Put one (two*) action cube on the area of your player mat, where you plan to recruit. Recruit / hire / build units of one type up to the number of respective buildings you have constructed. Pay for every unit and place them in your city, or your castle, or a hex adjacent to your city / castle. But keep in mind the rules of placing the unit - ground units should be on land, vessels should be on water.
In your turn, while choosing the recruitment as your main action, you can recruit several times, the same or different units, spending action cubes each time. By reusing the same area, you can recruit a different type of unit there.
[*] If there are any action cubes on this area, thus you have already recruited there this round, place two action cubes to recruit in that area again.
Units can be recruited if only you have them in your supply.
If you play for a certain nation, recruit your elite units in castles.
Siege machines, galleys and elite units can be recruited starting from age II, and only trebuchets - from age ІІІ.
The city of Laura is threatened by the army of Mike nearby. That is why she decides to choose recruitment as the main action of her turn. She has two barracks and one workshop constructed. She understands she has to protect her city before Mike attacks.
Laura puts one action cube on barracks, pays 2 
+ 2 
+ 4 
and recruits 2 archer units. She places them in her city. She maneuvers them as her free action - puts one depletion cube on her city and attacks Mike's army.
Laura is not quite satisfied with the result of the battle, so as a part of her main action (recruitment), she puts an action cube on her workshop area, pays 1 
+ 1 + 5 and makes one ballista to reinforce her garrison.
Ballista cannot attack, as there is a depletion cube in the city it is placed at. Therefore, she passes the move to the next player.
