Ground battles are the most basic attack in war. They use 3 Military Action Points (MAPs), so you can gather enough MAPs for up to 4 ground battles per war in 24 hours. Ground battles use Soldiers and Tanks. To launch a ground battle, you need to have at least 50 soldiers on the offensive.
Your victory level determines how much money you can steal, how much resistance your opponent will lose, and the amount of damage done. If you achieve an Immense Triumph ground battle victory, you remove 10 Resistance and have a 10% chance of destroying an enemy City Improvement (excluding power plants).
To build Soldiers and Tanks, you need Barracks and Factories city improvements respectively. Soldiers fight more effectively with Munitions and Tanks require both Munitions and Gasoline to be used (both in offensive and defensive battles).
Achieving an Immense Triumph victory in a Ground Battle will result in you obtaining ground control over your opponent in the war. Ground Control is a war status that only one side of the war can have at a time. Once Ground Control has been established, all subsequent successful Ground Battles by the side with Ground Control will destroy some of the opponent's Aircraft.
The number of Tanks destroyed in a Ground Battle where the attacker has Ground Control is determined by the number of offensive Tanks sent into the battle, as well as the outcome victory type. In an Immense Triumph victory, the attacker will destroy 0.0075 enemy Aircraft per offensive Tank sent into the battle. In a Moderate Success victory, the attacker will destroy 0.005 enemy Aircraft per offensive Tank sent into the battle. In a Pyrrhic Victory, the attacker will destroy 0.0025 enemy Aircraft per offensive Tank sent into the battle. In the case of an Utter Failure victory type, no enemy aircraft will be destroyed.
Enemy Aircraft destroyed is always rounded down in the case where a fractional value is calculated.
Ground Control status can be ended in three ways:
Successful ground battles will result in money being stolen from the opponent, assuming they have money that can be stolen. The function which determines the amount of money stolen is dependent upon the number of attacking soldiers, tanks, the attacking nation's war policy, the defending nation's war policy, and the war type.
Defined in terms of variables, the formula which determines the maximum amount of loot stolen is:
SoldiersStolenMoney = Attacking Soldiers * 1.1
TanksStolenMoney = Attacking Tanks * 25.15
MaximumRandomFactor = 1.1
WarTypeFactor = 1
Note: If the war type is Ordinary, the WarTypeFactor = 0.5 and if the war type is Attrition the WarTypeFactor is 0.25
WarPolicyFactor = 1
Note: If the defender's war policy is Moneybags the WarPolicyFactor is 0.6. If the attacker's war policy is Pirate the WarPolicyFactor is 1.4. If both of these war policies are applicable, they cancel each other out and the WarPolicyFactor = 1
VictoryFactor = 3
MaxMoneyStolen = (SoldiersStolenMoney + TanksStolenMoney) * VictoryFactor * MaximumRandFactor * WarTypeFactor * WarPolicyFactor
In practice, the maximum loot possible is not likely to be the amount stolen in a ground battle. In reality, the MaximumRandomFactor is actually a random number generated in the range [0.8,1.1], and the VictoryFactor is determined by the type of war outcome (0 = Utter Failure, 1 = Pyrrhic Victory, 2 = Moderate Success, 3 = Immense Triumph).
Additionally, there are limitations set by how much money the target nation has. For example, you cannot steal more than 75% of the defending nation's cash on hand, nor can you steal their last $1,000,000.
The amount of damage done by a ground battle is dependent upon a number of factors. The base formula for infrastructure damage is:
Infrastructure Destroyed = MAX( MIN((Attacking Soldiers - (Defending Soldiers * 0.5) * 0.000606061 + (Attacking Tanks - (Defending Tanks * 0.5)) * 0.01) * RAND(0.85,1.05) * (Victory Type / 3), City's Infrastructure * 0.2 + 25), 0)
War Type and War Policy factors are multiplied to the base damage calculation. Victory Type is 0 for Utter Failure, 1 for Pyrrhic Victory, 2 for Moderate Success, and 3 for Immense Triumph.
Note: A defending nation will have a resisting population added to their ground army strength, which is equal to Population * 0.0025.
Army Value = Unarmed Soldiers * 1 + Armed Soldiers * 1.75 + Tanks * 40
ATSR = rand between 40% and 100% attacking soldier army value
DTSR = rand between 40% and 100% of defending soldier army value
ATTR = rand between 40% and 100% of attacking tank army value
DTTR = rand between 40% and 100% of attacking tank army value
AR = total attacking army value random roll
DR = total defensive army value random roll
If AR > DR then Attacker Tank Casualties += DR / 1650
If AR > DR then Defender Tank Casualties += AR / 1550
If AR <= DR then Attacker Tank Casualties += DR / 1550
If AR <= DR then Defender Tank Casualties += AR / 1650
Attacking Soldier Casualties += DR / 125
Defending Soldier Casualties += AR / 125
There are 3 rolls per battle. So to calculate min casualties you would assume lowest possible roll every time, for max the opposite.