A high level update on the new ground combat system. This isn't really about the detail, as I am still sorting that out, but more about some of the overall concepts.
One big constraint will be the question of upgrades.
That is to say, will the system work on the old VB6 system where researching a tech caused an empire wide instant upgrade in combat capacity, or will it become like with ships and stations, where you need to put a unit back into a Ground Forces Training Facility to upgrade their equipment, or convert them to cadre?
If it's the latter it might end up a little expensive if large ground armies become a thing.
My direction at the moment is to have a component system for ground unit design (which will replace all existing units including Titans). There are four base unit types (Infantry, Vehicle, Combat Walker, Aircraft), each of which has several sub-types based on the level of armour. 'Combat Walker' in this context is down to player interpretation. Could be a WH40K Titan or a Star Wars AT-AT, etc.). At the moment, my list comprises:
*snip unit type list*
You are missing wet navy units. While this could also be done through a component rather than a unit type, the usefulness of wet navy units should not be underestimated, especially submersible units. Planets are big so a single unit can be hard to find, but planets with a large hydrosphere extent have plenty of places for a submarine to hide also, and those are even harder to trace. The exact mechanics are up to you, of course, but I was thinking a variable combat modifier depending on the hydrosphere extent of the relative body, and severe penalties actually doing damage against a wet navy unit without some form of ASW equipped unit on planet.
With this more involved may also become interesting to consider the concept of under water infrastructure, low gravity infrastructure, and the effects such concepts have on ground warfare. While this should not increase the maximum population capacity of a planet beyond its maximum, it may impact how much population capacity is closed off by excessively large hydrospheres, for example.
Finally, because otherwise there's no point to 4th level ground commanders, I propose a Planetary Defense Command unit type (chosen specifically so the acronym is confusing to old players) commanded by a 4th level commander. In the case of multiple PDCs on planet the one with the senior most commander leads the defenses.
The armour strength (ARM) is a baseline, which is modified by the best available racial armour tech. So, an advanced civilisation may have 'light' vehicles with better armour than the 'medium' or even 'heavy' vehicles of a lower tech civilisation.
This is quite realistic.
Each base type has 1-3 component slots (Infantry 1, Vehicles & Aircraft 2, Walkers 3). This components can be combat-related or support-related. This list (so far) includes: *snip list of components*
A 'seaborne,' 'transport' or 'submersible' component would be quite appropriate, as might be a 'special forces' component for infantry. Also, I'm making a guess here but an Orbital Fire Support Controller should probably be needed for targeting ground troops that's not as likely to get your own units killed as those of the enemy, as well as limiting facility damage.
So for example, you could create a 'Medium Tank' using a Medium Vehicle with Medium Anti Vehicle and Medium Anti-Personnel. Or a 'Tank Destroyer' by going heavy armour and double anti-vehicle, etc.. The non-combat related functions will function in a similar way to now. Logistics will be a ground unit that is slowly consumed over time by other friendly units, acting as a form of ground unit supply. Orbital Fire Support Controller will be able to direct the fire of ships in orbit to support ground forces.
Will logistics units be consumed on friendly planets/ships? Because that would be a micromanagement bother.
The light, medium, heavy concepts for weapons are based on rate of fire and armour penetration. So a light weapon will fire more often and therefore engage more targets, while a heavier weapon will fire more slowly but have a higher chance of destroying the target. Essentially, you will need light weapons against numerous, lightly armoured targets and heavy weapons against armoured opponents. Penetration and rate of fire will also be affected by base racial technology in weapons and capacitor recharge rates. I might combine some of the anti-personnel and anti-vehicle descriptions as (for example) heavy anti-personnel and light anti-vehicle may not be that different.
When it comes to infantry weaponry, the major division between light, medium and heavy equipment is how much it actually weighs, rather than rate of fire and accuracy, generally speaking, if you hit someone with a bullet he's either dead or combat ineffective, while portable anti tank and anti air weapons tend to hit harder and further as they get heavier. Technology has evolved to the point that for infantry the question isn't one of rate of fire as much as how much they can physically carry with them.
For vehicles, the question is mostly one of combat endurance and cost. Heavier weapons are more expensive to field and will have less munition to fire. This imposes a heavier logistical burden.
Also, the line between heavy anti personnel weaponry and light anti vehicle weaponry is rather blurred. Most weapons that will destroy or heavily damage lightly armoured or unarmoured vehicles are perfectly serviceable in an anti personnel role, and often employed in such a role for extra range or to deal with infantry in particularly good cover.
This paradigm might change in the face of Trans-Newtonian technology of course.
Ground combat will now take place in the same time frame as ship combat, with each unit firing at specified intervals (except that time won't slow for ground combat - it will instead run multiple cycles depending on turn length). It will still take a while for ground combat though as hit chances will be very low.
I foresee turns sometimes taking very long times as NPRs try to deal with ground combat in a far of corner of the galaxy.
Ground unit design will have an individual unit type and a formation type. For example, you might design an 'Armoured Battalion' formation with the unit type as the 'Panther Tank'. There will be a set number of units within a formation and they will fire and take damage individually. So you may start with 50 Panther Tanks in each Armoured Battalion but after combat, some will be damaged and some destroyed. These can be repaired or replaced. Each unit will have a size, so the size of a formation will be number of units x unit size. I haven't decided yet whether to allow units of any size or have a 'battalion size' and have a number of units that will fit within that size. In the case of the former, then Brigade HQs would have a total command size, rather than commanding a set number of units. This would also allow minor units, such as a mortar company (light infantry - light bombardment) held at Brigade level.
I would advise in the case of a 'command size' paradigm that you allow HQ units to have a 'command size' for total maximum number of companies under their command, including lower level subordinate HQ companies and their assets, and a smaller 'Division/Brigade/Battalion level asset' limit. PDCs as I propose them have no command size limit but a very strict PDC asset limit to indicate the companies dedicated to their physical protection. This may cause some degree of havoc when it comes to designing troop transports though.
Likewise for organizational reasons I think it's best to stick to a 'battalion/HQ level' training paradigm. A unit that's converted to cadre will leave their equipment behind (1 ton transport capacity required per build point to ship, reclaimable like most equipment) and can either be assigned to a GFTF for training with new equipment compatible with the cadre, offering a small discount depending on cadre type, or used to create a new unit with an equipment pile in a month. This would also mean that construction/ordnance/fighter factories can produce ground equipment to shorten training times similar to how construction factories can build ship components to shorten shipyard construction time.
Within combat, each formation can be placed in one of four positions. Advance, Front-line, Support or Rear Echelon (names might changes). The default position for any formation is Front-line. Front-line formations will engage in direct combat and can be given orders regarding the type of enemy unit to target (as combat takes place, information will be provided about the base types of enemy units engaged).
A number of formations not exceeding the number of front lines units can be placed in the Support position. This would typically be bombardment or headquarters units, or a resting combat formation. Any ground-based unit (infantry, vehicle, combat walker) in the support position can use its bombardment strength against enemy units in the opposing front-line position or may be allocated to counter-battery fire against enemy units bombarding from a support position.
A number of formations not exceeding the number of support units can be placed in the Rear Echelon position. This would typically be aircraft, ground-to-orbit, logistics, repair or replacement units. Any aircraft in any position can target any enemy position, although it can be engaged by each position which it attacks or passes over. So an aircraft attacking the support units of an enemy can be engaged by anti-air units in the front-line or support positions I will probably make this any anti-air unit in the same hierarchy (divisional or brigade).
A number of Vehicle or Combat Walker formations may be assigned to the Advance position. This cannot exceed the number of front-line units. These formations are attempting to break through the enemy front-line formations. If they can maintain their advance position for a certain amount of time (TBD) without being forced to withdraw (withdrawal will be based on casualties and formation morale), they will be considered to have broken through the enemy lines and will be able to either attack support formations directly, or attack front-line formations with double strength (flanking them). After another specified amount of time (TBD), they can also choose to attack rear echelon units directly, or support units / front-line units at double strength. Any unit in an advance position will be identified by name and type to the enemy and can be attacked specifically (as opposed to just targeting a position).
Given our inability to micromanage ground combat to the same extent as space combat we should be able to define 2 stances from 3 different sets of stances. These sets are Offensive, Defensive and Miscellaneous. These stances determine what the ground commanders emphasize, offering certain bonuses and penalties based on where the focus lies. Rock/Paper/Scissors mechanics single out certain stances as being more or less effective against specific other stances. A 'Hardened Line' defense stance for example might be very good against a 'Massed Assault' offensive stance but weak against a 'Spearpoint Assault' offensive stance, while 'Spearpoint Assault' is poor against a 'Defense in Depth' defensive stance. You may want to raid Hearts of Iron's tactics system for ideas and/or names.
Miscellaneous stances aren't directly part of the rock paper scissors system, but modify things like fortification speed, unit replacement, supply and a few other things.
With the reworking of the ground combat mechanics there's also no reason to stick to the offense/defense divide as previously, where some unit types were very cheap and effective defense but useless on the attack (hello Garrison Battalions).
Infantry formations can be fortified. This can done to a minimal level by the formation itself, given sufficient time, or enhanced further by combat engineer units. This will greatly improve the formation's resistance to damage.
Likewise fortifiable are HQ units and CIWS/Ground-to-Orbit units, as these are units likely to stay in one place for extended periods of time. Fortifications should however be capable of being demolished in general combat, or more rapidly by enemy combat engineers/heavy bombardment units.
CIWS and Ground to Orbit units will be based on existing naval weapons, along with sufficient costs for reactors, fire control, etc.. They will not be able to attack in ground combat but will defend based on their base unit type.
This can get kinda broken if this means that Heavy Walker GtO units have a way to strike back instead of just being able to ignore being attacked.
In addition to the components, units will also have abilities that modify their cost and their combat strength in different circumstances. This will include boarding combat, extreme temperature combat, mountainous terrain, ocean terrain, etc.
Sensible, and some of my ideas on unit type and component would perhaps better fit here.
Garrison Strength will be heavily based on the number of units in a formation, so a light infantry formation, will be a more effective garrison unit than a heavy armour formation, despite being considerably cheaper.
A squad of boots on the ground right in front of someone does tend to leave more of an impression than hearing there's a tank 500 kilometers away.