Basics of technology
Your technological progress in the game depends on your technology investments reaching the cost of researching the next level. Once the investment reaches that amount, the technology level is adquired.
The technology cost depends mainly on the base value of the technological level being researched. This is a fixed value for each level of each technology, that is increased by the following factors;
- Your country size (number of provinces fully settled). Tech costs increase greatly (in the range of 10% to 20%) with every province that you have over your capital until you have eight provinces. Once you have eight provinces technology costs continue to increase slightly (a little more than 1%) with each additional province until the cap is reached at 68 to 90 provinces depending on religion. Pagans which are already penalized for tech costs cap at 68 provinces while Reformed countries which have the least penalty cap at 90 provinces. This is the reason why single province countries on a rich province and big countries advance faster than medium size countries.
- Your religion. The cost of research is slightly decreased for Protestant/Reformed over the base cost for Catholicism. All others cost is slightly increased except for Hinduism and Confucianism, where the cost is significantly increased, and Paganism where the cost increases a lot.
- Your technology group. This has nothing to do with religion, but with the geographical region the country is located. It tries to reflect the fact that science and technology were developed in Western Europe. The more remote you are, the more expensive research is for you. See below for the areas and their exceptions.
- As everything else in the game, your level of inflation.
The technology cost is modified by the position of your Centralization and Innovativeness DP sliders. It can go from -35% (fully centralized, innovative) to +35% (fully decentralized, narrowminded). The technology cost can be increased by several penalties that apply to certain countries:
- The ahead of time penalty. Technology cost for research, can be increased by a penalty known as "ahead of time penalty (ATP)". Basically, each level of research has a standard date for being researching it. If you are researching it 5 years before this date its cost is increased by several times (around 2.5 for some versions). Every year before 5 increases this penalty slightly. You know you are suffering from ATP if the cost for the technology gets reduced the first of January.
- The isolation factor penalty applies to any country that does not know at least 19 other countries (check your relationship list in your diplomatic info screen if in doubt). No european country suffers from it. If you are an isolated country, you have to do your best to get maps that will allow you to know more countries. When a member of an alliance declares war to an isolated country, and the rest joins, their capitals become known. If you find a colonizer that is alliance leader, bribe him and join the alliance. Honor the war and jump alliances. When isolated nations annex their neighbors, their penalty increases as the number of known countries reduces. The isolation penalty is about 5% additional tech cost for each country less than 19 known.
- The whiteman penalty is several times worse than the isolation factor and applies to all native american pagan nations for being in an unknown continent. The way to eliminate this penalty is to have five interactions with non-american nations, wether diplomatic, commercial (sending merchants to european CoTs counts), or more often having five wars. Check your technology cost in the budget allocation slides. When the technology cost drops drastically after an interaction, the whiteman penalty has been released. If you have a whiteman penalty you are not allowed to build cavalry or ships whatever your tech level (you did not know about them).
The technology investment is the amount of resources that go into research, and is not related to the cost. It is determined by three factors. The first is your monthly budget allocation. If you don't invest in stability or treasury, your full monthly income minus the army and navy maintenance cost will be invested in technology. The second is your monarch skill. Administrative skill invests into trade and infraestructure research. Military skill invests into land and naval research. The third is your neighbor bonus. Its value is determined by the difference of technology level between the most advanced country in your tech group and you (the same applies to the AI countries), and this bonus is also reduced by the tech group if different than Latin (see below). Also some events, both random and historic, will give or take a lump of money from the amount already invested. Do not press the button left of the slider. It will deduct 200d from your treasury and invest 100d in the particular technology. There are always better ways of investing your valuable treasury.
The technology groups are:
Latin: All european catholic, and protestant/reformed countries and Granada. No increased cost for technology. They get the full amount of the neighbor bonus.
Orthodox: All european orthodox countries. Poland and the Ottoman Empire might belong to this group or to Latin and muslim respectively depending on historic events. Technology is 10% more expensive. They get 80% of the neighbor bonus.
Muslim: Sunni and Shiite countries plus China, Shonghay, Zimbabwe, Zanj, and other Africans and Asians. Technology is 20% more expensive. They get 60% of the neighbor bonus.
Chinese: All non-muslim asian countries except China that might belong to this group by event. Technology is 40% more expensive. They get 30% of the neighbor bonus.
Exotic: All pagans plus Nubia, Khazaks, Uzbeks, Chagatai, Ak & Kara Qyunlu. Technology is 90% more expensive. They get 10% of the neighbor bonus.
Technology costs and neighbor bonus are one of the aspects of the game that get changed nearly all the time. Take the values given as orientative. You get the picture.
This complicated system is designed to reflect historical technological advancement through the period. It is also compensated so small, poor countries develop almost as fast as big ones and tries to prevent the human player from hyperteching in military and crush every other country. You will technologically advance at a similar pace as your neighbors provided you invest a reasonable amount into research, something important since the AI is much worse than the human player in technology investment. Some recomendations follow this analysis. As everybody will tell you, you should invest heavily in Trade and Infrastructure, because the first three levels have no ATP and because they will improve your economy, feeding back into all research. Also the dates for ATP in trade and infra are set later, so you can get a bigger advantage over the AI. Although you will lag a little bit on military until your economy flourishes, this is hardly crucial, because the neighbor bonus should prevent you from stalling. But don't forget Land levels 5-9, they are researched fast and are a very significant difference in terms of battle results.
If you like to go into numbers, look into the technology cost in December and January and write them down. If they are the same you don't have ATP for that technology, and that value is the base cost for that level of that technology for you. If the cost got reduced by about half (reductions between 35-75% depending version and patch), you just hit the threshold year for the ATP on that technology. The January figure is your base cost. If the reduction is a small percentage, multiplying the reduction by ten will give you the base cost. You are paying an ATP for that technology. If you are investing a lot more than your base cost, consider shifting your investment to a technology where you don't have ATP to maximize return. But remember that if you gain a level in infra or trade ahead of date, the benefits for those years will cover part of the extra expense. If you have to invest against ATP do it in trade or infra.
Regarding the tech group penalty and other penalties, if you decide to play a pagan american (worst case) your technology cost can be in the order of ten times higher than for europeans. No matter how you look at it you are going to be very backwards. By removing the whiteman penalty and the isolation penalty and converting (religion is a small factor compared to the tech group), the technology penalty will still make research twice more expensive, and you will never get any significant neighbor bonus. The europeans are not your technology neighbors, even if you have a land border with them.
For exact values/effects visit the Tech tables page