Each level of the Infantry Barracks increases the Training Capacity of the building.
Levels 1-4: +100 Training Capacity Levels 5-20: +400 Training Capacity
In game Quote:You can't miss your infantry barracks. It's the structure that looks like a pentagon, filled with low buildings that have the latest in communications (pigeons). Everywhere you look there are wide squares, with young men marching, under the strict directions of their corporals and sergeants. On every one of the five walls there is a huge depiction of our Emperor, may he live forever, with his eyes looking down upon the young recruits with one finger pointed decidedly at them. Under the poster in the spirit of these times, there is a sign decorated with olive branches angels saying, "The Empire needs you!" The bottom line is: Every villager that passes through these gates will become a well oiled war machine if given the proper time.