Good day fellow commander,

If you have played this game at least once, you know that there are quite a few upgrades you can research in Cossacks 3. A lot of them are pretty straightforward and don't require much explanation. However, there are some whose description does not fully cover what they do and sometimes it's not even clear when you have purchased them.

Well, look no further! Because in this guide, I will sum up a few of which I think lack description in hope I spare you some stupid in-game decisions.

The first section will cover a few basic mechanics, because they come back in the actual upgrades part, and then follows the upgrades list.

Because some upgrades involve these, I thought it would be best to clear them up first.

Cossacks has many soldier types that attack in different ways. Some (try to) poke their enemies to death with pikes or spears, other fill them with arrows, others with bullets, and of course, there is artillery which just ♥♥♥♥♥ up screws over everything that is not other artillery. But as much as soldiers deal damage, soldiers can also build up resistance to damage. I go over these 'resistances' and 'defences' in this section, because there was a question about it.

This is the basic 17th century pikeman, which is used by most civilizations. Underlined in red is the unit's damage and damage type, in this case 'pike' damage. In yellow is the (in this case faded) shield icon that represents bonus armor (see part one). Last is the green box, which are all the resistances the soldier has.



Damage
Damage is pretty straightforward: the number represents how much damage is inflicted with each attack (in this case, with each stab). There are six damage types related to units, from left to right: arrow, bullet, cannonball, grapeshot, pike, and sword


The first 4 are ranged, the last two melee. Bullet damage is damage dealt with muskets, arrows by (who would have guessed?) archers. Cannonball damage is inflicted by artillery (cannon, howitzer), navy (except the Galley's bombard attack), but also debris originating from destroyed buildings or those attacked by bombards. Grapeshot is inflicted by cannon at close range and the Multibarreled Cannon. Sword damage is inflicted by raiders (fast cavalry like the Hussar or the Sich Cossack) and certain infantry units (like the Roundshier), and lastly, pike damage is inflicted by bayonets, pikes, and heavy cavalry (like the Cuirassier). Soldiers' attack can be boosted with special 'training' upgrades available in the military buildings they are trained from. Most soldiers can receive a total of 6 of those upgrades whose effects stack.

Damage Resistance
When a soldier takes damage of a certain type (for example, gets stabbed by another pikeman), if the soldier has a resistance against the damage type, the number next to it represents how much damage exactly is ignored. In this case, If our pikeman gets hit by another basic pikeman (8 pike damage), he only takes 6 damage, because 2 damage is ignored due to his resistance. If he gets shot by a musketeer for 9 damage, his resistance of 5 against bullets reduces the hit to only 4 damage. If a soldier's resistance equals of even exceeds the damage of the incoming attack, he recieves only minimal damage (1). Six damage types means six damage resistances, and these are: arrows, bullet, cannonball, grapeshot, pikes, and swords


All soldiers can gain increased protection against swords, pikes, and arrows. This is achieved by funding training upgrades in the military buildings where they are trained, just as with their damage output. Most units have six of such training upgrades whose effects stack.

A word of advice: all armored soldiers are highly resistant to grapeshot.
Grapeshot is by far the biggest threat non-armored units can face, one well placed shot can literally kill hundreds in the blink of an eye. But armored units sometimes pretty much ignore it thanks to their high resistance. If you play as Ukraine, Algeria or Turkey, who lack standard armored units, and find yourself fighting against an opponent who abuses this, never forget that you can train Mercenary Roundshiers in the Diplomatic Centre! These are armored and can get close to these grapeshot monsters with ease, which will allow you to safely disable them!

Formations
A cool feature in Cossacks 3 is the ability to arrange soldiers of the same type in formations, allowing to manage large armies more easily. But aside from that, soldiers in formations have enhanced combat abilities. Cavalry and infantry arranged in formations gain a bonus to both armor and damage.
Cavalry receive a +1 bonus to both, no matter how big the formation. Infantry gain a +2, +3 when 400 units are in formation.
When infantry units in formation are put into the 'Stand ground' command, a loading bar will appear. Once the bar had filled, the 'Stand ground' is complete, and units receive a whopping +7 to both damage and armor (but can not move). Infantry in this combat formation can thus compete with (normally much stronger) cavalry units. Use infantry to hold your ground, and cavalry to take it!

Increased field capacity
Manufacture agricultural equipment (blacksmith).
Price: 400 wood, 100 gold

Carry out field melioration (academy)
Price: 1400 wood, 522 gold

The main food source in Cossacks is crops and crops grow around mills (obviously). There are two ways to make mills work more efficiëntly: by upgrading harvesting (increases the food value of each bag of flour your peasants carry to the mill or town center) and increasing capacity of the crop fields around it. Basically, a peasant can harvest only that much food from one crop field (one square) before it is depleted. Once a field is depleted you must resow it (which costs money for each individual field) so new crop can grow (which takes time). If you upgrade your field capacity, you can harvest much more food from your fields, meaning less expenses on resowing fields and less time wasted on waiting for them to grow. In the end, it means much more peasants can work the fields of a single mill, and you don't have to constantly look at it to make sure there are still enough crops to harvest. Trust me, it saves you a lot of frustration.

Flint lock
Design flintlock (academy)
Price: 3700 coal, 1550 gold

This upgrade is purely for 18th century musketeers, 17th century musketeers do not benefit from it. The flintlock upgrade 'decreases the cost of the musket by half'. The musket here are the iron and gold price of the musketeer. For the standard musketeers, it means lowering the iron/ gold price from 40 to 20 each. Since 18th century musks form the backbone of the late-game army, this is a very strong upgrade, especially since it is quite cheap.

Geology
Devellop geology (academy)
Price: 250 gold

Ores are very valuable and mines should be build pretty soon in the start of the game. Geology makes ore veins appear as yellow dots on the revealed (as in: what is visible to you) minimap. But it also allows you to find them in the invisible parts of the map without the need of a scout. Notice that over an ore vein, there is an icon hovering that tells you what kind of ore vein it is. With geology researched, if you scroll over ore veins located in the dark parts of the map, the icons are visible. Only 500 gold and it can save you a lot of time!

Medical science
Devellop medical science (academy)
Price: 200 coal, 200 gold

A tech that can be researched repeatedly and heals all soldiers that are not death by the time it is researched. The healed amount is about 150, so all your infantry is instantly at full health. This tech used to be very powerful and much more efficient than training actual healers, but since later patches the research time has been increased significantly, meaning that it can't be used as often anymore. Still, instantly healing all your infantry to full health is no joke and the price is respectable, make good use of it.


Finance artillery repair shops
Finance artillery repair shops
Price: 350 wood, 100 gold, 250 coal

Same as medical science, but for artillery. This used to be relatively useless in the past since cannon were either so tanky that they basically never got destroyed (cannon) or were fragile that they went down after one well placed cannon shot (I'm looking at you Howitzers!). But later patches reworked artillery drastically, and now it is actually kinda useful. Note that I rarely use it, since I personally hate artillery: they slow down an army (since they have low speed and can be captured when unguarded), can only be damaged by other artillery or ships, and their damage output against soldiers is disgusting.

Improve armored soldier's armor
Forge new cuirasses (blacksmith)
Price: 11950 gold, 3000 iron

Research improved steel grades for cuirasses (academy)
Price: 6950 gold

In general, you can divide cavalry and infantry units in two large groups: armored and non-armored units. How to tell apart an armored soldier from a non-armored soldier (if their appearance does not suffice)? If you compare an armored soldier with a non-armored soldier, you will notice that an untrained non-armored soldier does not start with a single resistance (with a few exceptions, f.e. the Algerian Mameluke), and can only gain resistance to three damage types: pikes, swords, and arrows (through training, see first section). Armored soldiers not only have a base resistance against those three (except 17th century officers), but also against musket bullets, cannonballs and grapeshot.
Now, if you take a look at an armored soldier's stats, you will notice that under the unit's damage type icon and its damage output, there is another icon: a faded shield. This represents bonus armor. If a unit recieved bonus armor from an upgrade (either or both of named upgrades), the shield becomes visible and a number will appear next to it. This number represents how much additional damage is blocked from each of the six damage types. So if you buy one upgrade, all armored soldiers take an additional 2 less damage from pikes, arrows, musket fire,..., and both together grant a total of 4 bonus armor. These upgrades only apply to infantry and cavalry. And take it from me: they may be expensive, but they are worth it. Especially increased resistance against musket fire greatly increases the surviveability of armored units, who often have to close the distance between them and their target before they can attack. Note that some ships (like the Ship of the Line) have bonus armor as well, making them resistant to fire arrows and grenades (but not so much against artillery).
If you play with a nation that has no armored units (f.e. Ukraine), these upgrades are not available.
It is also worth mentioning that bonus armor gained from arranging units in formations works similar, except that non-armored units also recieve the bonus.

Building armor
Forge metal armature and gratings (blacksmith)
Price: 350 gold, 19320 stone, 900 iron

Use new construction materials (academy)
Price: 13500 wood, 1150 gold, 8714 stone

Fact: a lot of buildings are expensive. Second fact: for most buildings, the next copy will be more expensive that the previous (for example, the price of a town center triples with each one you build). Only a few buildings do not follow this rule: Shipyards, mines, pallisades and walls (including gates) .Third fact: buildings that get destroyed collapse and bring forth an explosive rain of rubble, that is deadly to pretty much any unit that is at the wrong place at the wrong time, they are actually the equivalent of cannonballs. If you have a squad of soldiers packed against a building on fire and it collapses before they get the hell out, they will get decimated! Take home message: losing buildings will hurt. Luckily for you: 1) only a limited amount of units can destroy buildings, and 2) you can strenghten your buildings, making them take less damage. The mechanism of building armor is very similar of that for armored soldiers (see previous) for arrows (edit: and grenadiers' grenade attack): the number displayed is exactly the amount of damage that is ignored when a building is attacked with fire arrows. It works differently for artillery. I can't tell exact numbers, but just take from me that, if you buy both upgrades, mortars will still be a serious threat, howitzers have lost a lot of power but can still do substantial damage, and that cannons become completely useless (cannonballs have turned into pillows). Note that grenadiers are extremely efficiënt at destroying buildings after their last attack upgrade is researched in the 18th century barracks, dealing almost 1500 damage with each grenade.

Note that Towers and Walls do not benefit from these, because they are considered Fortifications, and have an upgrade specificly for themselves. Pallisades cannot receive additional bonuses.

Fire power upgrades
Improve firearms: rifled barrel (academy) => 10%
Price: 7000 gold

Research Granular gunpowder (academy) => 10 %
Price: 6000 gold

Research new sulphur purification methods (academy) => 15%
Price: 12000 gold

Research new nitre purification methods (academy) => 25%)
Price: 21000 gold

These upgrades used to be quite confusing, but thanks to the patch from 3rd february 2017, they have become much more 'user friendly'.
Before the patch, these upgrades had to be researched at the very end (after upgrading every musket wielding soldiers' fire power) and in specific sequences in order to maximize the fire power bonus they granted. But now these upgrades do not enhance the soldiers' fire power directly, but they act as a cumulative 'damage modifier'.
Here's how it works: in the beginning, you have your poor vanilla musketeers. They have had no practice shooting trainings yet (that are the fire power upgrades in the barracks) and since you are poor, no research has been done. At that point, his damage modifier for fire power is 100% (or just 1x fire power).
Then suddenly you find a huge chest of gold, enough to buy the strongest fire power upgrade (21k), and you research it. The 30% is not calculated from the soldiers' fire power that given moment (that was the old system), but is instead added to the damage modifier (100%+30% = 130%, or 1,3x fire power). If you now start training your soldiers in the barracks, first the training benefit is added to the base damage output, and then the damage modifier alters the result. The maximum damage modifier is the cumulative effect off all 4 upgrades (100% + 25% + 15% + 10% + 10% = 160%). This change means two things:
1) The sequence in which the upgrades are aquired does not matter
2) The Academy upgrades can be aquired before trainings in barracks/stables without the risk of lower gain in fire power

Am I happy with this change? You BET I AM!

Bayonet damage upgrades
Research new steel grades (academy)
Price: 432000 gold

This upgrade is for all soldiers wearing bayoneted muskets, being 18th century muskets and grenadiers, and enhances their melee damage output. Just like the fire power upgrades discussed earlier, this one used to be a bit tricky, since it required you to train your musketeers/grenadiers to the max for maximum benefit. But now it acts as a damage modifier as well, meaning that when purchased, the melee bonus of the bayonet increases with a factor x1.25. Since this tech is 1) jaw-dropping expensive, and 2) not very powerfull in the beginning, it's smarter to train at first. And don't forget that there are a couple of upgrades that enhance bayonet damage by adding a bonus instead of increasing a damage modifier. These are:

Forge bayonets and broadswords for infantry (blacksmith)
Price: 1300 wood, 1500 gold, 900 iron, 5000 coal

Design bayonet: barrel-inserted, bayonet with a tube (academy)
Price: 12750 gold

Welp, that's all I have to say for now. Now we just play the waiting game and hope that folks post some comments with maybe some good info I can integrate in this guide. Or maybe some of this info will be changed by future patches. Thank you for your interest, and good luck with your next battle!