Crusader Kings II Wiki
Tech 2
The technology system changed quite a bit with the release of The Old Gods. Read more on the paradox forums in the developer diary about the new system.

Much like construction, technology is a long-time prospect. Unlike construction however making progress in technology takes decades, and the effects are tiny in comparison. I'll go into how technology works, and what you can do to maximize your benefit from it.

If you can't be bothered to read all of this, there's a summary at the end.

What It Does

The basics of how technology works in Crusader Kings II is rather simple, but not immediately obvious. Technology works on a per county basis; technology in one county will not directly benefit any other counties.

For every whole level of a technology, you'll get a benefit in that county. There are a variety of effects, and these will be gone into in a later section.

How It Spreads

Technological progress happens based on percentage chances. Every month you have a percentage chance of making progress for each tech for each county, measured on a per year basis. Through a dice roll you either make progress towards the next level, or remain where you were before.
Each time the dice roll succeeds, your technological level for that specific tech in that specific county increases by 0.1.

Once the technological level reaches a whole number, you gain the benefit from that level; you don't get say 50% of the effect of level 2 if you're at 1.5, you get the effect of level 1.

Most of your tech will be achieved through the dice rolls mentioned earlier. The percentage chances in a county are affected by several conditions:

  • What year it is
  • State attributes
  • Tech focus
  • Councillor missions
  • County buildings
  • Other counties

All of these factors are multiplied together to decide the final percentage. The base percentage is always 1.2% per year, but this can be increased to much higher levels.

The Effects

There are in total 18 different technologies, 6 for each major area: Military, Economy, and Culture. The effects are as follows:


  • Light Infantry - Light Infantry and Archers receive a better attack and defense at an increase of 7.5% per level.
  • Heavy Infantry - Heavy Infantry and pikemen receive a better attack and defense at an increase of 7.5% per level.
  • Cavalry - Mobile units (Horse, Camel, Elephant) receive better attacks and defense at an increase of 7.5% per level
  • Siege Equipment - Siege attack and defense increase by 12.5% per level
  • Shipbuilding - Allows for the construction of Ships, the first level is granted automatically to the Norse at certain early years. Size of fleet is increased 10% per level. Building upgrades end at level 4.
  • Military Organization - Increase the moral of units by 6.25%(rounded down), Global Supply (attrition) by 12.5%, and increase retinue size by 150% per level.


  • Castle Infrastructure - Upgrades your military buildings, Castle Town size, and provides Castle Tax increase of 6.2% per level.
  • Town Infrastructure - Unlocks town buildings, and provides Town Tax increase of 6.2% per level.
  • Church Infrastructure - Unlocks church buildings, and provides Church Tax increase of 6.2% per level.
  • Improved Keeps - Upgrades City Walls, Fortifications, and Keeps.
  • Trade Practices - Upgrades Ports, ability to found a Merchant Republic, Increases Trade Value 7.5% per level and changes Trade Post Limit from -66% at level 1 which increases by 10% after level 3 to a max of 50%
  • Construction - Reduces construction time and cost by 3.1% per level to a max of 25%


  • Noble Customs - Increases opinion of nobles by 3 per level
  • Popular Customs - Increases opinion of burghers by 3 per level
  • Religious Customs - Increases opinion of priests by 3 per level
  • Majesty - Increases prestige and piety by 6.25%(rounded down) each level, Reduces Short Reign by 1 every 2 levels.
  • Tolerance - Opinion penalty is reduced 6.25%(rounded down) each level for both Culture and Religion
  • Legalism - Allows for Crown Authority and Centralization changes, Special Decisions at level 4 and 8, and Higher Taxes and Maximum Levies at levels 6 and 7 respectfully.

What To Research

Now, the culture techs are special in that they only affect you if your capital county has the technology. A low or high tech outside your capital will not hurt or help you directly in any way.

The culture techs are also, arguably, by far the most useful techs, especially the customs techs and legalism. Both let you manage a large realm easier, and makes succession better. The Tolerance is also useful if you expand into areas with different culture or religion than your own, and thus end up with foreign vassals.

So for the culture techs, I would recommend focusing on Legalism even if you're not a King/Emperor as it will allow you to control more land directly through Centralization Law. When you do become King/Emperor you are then allowed to change Crown Authority to increase your Vassal Levy Size. Second I would focus on Noble Customs as that will affect pretty much everyone in your realm with any real power. Majesty Laws would come in as a good third to reduce your Short Reign years, but concentrating on Popular or Religious would end up assisting with taxes and levies.

For the economy techs, Castle Infrastructure is most important because it directly increases your income from a holding by 6.2%, plus the +2 Tax Income provided by Castle Towns. Trade Practices next if you're a Merchant Republic. Otherwise Construction and Improved Keeps for the benefit of extra levy size and income from Walls.

For the military techs, Tactics is quite useful as it affects all your units. Military Organization helps in keeping troops in battle through moral. A low moral army will disintegrate faster. Beyond that you should probably just concentrate on whatever unit(s) you get from your culture's unique building.

How To Maximize Technological Growth

First off, don't try to get too far ahead of the curve, as you'll get a large 'ahead penalty' towards technological growth if you do so. Instead, try to just keep a few decades ahead of opposing realms.

Second, try to get as good councilors as you can, and especially your Court Chaplain. Your state learning (your own stat + your councilor's stat + half your spouse's stat) plus the state stat for the relevant area will increase technological growth in that area by as many percent. This can make a huge difference in how fast you achieve technological growth.

Third, use your tech focus to get what you want, and switch once you've achieved that level. It also benefits you to boost techs that are nearing the next level, as this will fuel tech growth in the rest of your demesne.

Fourth, focus on your capital. As the entire culture branch works based on your capital, there is no real point in encouraging cultural tech elsewhere.

Fifth, build the tech buildings in your capital. By upgrading the Monastic School and University in your capital county, you can easily achieve 50% higher technological growth there.

Sixth, use your councilors whenever they're available. Have them boost tech growth in your capital. They'll increase tech growth in that county by 5% per level they have in the relevant skill.

By concentrating entirely on your capital, you'll also be indirectly increasing tech growth in the rest of your realm as well. Neighboring a county with a higher tech level will increase tech growth by 15% per county, and having a county with a higher tech level in the same demesne will also increase tech growth by 25% per county. Thus, when you achieve a higher level in your capital you'll increase tech growth in your entire demesne for that tech by 25%, and by another 15% for any county your capital borders.


By maximizing technology you can get the edge you need to survive against the odds, and to deal with bad successions. Investing early in technology can benefit you for the entire length of a campaign, and can bring large benefits.

For those who cannot be bothered to read everything, just remember this:

  • Concentrate on your capital
  • Focus on Legalism and Noble Customs, Castle Infrastructure and Improved Keeps, Tactics and Military Organization
  • Get as good councilors as possible
  • Use your councilors to boost tech growth in your capital
  • Build tech buildings in your capital
  • Utilize your tech focus

Published by Meneth

Small note from random guy: Moving the capital to a province of Muslim/Greek origin can give you a boost in Legalism and rest of tech by 3. + it gives all other provinces a boost in tech development.