulnerable to damage from Logistics Strike, albeit at a much reduced rate compared to other varieties of train.

However, to further balance this out versus the current live version, armored trains have now learned to use their AA guns:

We previously decided against this approach due to the relatively minor impact that armored train AA had on the grander aviation situation in the war, however thanks to the ministrations of one of our excellent coders, we have arrived at a solution whereby armored trains will only inflict damage to planes actively attacking them on a logistics strike mission. You will be able to track this explicitly in the air region details menu:

AI Tank Strategy

You should now notice a somewhat more sensible use of armored divisions by the AI. The AI can now be encouraged to use tank divisions on any particular frontline, and we have added some generic situation triggers to make this happen more regularly.

Note this does not yet translate to using tanks in the same sort of pincer-encirclement that players tend to use. This is a notably non-trivial problem to solve, but is on our wishlist for future investigation.

Allied Logistics

You will now be able to open the logistics menu for subjects and faction members through the diplomacy menu. This gives you a better real-time view of your allies’ equipment situation, and helps plan a better lend-lease strategy:

It goes without saying that any actions usually available through this menu (destroy equipment et al) will be locked for observing countries. While we toyed with the idea of making this available based on intel, this proved to be far too powerful a tool in the wrong hands.

Aug 23, 2022

Barbarossa 1.11.13 - Nakama Crossplay - Checksum d173

Hearts of Iron IV - PDX Katten

Hello everyone!

We just released patch 1.11.13 for "Barbarossa" on Steam and Microsoft Store. The new checksum is d173.
This update introduces the possibility to play multiplayer games across stores (such as Steam and Microsoft Store) using the Nakama network solution already in use in other PDS titles. See the FAQ below for more details.

Saves made with 1.11.12 are expected to be fully compatible with 1.11.13 and you can continue your previous game.

If you discover any bugs in patch 1.11.13, first check the known issues list, and if necessary please report them in the bug report forum as usual.

Nakama Crossplay FAQ

What is Nakama Crossplay?

Nakama is a network solution that is independent of the store you bought the game on (be it Steam or Microsoft Store) and allows you to play with your friends regardless of where they have the game.

Does it replace the current network layer?

Nakama does replace the current solution (PDX MP) on Microsoft Store, but on Steam it is an optional alternative you have to select when launching the game. By default the game will behave exactly like it did in the previous release on Steam.

How does Nakama compare to Steam MP?

First and foremost, Nakama allows you to play across game stores, something our current implementation of Steam MP is unable to do. Secondly, it does not rely on direct connection, meaning it makes it impossible for clients to know the real IP address of the host (and vice versa). This comes at the cost of some extra latency, so depending on where the players are located in given MP session you may experience higher ping than with Steam MP.

How do I enable Nakama MP?

Nakama is always enabled on Microsoft Store. On Steam, you will get prompted to select if you want to start with Steam MP or Nakama MP when launching the game. Starting with the first two options will start the game with Steam MP as usual.

Once in the game, you can tell which version was used by looking at the bottom of the main menu. The letter (S) or (N) after the checksum tells you whether you are using (S)team or (N)akama.

Why does the game ask for a Paradox Account to play with Nakama?

The matchmaking service needs to be able to identify players across game stores, so we cannot effectively use your Steam or Microsoft Store ID. Instead, we rely on your Paradox Account user to be able to host, view and join other players’ games.

Patch 1.11.13 (d173) - FULL PATCH NOTES

################################################################
######## Patch 1.11.13 "Barbarossa" #########
################################################################

##################################
# Free Features and Important
##################################

- Nakama MP is now available

Aug 17, 2022

Developer Diary | Peace Conference Roundup

Hearts of Iron IV - PDX Katten

Hello all!
I join you to once again talk about peace conferences. This time we have more info on our changes and features that I was not able to go into last time. Most of these are coming as part of By Blood Alone.

Previously I talked about mostly the structure of the new Peace Conference system. If you have not read that Dev Diary, I recommend checking that out first. The short version is that we are reworking the old peace system into a new one that features simultaneous and blind turns, all conferences actions being contestable, and limited points to use in the conference.

Before we cover new stuff I also want to address some changes to the jargon we introduced last time. We considered changing “demands” to “bids” to fit with the new system. The previous dev diary talked at length about bids. We are instead now referring to all of these as “demands.”

Now for some new stuff! Firstly, I would like to show off our nearly complete UI with a comparison to the old UI.

Nearly Finished PC UI

Old PC UI

In the new system we have expanded the “Demands” portion to the entire left of the UI while moving all relevant information about victors or beneficiary nations to the right. Part of this was to make the menu more presentable, but another part of this was to handle what is now a more complex system of demands.

As part of By Blood Alone, we are adding five new types of demands to the peace conference. Four of these are a new type of “Additional Demand” which I will go into shortly. The other new demand is “Take Navy.” This will allow participants in the conference to use their participation points to demand enemy capitol ships as they would a single state. This means that players requesting the same ship will result in a contested claim. When the conference finishes, screen ships will be divided up amongst those who claimed capital ships based upon the ratio of capital ship industrial cost claimed. We attempted to find solutions to allow more precise claiming of non-capital ships, but were unable to arrive at a satisfactory interaction flow or a good way to fit it into the larger peace conference system.

Naval Demands being issued for the mighty Scharnhorst

As mentioned previously, we now have “Additional Demands” These options all require an underlying demand of puppet or change government to have been applied to a state first. Secondary demands can be applied over the top of a normal demand during the same turn or any subsequent turn.

The first secondary demand we have is “Demilitirized Zone.” this prevents the target nation from placing troops in the selected state. This is a pretty classic part of many historical peace conferences and serves as a way of keeping troops off of borders.

DMZ option

The next two secondary demands are both economic. These are “Resource Rights” and “War Reparations.” To make resolving contested demands fit into our system, both of these demands target single states. Resource Rights gives access to the resources in a state. War Reparations gives control of local civilian factories in a state. Both of these last for a period of time the length of which is still TBD.

Resource Rights and War Reprations options

Our final new demand, coming with BBA, is “Dismantle Military Industry.” This will remove military factories from the targeted state. This can be used to tear down a heavily militarized state’s mic and help slow down re-militarization postwar.

Dismantle Miltiary Option

That’s all we have for today and I thank you for stopping by. Next week, we will be talking about modding. Stay tuned! o7

Aug 10, 2022

Developer Diary | Division Commanders & Unit Medals

Hearts of Iron IV - PDX Katten

Greetings all!

Welcome back to today’s feature dev diary on a series of interconnected subsystems being added to the game in By Blood Alone.

One of the major points in my first roadmap dev diary was that I felt quite strongly about the inclusion of further roleplay and immersive elements in Hearts of Iron. What I’ll be showing off today is intended to fulfill a small part of this bullet point.

Those of you with keen memories will recall an early teaser I posted here. Some of you guessed correctly, and in BBA, we’ve introduced a dynamic system for naming battleplans. For many major nations, battleplan names can be provided through a list of locations, resulting in a historical series of operation tags which will be applied when plans are created:

Of course, the war does not always proceed historically, and battleplan names can also be generated from several component lists for instances where a historical variant cannot be found. These name lists are fully moddable, and can be unique to countries. In some cases (ie; Soviet Union) a different naming convention can be utilized to represent the somewhat uninventive approach to naming operations that was used in reality:

Naturally, in the spirit of roleplaying, these operation names can be modified in-game, and you can replace the text with whatever operation name you desire. This will apply to any sub-orders derived from the initial drawn line:

If unset, naval landing and paradrop orders will have a unique pattern to remain unique.

This system however, goes further than a simple naming convention, and ties into another addition being made to BBA.

Division Commanders

In BBA, we’re replacing the standard method of recruiting new generals out of thin air. Instead, every division will be created with a commanding officer upon game start, or when they are trained:

These are predominantly generated from country-specific namelists, however in some cases we have set these individually for starting divisions. When a new unit is created, they will be provided a randomly generated character name and portrait. To accommodate the increased use of generic portraits for these, we’ll be adding a large quantity of additional generic portraits for owners of BBA. The work involved in creating these is not insignificant, so for now we’ve limited ourselves in adding portraits to major nations only.

You’ll be able to get an overview of all division commanders in your army within the officer corps screen:

In an effort to avoid unnecessary micromanagement, we’ve made a few important decisions. Division commanders themselves will not directly confer bonuses upon the divisions they command, however the divisions they command will now earn and log a record of important actions they may perform during the natural course of a campaign:

Important actions such as taking a capital, securing a high-value victory point, and more, constitute actions for which a unit can be awarded a medal. It is expected that over the course of a campaign, many units will qualify for receiving medals, often several - the system is not driven by scarcity, as we do not intend for players to micromanage individual actions, rather to manage the macro-level step of choosing when and what to award their units.

As mentioned above, division commanders will not explicitly confer bonuses, however the medals awarded for action will. Medals are intended to act as a pp sink for the mid-late game, as we find a lot of players tend to end up with a significant amount of this resource as decisions, advisors and focuses begin to dwindle.

Units can receive multiple medals, however the cost for each will increase as more are granted to any given unit, and the effect of stacking specific medals will decrease per instance of the same effect.

As you will note above, medals can be specific to countries, and we’ve included a series of generic medals based on alignment, as well as unique medal sets for each major country. A medal’s effects will only extend to the unit it belongs to.

A medal’s name and description will in most cases be dynamic depending on what action it was awarded for, and extreme valor while on a specific named operation can also result in receiving a medal for that action.

To further streamline the process of awarding medals, you can perform quick actions to do this through the officers entry in the corps screen:

As mentioned previously, we’re removing the old method of recruiting generals by means of reaching into the void and plucking out a fully qualified officer. This means that your army generals will now be directly linked to your field of divisional officers, and their capability directly linked to their actions in the field.

Divisional officers will store experience based on the experience gain of the unit they are commanding, as well as receiving a lump-sum when a medal is awarded. While active as a divisional officer, this experience will have no meaningful effect, however, when in need of a new army general, you can promote divisional commanders out of their divisional role and directly into their new role as a general.

Any medals awarded to the division will be retained by that division, however, the newly created general will keep a reference to their awarded medals as a means of remembering their accomplishments in the line of duty (albeit with no direct effect on their new army - although we’ve elected to support this behavior for modders should they wish):

When a divisional officer is promoted this way, the experience they have earned during the course of their field command will be applied to their experience level as a general (up to a maximum cap). Promoting someone with field experience can prove a lot more valuable than hiring another pen-pusher, after all. If they have earned at least a certain quantity (as yet undecided) of field experience, they will also begin with a personality trait corresponding to the type of division they were commanding (armor officer, infantry officer, etc).

Unit Cohesion

You will also note that my roadmap included a wish to improve the battle-planner. While this is likely to be a slow, iterative process, BBA heralds the inclusion of a new frontline parameter intended for advanced users.

The Cohesion parameter can be set on any root frontline order, and will affect how the unit controller places divisions across that frontline. The default setting of ‘Flexible Cohesion’ functions as you have grown to expect - all units will be evaluated for placement suitability and potentially relocated to fill perceived gaps in frontline cohesion.

Balanced Cohesion’ will only successfully evaluate units that are within a defined distance from the target (distances are moddable). In practice, this results in less unit shuffling along frontlines, but should still ensure that frontlines respond to changes in size and shape.

The final setting, ‘Rigid Cohesion’ is intended primarily for long defensive lines, and will only successfully evaluate unit positions that are within a very short distance from the target location. In practice this results in relocations only taking place to neighboring provinces, and can result in gaps being created in frontlines if left unattended. It is expected that this setting will be used by players who primarily rely on micromanagement of frontlines.

The AI will make use of flexible and balanced cohesion settings depending on the ratio of divisions:frontline length, but will avoid the use of rigid cohesion.

It is worth noting that units that are not placed directly on the frontline (having been left behind or recently added to an order instance) will not be subject to the same cohesion restrictions, and will make use of strategic relocation to find themselves a new place on the frontline. Additionally, the cohesion setting will be respected regardless of whether an order is being executed or not.

Modding

For those of you interested in modding, the addition of these subsystems also comes with some new tools regarding units. It is now possible to iterate over unit arrays in states and countries by condition, and apply a series of effects, including the awarding of medals, history entries, and other basic parameters such as affecting org, strength, and more. For performance reasons, units do not currently support storing or being stored as variables, though we will monitor the need for, and performance implications of doing this in future (I SEE YOU EaW).

Predefined divisions can be set up with lists of historical commanders that they will draw from when their current commander if replaced, should you wish to opt for extreme historical fidelity.

The visual display ranks of divisional commanders correspond to their gained experience, and are fully customizable, though confer no gameplay effect.

Medals themselves can be added to the medal array based on arbitrary conditions, and support a variety of modifiers, not all of which are represented in our vanilla use-cases.

Name combinations can also be split from various random lists, if you have a particular penchant for randomly generated names.

That’s all for now, tune in next week for a second look at how peace conferences are progressing!

Aug 3, 2022

Developer Diary | Plane Designer

Hearts of Iron IV - PDX Katten

Hello, and welcome back to another Dev Diary for the upcoming By Blood Alone DLC and accompanying Patch 1.12! The team has returned from the summer vacation, and we are now back fixing bugs and tweaking the balancing of the new features and focus trees.

Today, we are taking a look at the Plane Designer. As always, any number value that you are going to see in this DD is subject to change.

The Plane Designer became a subject of discussion, both inside the team and in the community, almost as soon as we announced that No Step Back would feature a Tank Designer. We felt that it would mesh well with the rework of the Italian focus tree, not least because the Italian aviation industry was very well developed and produced some of the best combat airplanes of the war - hampered mostly, as Italy so often was, by lacking production capacity.

We also felt that a Plane Designer would help plug some gaps in the lineup of available aircraft. Over the years, many players have commented on the fact that many nations modified their fighters to also be able to carry bombs, or their tactical bombers to also carry torpedoes. One of the big goals of the Plane Designer was to allow for these types of multi-role aircraft.

At the same time, we didn’t want to make these multi-role planes too powerful. Instead, a plane design optimized for a single mission should still be more effective than a multi-role plane. Where multi-role planes offer flexibility, optimized designs offer top performance, if you can afford them.

The basics of the Plane Designer are probably not a surprise for anyone who is familiar with the Ship or Tank Designers. The base is called an airframe, which roughly corresponds to the hulls and the chassis of the ship and tank designers. The Airframes have a number of module slots, where you can put the modules that give the final design its actual stats. There are three different size classes of airframes: Small, Medium, and Large. Small planes also come in a carrier-capable variant of the airframe.

The types of module slots in the Plane Designer are slightly different from the Tank Designer. There are effectively only three types of slots: Engines, Weapons, and Special modules.

Engine modules are perhaps the most straightforward of them. Unlike tanks, where this slot dictates what type of engine the tank uses and a separate stat determines what its speed is, engine modules in the plane designer determine the number and power of the engines mounted on the aircraft. These engine modules produce a new stat called Thrust, while all other modules have another new stat called Weight. These two stats are effectively the limiting factor of what and how many modules you can put on the plane. A design is only legal if Weight does not exceed Thrust (some people might point out that the only planes with a Thrust/Weight ratio of 1 or better in reality are modern, high-performance fighter jets, but these people will be summarily ignored).

Any excess Thrust is converted into extra speed, which is intended to provide a reason not to fill every module slot.

One thing to note here is that jet engines (and rocket engines, for that matter) are part of these engine slots, which means that they are available for all types of planes. This, by necessity, means that Jet Fighters and other jet-powered airplanes are no longer their own unit type - they are now simply fighters with jet engines. Jet fighters will therefore reinforce regular fighter wings, and also that you can now effectively make jet carrier planes, jet CAS, jet heavy fighters etc.with the plane designer.

Or Rocket Naval Bombers, one supposes, if you really hate your pilots on a personal level.

Weapon modules are also fairly self-explanatory. But beyond providing offensive stats like Air Attack, weapon modules fulfill two other major functions. The first is that the weapons define what type of plane a design ends up being. For this the designer has a Primary Weapon Slot. The module in this slot defines the role of the final design, i.e. Fighter, CAS, Naval Bomber etc.

This is relevant because the weapon modules also unlock what missions a design has available. That means that the strict separation of mission by type of aircraft will be gone. You can now create fighters that can provide ground support, or Strategic Bombers that can do naval strikes, depending on the modules you put on the plane. There are, of course, some restrictions - strat bombers can never mount the modules necessary to unlock air superiority missions, for example.

We still wanted to give you an easy way to classify your designs on a high level and it also makes it a lot easier to tell the AI what a design actually is and how it should be used. Without accounting for doctrines, there are no stat differences between, say, a fighter that has a set of 4 Heavy MGs in the Primary Weapon Slot and bombs in a secondary weapon slot, and a CAS that has the bombs in the primary weapon slot and the MGs in the secondary slot - but one goes into Fighter Airwings and the other goes into CAS Airwings.

CAS planes have a large variety of weapons available to them to attack ground targets.

There is a full list of weapons, the missions they unlock, and what they classify a plane as if mounted in the primary weapon slot, below (stats omitted because balancing is still ongoing):

While some of these weapons are unlocked in the (reworked) Air Tech Tree, some of them are also found outside of it, in a similar manner as the tank weapons are found in various trees. I will note that the total number of techs in the Air tech tree has actually decreased.

A view of the Air Tech tree. It has a total of 28 techs, compared to the old tree’s 38 techs.

One notable aspect is that a lot of these modules provide different stats only for specific missions. For true multi-role planes to make sense, we wanted to make sure that building a design with a mixed set of missions didn’t make the plane useless in some of them. Hanging bombs off a plane should make it less agile and slower, but a fighter that was able to do CAS missions shouldn’t be useless in air superiority missions. Thus, the weight and agility penalties only apply to the fighter if it is actually on a CAS mission, not if it is on an air superiority mission.

Modifiers only apply to certain missions. Here, the bombs the Stuka carries make it less agile, but the dive brakes give it better air defense

Finally, we have the so-called “Special” module slots. These are effectively a catch-all term of various different items, a list of which you can find below:

Armor Plate: Increased Air Defense, reduced range
Self-Sealing Fuel Tanks: increased Air Defense, costs Rubber
Drop Tanks: increased range (small airframes only)
Extra Fuel Tanks: increased range, reduced air defense
Dive Brakes: increased air defense, increased naval strike hit chance
Radio Navigation I: reduced night penalty, increased strat attack
Radio Navigation II: reduced night penalty, increased strat attack
Air/Ground Radar: reduced night penalty, increased strat attack, increased naval detection
Air/Ground Radar II: reduced night penalty, increased strat attack, increased naval detection
Air/Air Radar: reduced night penalty when on intercept mission
Air/Air Radar II: reduced night penalty when on intercept mission
Floatplane: increased naval spotting (small airframes only)
Flying Boat: increased naval spotting (medium+large airframes)
LMG Defensive Turret: increased Air attack, reduced agility
2x LMG Defensive Turret: increased Air attack, reduced agility
HMG Defense Turret: increased Air attack, reduced agility
2x HMG Defense Turret: increased Air attack, reduced agility
Cannon Defense Turret: increased Air attack, reduced agility
2x Cannon Defense Turret: increased Air attack, reduced agility
Recon Camera: unlocks recon mission (LaR only)
Demining Coil: unlocks demining mission (MtG only)
Bomb sights I: increased strat attack
Bomb Sights II: increased strat attack
Non-Strategic Materials: reduced Aluminum cost, reduced air defense

Special Modules are primarily intended to help optimize planes for various missions or give them different niches.

The eagle-eyed amongst you have already spotted that planes now have a surface and sub detection stat. Up until now, planes that were active in a sea zone always provided a flat bonus to the spotting speed of any navies active in the seazone. This will now change, with planes having dedicated spotting stats that determine how well they do with helping the navies spot. There are modules, like the Air-Ground Radar and the Flying Boat hull, which give bonuses to naval spotting.

Vanilla planes have those stats already baked in, with some being better than others - carrier planes are better than their land-based counterparts, naval bombers are better than fighters etc.

To further support this, we are adding two more things: Maritime Patrol Planes as a dedicated unit type and a special Naval Patrol mission for planes with the right modules.

Maritime Patrol Planes are built on the Large Airframe, giving them exceptional range. They are able to mount the whole array of naval bomber weapons, but naval strike is really not intended to be their primary role. Maritime Patrol Planes are meant to help with spotting raiders in the deep ocean, where smaller planes with shorter ranges struggle to provide much mission efficiency.

You can run naval patrol missions with many different types of planes.

Finally, let’s talk a bit about art! While we already have a large amount of historical art for various plane types, we also wanted to give you more options to visually distinguish your designs, even if it is just to find the plane design more easily in the production menu. For the tank designer, we split up the existing art and recombined it into various combinations to quickly generate a large number of assets. We realized early on that this wouldn’t work for the plane designer. So instead, we decided to fill in some gaps in the existing art as well as add some art for a number of prototypes that flew but were historically passed over for mass-production.

Here is a partial list of new plane icons coming in BBA. Which one’s your favorite?

We also decided that we wanted to add more 3d art. Much like the tank designer, you can select these assets when you design the plane. We are adding about 80 new 3d models for planes to the DLC, but more on that in the future!

Here is just a teaser of some of the new assets coming in the DLC:

That is about it for this week. We hope that you will enjoy playing with the Plane Designer as much as we enjoyed making it. To end this DevDiary on a personal note: The Plane Designer will be my final contribution to Hearts of Iron 4. After close to 6 years on the project, all the way from the early days on Together for Victory, the time has come for me to leave the company and move on to greener pastures. It has certainly been an eventful and productive couple of years, and there are many things that I am very proud of (and a few that I regret - like adding Austria-Hungary as a joke and then finding out that people love monarchism). Working on the Hearts of Iron series has always been a dream for me, since the day I launched Hearts of Iron 1, almost 20 years ago now. Few people can say that they had an impact on a piece of entertainment that has had a similar impact on themselves. But the thing I am most proud of is the team we have built. Hearts of Iron is in very good hands, and there are years of content still to be released. I’m looking forward to it - but, once again, as a player.

Weird designs that QA came up with:

This single plane outguns an entire tank platoon, unfortunately it can’t ever turn:

And then we restricted the number of bomb bays you can have on a plane:

6 engines, 8 cannons, 4 cannons in turrets, and a production cost 50% higher than a strategic bomber. Needless to say, this combo is no longer possible:

When you look at the Spitfire Mark I’s armament and wonder: but what if…more guns?