Why is Ground Combat needed?
In future, orbiting spacecraft will be able to target and destroy ground forces that are not within a PDC. So why have ground forces then? Because PDC designers are likely to give their PDCs very thick armour that in many cases will be able to resist everything that orbiting spacecraft can throw at it while the PDC proceeds to blast those spacecraft out of the sky. However, PDC weapons are designed to engage spacecraft, not ground forces, so you will be able to use ground forces to assault and capture enemy PDCs. Any ground forces based within the PDC will be able to resist that attack with a considerable defensive bonus. A planetary assault under these circumstances will likely consist of fast spacecraft dashing in to drop troops while under fire from PDCs and then getting the hell out while the ground forces try and take out the PDCs. Attacking ground forces will have the option to concentrate their efforts on a specific PDC (based on sensor contacts) or fight a general action against enemy ground forces outside PDCs (if there are any).
Once hostile ground forces have been eliminated, either through ground combat or orbital bombardment, ground troops will be also needed to force a surrender through occupation
Ground Combat Units
Each Ground Combat Unit (GCU) has three main values. Attack Strength, Defence Strength and Morale. The first two are based on the Racial Ground Combat Strength (RGCS) while the latter is based on experience and training. The RGCS, which starts at 10, can be increased through research. Each type of ground unit uses a separate modification of the RGCS for attack and defence and if the RGCS increases, the strength of all ground combat units increases accordingly. The six types of ground combat unit are as follows:
? Heavy Assault (180 TP): This unit has both attack and defence strengths equal to the RGCS
? Mobile Infantry (100 TP): This unit has an attack strength equal to half the RGCS and a defence strength equal to the RGCS
? Assault Infantry (100 TP): This unit has an attack strength equal to the RGCS and a defence strength equal to half the RGCS
? Garrison (60 TP): This unit has no attack strength and a defence strength equal to the RGCS
? Engineer (200 TP): This unit has no attack strength and a defence strength equal to half the RGCS. However, while on a planet it acts as a construction factory for all purposes. The Engineer is to the Construction Factory as the Automated Mine is to the Mine.
? Headquarters (150 TP): This unit has no attack strength and a defence strength equal to one fifth of the RGCS. The sole purpose of a headquarters is to house a commander. The senior HQ commander in a PDC uses his ground combat bonus to affect all ground units within the PDC. The senior HQ commander on a planet that is not in a PDC uses his ground combat bonus to affect all ground units outside PDCs.
Ground Forces Training Facilities
Ground Units are produced by the Ground Forces Training Facility (GFTF). Each GFTF requires 2400 BPs and 2400 tons of Duranium and produces 100 training points per year. The GFTF tab on the Economic window is setup like the shipyard tab with each GFTF able to build one unit at a time. Although there is no research line to increase the amount of training points produced, the RGCS can be increased through research, effectively providing more combat strength from the same amount of training. All ground units require an amount of Duranium equal to one quarter their training cost and an amount of Neutronium equal to three quarters of their training cost.
Troop Transport Modules
All GCU are the same size. A ship needs one Troop Transport module to transport each GCU. GCU may only be moved from a ship to a planet, or vice versa, if the ship is in orbit. Troop Transport modules require 20 HS.
Combat
Any race with GCU on a planet can choose to attack ground units or PDCs of another race on the same planet. Note that attacking and defending are two different actions so the attacked race may decide to remain on the defensive and not counter-attack. If both sides attack each other, two separate combats are calculated. As the combat is potentially covering the entire planet, each combat round takes place during the five day increment. If time is advanced by more than five days, one combat round takes place for every 5 days in the increment.
Attacking ground forces will have the option to concentrate their efforts on a specific PDC (based on sensor contacts) or fight a general action against enemy ground forces outside PDCs (if there are any). This is accomplished by choosing which PDC or Population to attack on the Ground Units tab of the Economics window. If a PDC is under attack, only the defenders of that specific PDC are able to take part in the defensive battle. However, troops can emerge from other PDCs to fight an offensive action against the attackers in the field and try to destroy them. Obviously this won?t be a good idea if there are enemy spacecraft within weapon range. If the attackers are concentrating on a specific PDC, the defenders are able to move around between other PDCs but are not able to reinforce a PDC under attack. In addition, the PDC under attack may not reload its magazines from the planetary stockpile.
If a PDC is captured (i.e. all ground forces within it are eliminated), it becomes part of the attacking player?s forces. He can move troops in to garrison it and the defenders may try to recapture it. There may be a chance the defender will attempt to blow up the PDC or damage its systems before it is captured, depending on his racial characteristics.
Combat Ratio and Casualties
When an attack is carried out, the total attack strength of the attacker is compared to the total defence strength of the defender to create the Combat Ratio. For example, if Race A had an attack strength of 300 and Race B had a defence strength of 200, the Combat Ratio would be 300 / 200 = 1.5. Although defenders do have an advantage, this is already built into the attack and defence strengths of each unit type so the combat ratio is unaffected unless a PDC is involved. If the defenders are in a PDC, they gain a defensive multiplier equal to one third of the PDC?s armour. For example, defenders with a total defence strength of 50 within a PDC with 8 armour would have a modified defence strength of 50 x 8/3 = 133.33.
Each defending unit has a percentage chance of being destroyed equal to the Combat Ratio multiplied by 10. For example, if the Combat Ratio was 2.7, then every defending unit would have a 27% chance of being destroyed.
Each attacking unit has a percentage chance of being destroyed equal to 10 divided by the Combat Ratio. For example, if the Combat Ratio was 2.2 then each attacking unit would have a 10/2.2 = 4.5% chance of being destroyed. If the Combat Ratio was 0.4 then each attacking unit would have a 10/0.4 = 25% chance of being destroyed. Note that for a combat ratio of 1.0, both sides will have a ten percent chance of losing each unit.
HQ units have only half the normal chance to be destroyed as they will tend to be behind the lines. There are no damaged ground units in Aurora. They are either at full strength or they are destroyed.
Morale
Each GCU starts with a Morale of 100. As long as its morale stays at this level it has no effect on combat. If the morale is increased or decreased, it affects both the attack and defence strengths of the unit. The modifier is equal to Strength x (Morale/100). For example, a unit with 110 Morale would have attack and defence strengths 10 percent higher than normal. A unit with 80 Morale would have attack and defence strengths 20 percent less than normal. In addition, when the roll is made after combat to determine if a unit is lost, the chance of being destroyed is divided by the unit?s Morale/100. For example, if a unit with 120 Morale has a fifteen percent chance to be destroyed, the modified chance = 15% / (120/100) = 12.5%, so this unit has now only a 12.5% chance of being destroyed. This simulates that lower morale units are more likely to be destroyed than higher morale units.
Commanders
Officers may be assign to command a division or headquarters unit in the same way as they command a ship, a population or a fighter group. An officer?s Ground Combat Bonus improves the attack and defence strengths of any GCU to which he is assigned. In addition, the Ground Combat Bonus of the most senior HQ commander within a PDC will modify the combat strengths of all other units in that same PDC and the Ground Combat Bonus of the most senior HQ commander outside a PDC will modify the combat strengths of all other units outside of PDCs.
Supply
Ground Combat Units do not require any type of supply.
Occupation
If all PDCs and defending ground units are eliminated, the attacking player may be in a position to conquer and occupy the defending population. The required garrison strength is based on the defence strength of the occupying force. The garrison strength required to force a surrender is equal to:
Pop in millions * Racial Determination/100 * Racial Militancy/100
For example, if the defenders have a population of 400m, a Determination of 60 and a Militancy of 50, the required garrison strength will be: 400 * (60/100) * (50/100) = 120. Note that this is a minimum amount required to force a surrender. It may be desirable to station a larger force on the planet to avoid disruption to its production facilities.
When a population is conquered, there is a chance some tech will be recovered by the occupying forces. A check is made against every background tech known by the conquered race but not the conquering race. The percentage chance of learning each tech is equal to Pop in million/5. For example, conquering a pop of 200m will yield a 40% chance of learning each background tech known by the conquered race.
Steve
