The smallest military unit is called a cohort. A cohort is comprised of 1000 men; these 1000 men are subtracted from the manpower pool when the cohort is recruited. A number of cohorts can be grouped to form an army.
Cohorts are trained in cities at a cost of money, manpower and time. When a cohort is fully trained, an army is created to "house" it; or alternatively, the newly trained cohort will join an existing army if one is currently residing in the city, which the cohort is build.
Cohorts can usually be moved between Armies at any time for no cost.
All units types in Imperator: Rome have the same identical basic stats. These are:
- strength = All units start at 1000 strength, equivalent to the 1000 manpower it cost to build
- morale = 3.0
List of unit types
There are 9 types of land units. Only 2 of them are always available. Others can be acquired by having required resources or Military Traditions.
|Unit type||Monthly Upkeep||Build Requirements||Siege Assault||Movement
|Archers||4||45||0.21||none, always available||✔||2||1||+25%||−10%||−10%||−10%||+10%||−10%||+25%|
|Chariots||6||45||0.32||Military tradition: Barbarian or Indian||✘||2||1||+20%||−10%||−50%||−10%||−50%||+10%||+35%||−50%|
|Horse Archers||10||60||0.54||Steppe Horses||✘||4||5||+25%||+50%||+25%||−10%||+25%||−10%||+25%||−10%||+25%||−20%|
|Light Infantry||4||30||0.21||none, always available||✔||2||1||−25%||−50%||−10%||−10%||−25%||−25%||−50%||−25%|
- Siege Assault: Whether this unit type can assault forts.
- Movement speed: Speed in the map.
- Maneuver: How many squares away this unit type can target enemies on the Battle chess board. All land units have at least 1 maneuver so they can target at least 3 squares.
- Morale damage taken: Affects how fast the unit flees from combat. Also affects caused morale damage (scales with unit's morale)
- Strength damage taken: Affects how much manpower will be lost in combat. Also slightly affects all caused damage (scales with unit's strength).
- Attrition weight: Modifies the size of a unit for the purpose of determining whether the army exceeds the supply limit of the city it's in. This does not affect how many units can be transported by sea.
- Unit Type Icons: Multiplier for caused damage against that unit type.
Modifiers to unit types
- Discipline: Increases caused damage.
- Terrain bonus: Increases caused damage when fighting in a specific terrain.
- Offense: Increases caused damage.
- Defense: Reduces received damage.
- Morale: Increases caused morale damage and makes the unit stay longer in combat.
- Maintenance: Reduces upkeep costs.
- Starting experience: Increases initial experience when recruiting this unit.
Each cohort may also become loyal to a specific character giving +10% Discipline.