Ground forces

Ground troops can be dropped on enemy colonies and take them over. They also provide a reduction in unrest (by, we must assume, shooting dissenters). In addition, Engineer brigades allow you to exploit Alien Ruins, provide industrial capacity and can assemble PDC elements.

All ground units are built at a Ground Force Training Facility. They require some minerals, but no supply. They cost a modest amount of wealth for upkeep.

Organisation

Up to four ground unit battalions can be organized in a brigade, and up to four brigades in a division. Similar to Naval Organisation and civilian Sector Commands, higher echelon HQs radiate so much wisdom that their subordinate units get a bonus of one quarter of the HQ commanders' skills. This affects ground combat and training. It is possible (but untested) that the commanding officer in a brigade or division HQ should have a higher rank than his subordinates to be effective.

 Division HQ
     - Brigade HQ
         - Battalion
         - Battalion
         - Battalion
         - Battalion
     - Brigade HQ
         - Battalion
         - Battalion
         - Battalion
         - Battalion
     - Brigade HQ
         ...
     - Brigade HQ
         ...

Ground Combat

(from a slightly outdated post by Steve)

Orbiting spacecraft are 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.

GFTFs can be moved to a different colony by freighters.

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 (except Engineer Brigades, which need five Transport modules). 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.

Note that for transport bays, the same rules for loading and unloading apply as for cargo holds, i.e. without a spaceport or cargo handling system, it might take your brigade two weeks to disembark on a hostile planet. That might do if the planet is not defended, but you'd better research combat drop technology if it is.

Combat Drops

Infantry loaded into drop pods can be combat dropped, which doesn't require any unloading time for them to hit the ground and begin fighting. There are battalion-sized and company-sized drop modules (for Marines), which have to be researched first.

You don't need troop bays, but troops held in drop modules will lose morale over time. So you'll want to move them around in troop bays and only transfer them to drop modules when you need to. Don't forget to include Cargo Handling Systems on the transports because troops begin to lose morale as soon as the transfer to drop modules begins. Note that a battalion-sized drop module fits nicely in a FAC.

How To Combat Drop

1) Go to the F12 task group screen, select a Ship with Combat Drop Modules, click load GU into Drop Module in fleet. You should see a selection of units to load into the unit right below the Plotted Move screen called "Select Ground Unit" appear. Select one and hit Add Move. 2) Advance time till this is complete (takes time to load GUs into the drop pods but they exit the drop pods instantly). 3) Your unit should now be loaded onto a Combat module. 4) Now when you get near a planet or ship, you can select an action for this ship called Combat Drop Ground Unit, or Boarding Action.

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 five 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 assigned 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.

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.

Stats for Ground Units

• Type, The type of unit. Different types, AST, BHQ, DHQ, ENG, GAR, HVA, LTA, LTI, MAR, MRC, INF, REP, ICD, ACD,, and more. Base attack and def stats are determined by the type, and Racial Ground Combat Strength (RGCS). Morale is based on the experience and training of the unit.
• Atk, Attack
• Def, Defense
• Read., Readiness
• Morale, Morale
• GCB, Ground Combat Bonus, given by commanding officers

To train different ground units, they need to be placed under the command of a headquarter. Training will then start and morale will increase, if the HQ has a suitable leader assigned.

Ground Unit Types (5.52)

Unit Name	Type	Atk	Def	Size	TP
Assault Infantry Battalion	AST	100%	50%	5	100
Brigade Headquarters	BHQ	0%	20%	5	150	†
Divisional Headquarters	DHQ	0%	30%	5	250	†
Engineer Brigade	ENG	0%	50%	25	150	††
Garrision Battalion	GAR	0%	100%	5	60
Heavy Assault Battalion	HVA	120%	120%	5	180
Low Tech Armor Division	LTA	30%	30%	50	90	*
Low Tech Infantry Division	LIT	12.5%	25%	50	50	*
Infantry Cadre	ICD	1%	1%	5		**
Armor Cadre	ACD	1%	1%	5		**
Marine Battalion	MAR	100%	100%	5	180	‡
Marine Company	MRC	20%	20%	1	36	‡
Mobile Infantry Battalion	INF	50%	100%	5	100
Replacement Battalion	REP	0%	5%	5	40	‡‡

†: Brigade Headquarters may command up to four battalions forming a brigade. A Divisional Headquarters may command up to four brigades at a time.
††: Engineer Brigades act as a construction factory while on a planet. They are also required to recover abandoned faculties from alien ruins. Engineer Brigades are five times bigger than battalions and cannot be split up.
‡: Marines fight at double their listed strength when performing boarding actions against ships and PDCs.
*: Low Tech Infantry and Armor Divisions maybe be converted into Infantry and Armor Cadres respectively.
**: Infantry and Armor Cadres may be used to reduce the cost of training a new unit. Infantry Cadres reduce the price by 40 and Armor by 60.
‡‡: Replacement Battalions will help wounded ground units on the same planet recover to full strength at a cost to their own health.

See also: Ground Forces: Transportation, New units, Boarding Combat

How To Transport

Bring a ship over to a planet or another ship with troop transport bays. Select the ship you want to load from and select Load GU into Troop Transport. You select the Ground units you want to add from the selection box that fits into the screen one by one.

Note that for transport bays, the same rules for loading and unloading apply as for cargo holds, i.e. without a spaceport or cargo handling system, it might take your brigade two weeks to disembark on a hostile planet. That might do if the planet is not defended, but you'd better research combat drop technology if it is.

Ship Boarding

The ability for drop modules to be shot toward an enemy ship and get infantry onto the hull of that vessel. Infantry then begin blowing holes into the armor to enter the ship if none already exist.

Important facts about Boarding Combat

Trying to board a ship moving at several hundred or several thousand kilometers per second in this manner is still incredibly risky. Because of the speeds involved, the intercepting vessel must have a huge speed advantage to make the boarding attempt without suffering heavy casualties among the boarders. The cause of those casualties will vary but could include missing the target and ending up within the exhaust plume, impacting the hull at too high a speed, missing entirely and being lost in space, etc. The percentage of casualties from the boarding attempt is equal to 20xD10, giving a range from 20-200%. However, the amount of D10 rolled is reduced by Interception Speed / Target Speed. For example, if the interception speed is 6000 km/s and the target is moving at 1000 km/s, the number of D10 is reduced by 6. Therefore, if the intercepting ship is at least twenty times faster than the target ship, the attempt is automatically successful and no casualties are suffered during the boarding. Because of the risks involved, in most cases before a boarding attempt can be made the target ship will have to be slowed down or disabled.

1) Combat takes place every five minutes after movement and combat. Once a unit has successfully boarded a hostile vessel, the Boarding

Combat Clock begins counting. Once it reaches 300 seconds or greater, a round of boarding combat is fought and the clock is reduced by 300.

2) Low readiness units on both sides cannot avoid combat

3) The boarders cannot retreat so they must keep attacking until they capture the ship, die trying or surrender.

4) As a result of the boarding combat, collateral damage may be inflicted to the ship itself. If this is severe enough, or causes secondary explosions, it is possible the ship might blow up in the midst of the fight.

5) If all the defending units and crew are eliminated, the ship is captured.

How To Use

First you need a much faster ship than the ship you plan to try to take over. This is achieved via the small Drop Module and a fighter with an engine and a little bit of fuel and a tiny engineering section.

Load GU into Drop Modules within fleet (if fighter is in a fleet). Then select an enemy ship and issue a boarding order.

The Troop Shuttle will carry the troops from the fleet over to the enemy vessel and barring any accidents like the enemy blowing a 80cm hole in the troop ship you are all set for the shuttle to launch its troops at the enemy vessel and begin boarding actions.

The faster your Troop Shuttle is, the better the chance that more Marines will land on the enemy ship and giving you a better chance to take it over successfully.