There are four different technology field you advance through, where each level gives you a higher bonus in that category. The research of technology is automatic, and depends primarily on your citizens. Inventions and access to certain trade-goods will increase the speed with which you research, while the total amount of pops you have determines the cost.
Each technology-field can have one researcher assigned to it. The finesse of this character impacts the speed with which research is done in that field. This character gets prominence from holding the position, and gets permanent prominence from each month holding the position. Changing researcher increases loyalty in the new researcher, and dramatically drops it in the one being replaced.
Research a level takes about 15 years if you are at 100% efficiency, which can obviously be faster or slower, depending on the setup of your nation.
Each level researched in the four technology fields reduces invention costs by 5%, and they have the following individual bonuses.
+10% Naval Morale, +10% Land Morale, -25% Military Tradition Cost
+2% Commerce Income
+2% Omen Power
While the advances are tied directly to your nation’s progress, and is a slow progress through the years, there is also inventions around, that you can spend civic power on to get immediately.
There is always seven inventions to pick from, from a total of over 200 different ones. Each of them have a tech-level they are most likely to appear at, so you can’t stack or get all discipline bonuses in the first decades of the game no matter how lucky you get.
Each invention costs you 50 civic power, but for each invention you have taken, the cost goes up by 20%, while as we mentioned earlier technology advances reduce it by 5% each.
Military Level 1:
Professional Soldiers: Trireme Discipline +2.00%
Learning on the Job: Starting Experience +5.00%
Military Artisans: Military Tech Investment +5.00%
Military Level 2:
Supernumerarii: Supply Limit +10.00%
Extraordinary Ordinance: Siege Ability +5.00%
Fustuarium: Heavy Infantry Discipline +10.00%
Military Level 3:
Sapping: Siege Engineers +1.00
Pentaspastos: Fort Defense +5.00%
Material Science: Military Tradition Cost -10.00%