Unlike most other Paradox Entertainment games, Imperator: Rome comes with a pretty complex technology tree. It’s not the amount of content that is there, rather the freedom to pick anything you want, and the fact that you can’t pick everything.
It’s not like EU4 where you simply pick the next tech level when you have enough mana points, nor is it HoI4 where you decided whether to research heavy tanks or subs or aircraft guns. It is close to Victoria 3, but in that game you can and will research everything.
So how do you decide what to research?
Note that this is actually a guide for Invictus mod for Imperator: Rome, which is the only proper way to play the game.
Forget About Naval Tech
Your first lesson is to forget all about naval tech. This is found under military technology tree. The techs here improve your naval units, so why shouldn’t you research them? The answer is simple, in the timespan of Imperator: Rome you can only research a certain number of inventions. And since naval warfare plays almost no role in the game, it doesn’t make any sense to research anything, as the bonuses from other techs are always more important.
If you need to win naval battles, invest in military traditions, or simply build more and more ships. Whatever the case, naval inventions are never worth the investment.
The Big Three: Grand Temple, Grand Theater, and Foundry
There are three building in the game that you need to unlock, and these happen to be the three most important buildings when it comes to building anything at all. And the reasons are rather simple:
- Grand Temple
Grand Temple increases the speed at which pops are converted to your religion. Once converted, they convert faster to your culture too. Most importantly, this means higher happines which means less revolts and more income. Provincial loyalty is also increased.
You can find the Grand Temple building under Open Religion in Religious Advances:
- Grand Theater
Increases the speed at which pops are assimilated, increases integrated pop happiness, and increases provincial loyalty.
Grand Theater can be found under Gradual Economic Integration in Oratory Advances
- Foundry
Increases base resource production, together with slave and freemen output. The economic building of the game.
Foundy can be found under Centralized Production in Martial Advances.
Conversion and Assimilation are the Key
Integrated pops (or primary culture pops) are always the most beneficial for your country. Not only because that is how you raise levies, but because they are happier and when they are happy they don’t revolt (so often anyways) and they produce more. Bigger armies, more money, less headache. And whilst you can integrate other cultures, it is only beneficial in the early game, and when trying to unlock new military traditions.
And since converting and assimilating are so important, it is obvious that the buildings that speed these up will be your first targets for research. This will take the initial eight inventions you have.
Choosing What to Research Next
After these three there are a variety of routes to go. This somewhat depends on what you choose to prioritise. Some considerations include the following:
- Even faster conversion and assimilation
Again, conversion and assimilation are key. There are several techs lie Ban Witchcraft and Formulaic Worship in Religious Advances, or Religious Assimilation and Cultural Administration in Civic Advances that speed up the process in further.
- Military experience for Military Traditions
In my experience, this is what you should prioritise next. Martial Advances offers a handful of techs that increase the starting experience and experience decay. These include Professional Training, Basic Training, Multi-Discipline Training, and others that increase these modifiers. They are also within fairly easy reach.
What makes them so important? The more starting experience your levies have, and the slower it decayse, the more Military Experience you get when you disband levies. And that is what is needed to activate Military Traditions. However, you do need big levies for this, as that is another scaling factor.
- Happiness and Growth
There are a dozen or two dozen techs that increase integrated and unintegrated culture happiness. Some of these are between the major techs, and others are spread out. Usually found in Religious Advances or Civic Advances, but there are a handful in Oratory Advances too. You will also find techs that increase happiness of population types. There are so many that it’s pointless to list them, you’ll simply have to spend time checking out the tech trees.
Growth is something that you will also need, especially once you reach midgame. Religious Advances is what you want to have a look at, because these techs increase food production and population growth. F.U.G, Grain Rations and Bread Stamp will get you started. In Civic Advances you want to research your way into Urban Planning.
- Economy
Once you’ve made your way through the above, and have invention points to spare, I would put them in economy. These boost trade routes, income from the same, as well as tax income. Again, dozens of techs in Civic Advances.
What About Research Efficiency?
There are a handful of techs that increase maximum research efficiency. The way research works is rather simple: your pops produce research points, and this is then compared to number of integrated pops. The final number gives you a percentage ratio. This then gives you a base number that each area of advances increases per month.
The first thing to do is to get the number to it’s maximum, which is 100%. Once you reach this, you need to increase it. Especially as you will quickly get ahead of time, which in turn slows down research.
However, this isn’t your first priority. And the reason is rather simple: these inventions come rather late in the Imperator: Rome tech tree. For example Embracing Philosophy is the last invention in Civic Advances. Another factor is the fact that the happier your pops are, the more research points they produce. So you want to get them happy first using other technologies. The exception to this is Tehological Colleges, which can be grabbed right after researching Great Temples.
Following techs increase research efficiency:
- Embracing Philosophy (Civic Advances)
- Stoicism (Requires Hellenistic as inegrated culture, found in Religious Advances)
- Book Binding (Oratory Advances)
- Theological Colleges (Religious Advances)
- Scribae (Religious Advances)
What About All The Other Techs?
Once you have picked your way through the above choices, you can start looking at the other techs. Except for naval Techs, which aren’t worth it until you literally have nothing else to use your points on. Overall, at this point the tech no longer makes a big difference.
In the military tree you might want to eventually work your way into Cohorts, which allows you to raise multiple legions. But this is a late-game concern, as it is levies that should always do most of the fighting.
