Darkest Hour - Dev Diary #17 - Tech Tree Part 1

  • We have updated our Community Code of Conduct. Please read through the new rules for the forum that are an integral part of Paradox Interactive’s User Agreement.


Field Marshal
86 Badges
Feb 24, 2009
  • Victoria 2: A House Divided
  • Sengoku
  • Semper Fi
  • Victoria: Revolutions
  • Europa Universalis IV: Res Publica
  • Magicka
  • Leviathan: Warships
  • Knights of Pen and Paper +1 Edition
  • Victoria 2: Heart of Darkness
  • War of the Roses
  • Hearts of Iron IV Sign-up
  • Europa Universalis III Complete
  • The Showdown Effect
  • Warlock 2: The Exiled
  • Crusader Kings II: Conclave
  • 500k Club
  • Stellaris
  • Europa Universalis IV: El Dorado
  • Imperator: Rome Deluxe Edition
  • Crusader Kings II: Way of Life
  • Pillars of Eternity
  • Imperator: Rome
  • Europa Universalis IV: Common Sense
  • Stellaris: Ancient Relics
  • Knights of Pen and Paper 2
  • Europa Universalis IV: Cossacks
  • Hearts of Iron IV: Cadet
  • Surviving Mars
  • Stellaris: Synthetic Dawn
  • Cities: Skylines - Green Cities
  • Europa Universalis IV: Cradle of Civilization
  • Hearts of Iron IV: Expansion Pass
  • Stellaris: Apocalypse
  • Europa Universalis IV: Rule Britannia
  • Cities: Skylines - Parklife
  • Europa Universalis IV: Dharma
  • Stellaris Sign-up
  • Stellaris: Megacorp
  • Hearts of Iron IV: Death or Dishonor
  • Europa Universalis IV: Golden Century
  • Crusader Kings II: Reapers Due
  • Europa Universalis IV
  • Europa Universalis IV: Rights of Man
  • Tyranny: Archon Edition
  • Stellaris: Digital Anniversary Edition
  • Stellaris: Leviathans Story Pack
  • Crusader Kings II: Monks and Mystics
  • Stellaris - Path to Destruction bundle
  • Europa Universalis IV: Mandate of Heaven
  • Crusader Kings II: Holy Fury

Today and next week we're going to introduce you to our new tech tree, with a good analysis that I'm sure will help you on your first games. :)
Be aware that not everything is finalized now so there may be a few changes on the released product.

Let's start from the infantry tech tree.

As you can see Infantry, Light Infantry and Cavalry start with a 1870 model. This has two reasons:
  1. to represent countries that do not have up-to-date technologies at the beginning of WWI;
  2. to be able to easily expand the timeline;
You'll see on the other tech trees that many techs have a date before 1914. We hope the modders out there will appreciate it. :D

Light infantry represents earlier models of mountain infantry: they move slightly faster than regular infantry, consume less supplies and are superior in harsh terrain, so they are ideal for colonial warfare, but they also have low toughness and soft/hard attack. Marines are introduced in 1922 whereas Airborne Infantry in 1938. The first Motorized Infantry tech is introduced in 1935, as historically the first motorized division were created around this time. Mechanized infantry has to wait until 1942.
The first Engineer Brigade is introduced in 1911 and better models will also give other bonuses (to TC and airbase construction for example).
Finally the techs of the Supply/Logistics/Repair branch go from 1910 (Army Logistics) to 1955 (Modern Repair). This branch has been reworked and gives many different bonuses.

Armor and Artillery

Artillery is obviously one of those techs with many models that goes from 1911 (Light Field Artillery) to 1955 (Advanced Field Artillery), for a total of 14 models. Both Self-Propelled Artillery and Tank Destroyers are introduced in 1940.
And now, something a bit different from the usual. The Anti-Tank Artillery branch will not create a new brigade, but instead it will give bonuses to the hard-attack of the Artillery Brigade! So if you want your Artillery Brigade to be effective against armored units you should research this branch. Moreover, thanks to our engine changes, the hard-attack bonus is immediate and there's no need for events to make it happen. We hope you will appreciate it. :)
Something similar happens with the Rocket and Self-Propelled Rocket branches. Researching normal rockets will give a bonus to the soft-attack of the Artillery Brigade, whereas Self-Propelled Rockets will give bonuses to the soft-attack of both Self-Propelled Artillery and Tank Destroyers brigades.
The Armoured Cars technologies span from 1911 (Prewar Armoured Car) to 1954 (Modern Armored Car), with 8 different models.
As you can see there are three different branches for the Anti-Air technologies:
  • Static Anti-Air, which gives bonuses to the anti-aircraft guns that can built in every province and to AA naval brigades;
  • the usual Anti-Air Artillery brigade, which is introduced in 1918, near the end of WWI;
  • the new Self-Propelled Anti-Air Artillery brigade, which is introduced in 1940;
And now, let's talk about tanks! There are a couple of other tech tabs involved, but it's better to give you the complete picture here:
  • first of all, the first Experimental Tank technology is placed in the Secret Weapons tab and its purpose is only to enable the research of the Super heavy WW1 Tank tech (on the Secret Weapons tab too): this tech will allow the building of the first model of the Super Heavy Tank brigade;
  • after researching the first two techs from the Secret Weapons tab, on the Armour Tab you can research the Mid-Great War Tank 1917 tech, which disables the Super Heavy Tank Brigades and allows the building of the Heavy Tank brigade;
  • after that, the Late-Great War Tank 1918 technologies activates the Light Tank Brigade (this change of brigade types can be confusing but we thinks it's a good and historical depiction of the birth of tanks as weapons);
  • the Post WW1 Tank techs will disable the Heavy Tank brigade and create new models of the Light Tank Brigade;
  • now we should take a look at the Land Doctrines tab: there you will find a tech called “Armored Division formations”. This doctrines represent the idea of creating Tank Division instead of Tank Brigades and is necessary for the creation of Light Armor and Medium Tank Divisions;
  • after researching the Armored Division formations doctrine, in the Armor Tab from 1936 onwards you can research the Light Tank Divisions and then from 1939 the Medium Tank Divisions (which after WWII will evolve in the Main Battle Tank branch);
  • from 1939 onwards it will also be possible to research a new Heavy Tank Brigade (5 models, up to 1955);
  • in 1944 there is also a tech to create a new Super Heavy Tank Brigade (to represent the Tiger II for example), but there will be only this model;


The Agriculture, Manifacturing and Construction Engineering branches have been expanded to cover the entire timeline (approximately 1910-1964). The Agricultural techs now give bonus to IC and production of supplies rather than manpower. The Construction Engineering techs gives bonuses also to the construction of Nuclear Reactors and Rocket Test Facilities.
The Census Tabulating Machine tech now is introduced in 1897 and this branch also activates and upgrades the Fire Control Naval Brigade. The Encryption/Decryption branch is also extended to cover the DH timeline.
The Radar branch starts with the 1936 tech Basic Decimetric Radar Warning Sites which enables the new Air Scramble mission. Later techs of this branch activate the Radar Naval Brigades (and enable the research of a new secret tech!).
The new Medicine branch, which starts in 1910, increases the quantity of available manpower (relative manpower).
Finally, the new Specialised Equipment branch gives bonuses to the land units in frozen, tropical, desert or rough terrain.
This is not yet set in stone, but there will probably be decisions linked to these techs. For example researching winter equipment for both infantry and vehicles will enable the “Production of Winter Equipment” decision that will give even better bonuses to your troops (given enough time). Beware that it will be an expensive decision that should not be taken lightly!

Land Doctrines

First of all, there is a new branch of land doctrines dedicated to the Great War. There are two different path, the Leading by Orders Path and Leading by Task Path. Both of them start before WWI (in 1907) and lead to different post-WWI tech (in 1923), with the Specialized-branch tactical experience and Cross-branch tactical experience techs.
Moreover, the 1926 Post Great War Unified Doctrines is a tech alternative to the whole WWI branch. Basically a minor country can choose to follow the whole WWI path and research all those doctrines or research only the Post Great War Unified Doctrines tech which gives almost the same bonuses (researching the whole WWI branch gives better bonuses, but is obviously more expensive).

Now let's take a look at the WW2 and post WW2 path. As you can see there are 5 different paths:
  • Firepower Focus / Superior Firepower Path (US)
  • Defensive Focus / Grand Battleplan Path (UK, FRA)
  • Mobility Focus / Blitzkrieg Path (GER)
  • Manpower Focus / Human Wave Path (SOV)
  • Light Infantry Focus / Minor Countries Path
The Grand Battleplan Path after World War II is united with the Superior Firepower Path (with the Modern Branch Interoperability tech). The Light Infantry Path post WWII gives access to only some of the common techs of the other 3 main paths (Night Vision Tactis, Aircavalry Doctrine, Special Forces Focus Doctrine).

The Armor Division Formation (necessary to activate the Light and Medium Tank Division, as explained before) can be activated by different land doctrine techs from different branches. For example in the Superior Firepower Path, it's the 1940 tech Integrated Support Doctrine that enables the research of the Armor Division Formation, whereas in the Blitzkrieg Path it's the 1937 tech Spearhead Doctrine that enables it. ;)

And to close this Dev Diary, let's take a look at the extended tooltip: very useful to discover required and unlocked technologies! :)

Come back next week for the second part of the tech tree!
Last edited by a moderator:
Two thoughts (well 3 really): first of all great read, I really like what I see :). Some great ideas as well. I`m wondering about the way anti-tank artillery is gonna be represented in the game though. I`m affraid not having AT brigades will mean people will just use 1 and 1 only types of brig - Artillery, especialy that AT branch makes it even better.

Last thing: in the tooltip, is it possible to have the time of finishing the research mentioned? Some people use Research Assistant, that would be a way of implementing one into the game. And, from my point of view, really useful tool for picking up the right tech team for the research.
why not add, a tech that will determine the philosophy of your industrial-military production?
Aircraft, Tanks and Navies etc will have 3 tipes of "sliders" :Engine, Armour and Weapons. Each of these will have 3 options:

Fast ( -for TANKS:higher speed, lower hard defence and reliability, and a little higher cost and fuel consumtion- -for SHIPS:higher speed higher cost and time and fuel consumption- -for AIRCRAFT: higher speed, higher air attack and deffence also higher land deffence at a cost of much bigger cost and construiction time and fuel consumption and maybe range-)
Balanced (no change)
Strong ( -for TANKS: lower speed, higher defence, reliability and bonus in difficult terrain and higher cost- -For SHIPS: higher sea and air deffence along with cost and fuel consumtion and lower speed)

Strong (all 3 tipes will have higher deffence, lower speed and higher fuel consumption along with higher cost)
Light (all tipes will get lower deffence, higher speed, lower fuel consumption, wit a little lower cost)

Strong( higher attack, higher time cost and supply consumption)
Light (lower attack lower cost and time and supply consumption)

Along with theese you could also add a simmilar tipe to the stile of construiction:
Quality(higher time and cost with a bonus to organisation)
Quantity (lower time and cost along with lower morale and organisation)

The AI will choose a certain historical path (maybe changing it if certain evvents happen like germany switching from light-fast tanks to heavy ones) and the player, after he chooses to research these paths will not be able to abandon them untill the yearly event that asks if he wants such modiications for each tech, but at a heavy cost to IC
Last edited:
I like your handling of rocket artillery, as it will both help the AI and reduce the micromanagement. However, I'm not so happy with the AT techs. As mentioned by Sathariel, it may easily upset the balance, especially given the fact that Artillery brigade was already very strong. In case of rocket artillery it's quite logical, because it's still just artillery, just costlier, improved one. AT guns are a different matter, though. If Artillery will be good against everything, then it will make other brigades pointless. I would advise you to change it.

I like the new doctrine and industry trees. There seem to be enough choices to satisfy the demand and the visualisation is very good ;) It's good that you are making the doctrines more important.
And will you make engineers more powerfull? Maybe affecting 3 division instead of the one bearing it.
Not only engineers should be more powerful. Tank destroyers, heavy tanks, anti-aircraft, armoured cars and other brigades need to be useful. There is a reason why they were used IRL and it should be represented in-game. I hate how often in HOI games building just one brigade type (usually ART) or no brigades (HOI2 Vanilla) is often the best way to go... No major army in the world relies on one weapon type alone.
I like the AT change very much since I equip my whole army with Art or SpArt anyways... This is also a very nice way to implement the short lived Assault Gun which was neither a tank destroyer nor a self propelled artillery.
Both the particular effects of engineer brigades and the "Hammer of Gods" doctrine remain of high interest for me xD

Not only engineers should be more powerful. Tank destroyers, heavy tanks, anti-aircraft, armoured cars and other brigades need to be useful. There is a reason why they were used IRL and it should be represented in-game. I hate how often in HOI games building just one brigade type (usually ART) or no brigades (HOI2 Vanilla) is often the best way to go... No major army in the world relies on one weapon type alone.

But many weapon systems are too small to fit the scope. When was an independent brigade of armored cars used in the war?
Very interesting how you merged the indirect fire brigades! But what happend to the sp artillery?
SP Artillery is still there, look under Artillery. As mentioned above, SP Rocket increase the soft attack of SP Artillery.

I don't have the answer to the other questions, sorry.
But many weapon systems are too small to fit the scope. When was an independent brigade of armored cars used in the war?
Weapons that "don't fit the scope" should be represented as bonuses to "base" units IMO. However, that's not the point. If there are e.g. 6 or 7 brigades in the game, then ALL of them need to be useful (that doesn't mean that they have to be the same - quite the opposite!) and balanced. Otherwise, there is no point in adding them in the first place.

Lack of AT brigades is bad even from gameplay perspective. If everyone will build just ART and AT techs will make ART potent against armoured formations, then all units with ART (most of the army) will be good against ARM. Force distribution will be unimportant that way.
The tech tree looks really good, but the land doctrine part worries me a little bit. I hoped for a more generic approach where I can actually shift my focus, depending on the course of the war. An example Germany might want to prefer concentrate on nuclear research instead of the rocked techs. It will however never be able to research the Nuclear focus doctrine. Speculating about a possible naval tree Germany could never become a (surface) naval power, while the US could never really rely on submarines.
Playing Iron Cross at the moment this kind of tech tree is combined with a great imbalance in the different sections. So my request is to balance the tech tree in a manner that after a certain iteration (e.g. half doctrine tech tree an full doctrine tech tree) all major players/doctrine paths are balanced, so that on average nobody has an advantage.
I like the technology tree and improved tooltip. There are few concern:

1. It was stated a lot that the game is mostly about WW1 and WW2. Considering this, I believe there are disproportionally lots of interwar and postWW2 technologies while to few WW1 and WW2 technologies. For example, there are 3 infantry technologies for WW2 period and 5 infantry technologies for post WW2. Splitting 1942 technology into 1941 and 1943 technologies, and to compencate removing one technology for post WW2 would make much equal ratio of 4 and 4.

2, Once the country is on one doctrine path, it's impossible to change doctrine if the situation changes. That is not very historical.
All looks clear, but have to say that IC tech tree capture my mind. For long period simulation this classic tech tree is ok choise, even I dislike a lot "year bind" techs. Hope to see "colorfull" choises and player are allowed make (even stupid) choises. And don't let player get everything.

Choises (and not to choose) make game intersting. Please let player to choose way. To go with history, to make some changes or to proceed totally something else - like let axis proceed to carriers if they like really want.

Currently in IC game, I was able to attack France with brand new mark IV at fall 39 and rush to Russia in 40 spring with high mobile army. This was done by high cost of other techs like Air and Sea unist. And try now build nuke & missile ASAP. Imbalance - maybe but I made my choises, they give serious troubles when get advance on other way. What is THE balance anyway :)

But hope to see day soon when DH is ready to purchase.
2, Once the country is on one doctrine path, it's impossible to change doctrine if the situation changes. That is not very historical.
I am not sure, but I think that if you want to change doctrine you have to abandon all the techs of your current path and start researching the new path. It is possible, but expensive.