GITM Combat Strength Modifiers

A unit's basic combat value is its strength, modified as follows:
 
Combat Arm:  
Arm Modifier
Infantry None
Light Infantry None
Heavy Cavalry x4 (x0.5 in fort)
Medium Cavalry x2.5 (x0.75 in fort)
Light Cavalry x1.5 (x0.5 in fort)
Heavy Artillery x12
Medium Artillery x9
Light Artillery x6
Siege Artillery
 x6 in field combat
x24 in bombard
Militia x0.75 in a city square, else x0.5

In general, the strength of a brigade is equal to its manpower as modified by the above chart. A cavalry or infantry brigade with a battery attached has 100 of its men modified as artillerists and the rest of its strength modified by the brigade type. Artillery attached to infantry brigades is medium artillery; artillery attached to cavalry brigades is light. Artillery brigades must have at least 50 men to fire one battery. Artillery brigades with fewer than 50 men fight as poorly armed infantry and are modified as x0.5. Artillery brigades can use up to 100 men per battery. Artillery brigades with more than 100 men per battery have 100 men for each battery modified as artillerists and the rest modified as x0.5. All other artillery brigades have strength equal to their manpower as modified by the above chart.


Combat Attitude:  
Attitude Strength modifier Casualty modifier
Assault/last-ditch +20% +20%
Attack/defend 0 0
Skirmish Light infantry -30%, others -50% -50%
Evade -90% -80%

Tactical Square Defensive Rating:  
Defensive rating Defender's modification
0 -30%
1 -20%
2 -10%
3 0
4 +10%

Fort Rating (melee strength only)
Fort level
 Defender's modification
1
 +50%
2
 +100%
3
 +200%
4
 +300%
5
 +400%

Defenders must have men present equal to at least 1/3 the capacity of the fort to receive the bonus. Example: when defending a fort of capacity 8000, defenders get a bonus if 3000 men are present, not if 2000 men are present.		 Unit Quality:  
Quality Modifier
Excellent +30%
Very Good +20%
Good +10%
Average
 0
Fair -10%
Poor -20%
Very Poor
 -30%

Unit Experience:
Exp Modifier Exp Modifier Exp Modifier
0 -40% 9-15
 -10%
 36-48
 +20%
1-3 -30% 16-24
 0
 49-63
 +30%
4-8 -20%
 25-35
 +10%
 64+
 +40%

Unit Morale:
Bonus is equal to (unit morale-50)/3. For example: morale of 50 gives no change, morale of 80 gives 10% bonus, morale of 20 gives 10% penalty.

Terrain:  
Terrain Modifier
Hills/high hills Artillery +25%, cavalry -33%, light infantry +10%
Mountain pass Artillery +25%, cavalry -33%, light infantry +10%
River ford Light infantry +10%
Forest Cavalry -50%, line infantry -20%,
light artillery -33%, other artillery -50%
City/village Cavalry -50%, artillery -20%

Battle Line Modifiers:
  Firing Phase Melee Phase
Front Line Cavalry: Does not fire None
Second Line Infantry: Does not fire
Cavalry: Does not fire
Artillery: +50% 		Infantry: +10%
Cavalry: +10%
Artillery: +50%
Rear Line All branches: Does not fire Infantry: -50%
Artillery: -50%

(Battle line modifiers do not apply to bombardment)

Other Modifiers:

Tactical movement during the same tactical phase as the battle: siege artillery -75%, other artillery -20%, cavalry +25%, militia -33%, in forest terrain -20% (all branches)

Climbing hill into battle: -20%

Fatigue: If fatigue>6, x6/fatigue level

Out of ammunition: infantry -50%, artillery -90%

One flank turned: -20% [ melee only, not in forts ]
Both flanks turned: -40% [ melee only, not in forts ]

Friendly artillery firing: +10% for infantry and cavalry

Mixed order bonus (between 33% and 67% of modified strength
from cavalry): +33% (not in forts)

Infantry in square: x2.5 against cavalry [ melee only ]

Artillery in bombardment: +50%