"Barracks" refers to the buildings where low-end military units are created. Generally speaking, all players start off with a Drill Square, represented by two tents and a stockpile of munitions nearby. In the Mechanical Era, the Drill Square is subsequently converted to Quonset Huts, but the units trained remain the same.
The Barracks allows the creation of low-end infantry and light cavalry, as well as irregular forces such as scouts and commandos.
- Crossbowmen/Archers  Skirmishers/Musket Cacique  => Marksmen  (Becomes part of line infantry line thereafter)
- Arquebusiers /Javelineers  => Musketeers  => Line Infantry  => Rifle Infantry 
- Pikemen  => (Becomes part of grenadier line thereafter, or Heavy Pikemen for factions such as Mexico and Sweden)
- Scouts [1-2] => Commandos [3-5]
- Hussar  => Guard Hussars  => Regimental Hussars  => Light Cavalry  (only available if cuirassiers area available)
South Asian and New World factionsEdit
Some factions do not have access to gunpowder units. Instead, they tend to have javelin units and spearmen. Javelin units are distinguishable from arquebusiers in that they have a lower range, but no minimum range, meaning that they can send their javelins into the enemy from close up.
The harquebusier, additionally, while it has a better range and attack than javelin men, must deploy first before attacking. While deployed as such, the unit cannot move, and in this manner is vulnerable to melee units.
Archers become skirmishers, and while they are slow on foot, they have the best range and attack, making them useful as "human artillery", especially against heavy infantry. Non-western factions are stuck with archers until the Imperial Era, when they are subsumed into the line infantry line. For the Turks and Indians, this happens when Azzars are accessed for the Turks, and when Fusiliers become available for the Indians.
Unique units trainedEdit
- Dadao infantry  => Manchu matchlock  => Manchu musketeer  Manchu rifle  Less range than other musket units, but cheap and fast to create. The Dadao infantry is a non-ranged unit with a big sword.
- Matchlock ashigaru => [1&2] => ashigaru retainer  Japanese bushi are fast-moving gunpowder units.
- Azap sword => Azap matchlock => Azap musketeer  =>
*Balam slingers  => Royal Balamob slingers  - Balam slingers are similar to other javelineers, but can be cloaked
- Atl-atls  => Royal atl-atls 
- Tercio harquebusier =>  => Yellow Guards  high resistance to attrition and plenty of hitpoints
- streltsy musketeers  =>Petrine pekhots  => Imperial Pekhots  => Rifle Pekhots 
- Javelineer  => Heavy javelineers 
- Fire Tiger musketeers  => Black Flag regiment [3 & 4]
- Landwehrs  => Schutzen  => Royal rifle regiments 
- Kings's Foot  => Colonials  => Old Contemptibles 
- Libertador musket 
- Bersaglieri =>  => Bersaglieri Corps  weak, but with very good range and attack!
- Bedouin infantry 
- Iturbide's regulars 
- Landwehrs  => Schutzen  => Royal rifle regiments  => Kaiserliche Jagdbatallion 
- Doughboys  light infantry
- Mon conscript horse  => Taungoo cavalry guards  Konbaung lancers  => Konbaung dragoons  Light cavalry with the ability to intercept and destroy elephants.
- Camels  A unique conscript cavalry unit. Available from the start from your Drill Square.
- Armenian raider => Cossacks  => Don Cossacks  => Black Sea Cossacks 
- Llaneros  => Llaneros cavalry 
Archers and skirmish infantryEdit
- Genoese irregulars  => Marine snipers [2-3] (reforms as Bersaglieri infantry)
- Balam skirmisher  Balam skirmishers have better LOS than other units, and also come cloaked.
- Goumiers [2-5]
- Matchlock  (replaces the Mercantile skirmisher for various non-Western factions)
- Pandur  => Veteran Pandur 
- milicia honorada  a skirmisher unit.
- Rajput matchlock 
- Apache skirmisher [2 & 3]
- streltsy pike  => Opolchenies [2-4]
- Roundshielder swordsmen 
- Rodeleros 
- Escudados 
Hints and tipsEdit
Line infantry are medium infantry, and are the backbone of your forces. Initally consisting of pike levy and arquebusiers, these units give way to musketeers and riflemen (for most) while the pike levy are subsumed into grenadiers. Musketeers are weak in they have a minimum range until , and arquebusiers are worse off, having to deploy first before firing. Nevertheless, these units, along with grenadiers, make up the fastest infantry units in existence.
Archers and skirmishers are light infantry, and are mostly meant to function as a screening force and counter grenadiers. They are crack shots with arrows, muskets and rifles, but extremely subceptible even to Muslim horse levies.
Javelineers are not as good as arquebusiers, having a limited range. However, their lack of minmum range means that they are somewhat useful against melee units, although other factors will often play against them. Nevertheless, they are as fast as normal musketeers, and so they are useful in their own way.
Light cavalry are the cheapest and weakest type of cavalry, but thankfully are strong and fast enough for screening, reconaissance, and charging isolated enemy infantry, although most melee units will knacker most of them. Unhappily, most European factions are initally deficient in light cavalry (Asian factions prefer medium cavalry, which are a balance between light and heavy cavalry), and must rely on the expensive but fast-training merchant cavalrymen for a light cavalry arm. This is the case for most factions until hussars are available in the Mercantile Era.