Quote from: pedter on April 02, 2024, 05:26:38 PM

Any weapon, like the 10cm railguns in the large analysis post above, that is deep enough into falloff range to only hit one damage also work just as well.

Categorically not true.

Those are 0km orbital bombardment support rules, i.e. forward fire direction. If you consider gauss and 10cm railgun range to be a concern, then neither of us are discussing bombardment support and falloff is absolutely a consideration when shelling STOs from range. Please use Orbital Bombardment instead.

Quote

The damage in ground combat for an energy weapon is equal to 20x the square root of its point blank damage in ship-to-ship combat. Armour penetration is equal to half the damage. Fractions are retained.

Emphasis mine.

This is, again, for 0km bombardment support. While the long-range orbital bombardment rules do not reference beam damage at range, I assure you that weapons deep in falloff do not use their point blank damage (nor should they) for long-range, unguided orbital bombardment. The same mathematics for ground combat AP and damage do still apply at any range, so while one of my 10cm lasers at 0km applies 3 ship-to-ship damage for 17.3AP/34.6dmg, the same 10cm laser at 150kkm applies 1 ship-to-ship damage for 10AP/20dmg and lowers dust generation accordingly.

Quote from: pedter on April 02, 2024, 05:26:38 PM

Gauss are perfect at any range they can hit while both railguns and lasers, assuming they're a small enough caliber that the fire control can put them deep enough into falloff to only hit one damage, also work great. Meson and carronades would also do but particles, missiles, and I assume microwaves would not.

The problem with Gauss, 10cm railguns, etc. is that they usually have much shorter range than the anti-ship STOs you're trying to blow up, so you will tend to take a lot of extra damage or at least have to rotate ships out to recharge their shields often enough to become a micromanagement headache. Mesons and particle beams are the only weapons which can combine low damage per shot with high range, barring such a massive tech advantage over the enemy that 90% of this discussion doesn't matter.

I've only seen STOs come in three flavors: lasers, lances, and gauss. Lasers take heavy falloff, lances are dangerous, and gauss can only do a bit of sand blasting. My experience with each is to apply relatively matched counters to avoid micromanagement:
- My 150kkm laser PD turrets put laser STOs deep enough into falloff that the shields can shoulder the rest without much, if any, micromanagement. However, given their MSP burn, I suggest railguns (see next)
- Lance STOs are rough at any range; I like to sit outside of their range with a railgun caliber just large enough to apply 1 damage from slightly further away.
- Gauss STOs lack the weight of fire that fleet-based gauss PD possesses; stepping into their range for even one 5sec increment to exchange gauss fire leaves the gauss STO too crippled to continue.

For scale, 40kt of my laser PD hull is lucky to kill one STO per increment. The same 40kt of my gauss PD hull typically scores +/-12 STO kills per increment. The shields need only take a few gauss STO hits and thankfully gauss STO lack the sustained output given their losses to do more than beat up the shields and maybe tickle the paint.

Side note on particle beams: they bottom out at 2dmg so they'll still kick up more dust than even a meson would. They're also stupidly expensive to fire (ask me about my lance hulls, ugh); I'm still not convinced that firing failures are working as documented but I've been too lazy to collect the data.

Quote from: pedter on April 02, 2024, 05:26:38 PM

Bombardment hit chance excludes down-sized gauss odds for some reason so 17% gauss turrets kill an order of magnitude more STO per ton than anything else

An interesting mechanical glitch I've never heard of. Has anyone else seen this? Seems unintended but I can see how the mechanics as written could accidentally ignore the reduced-size Gauss %CTH malus.

On the other hand, fire control range does not change hit chance either as their anti-STO hulls pull range; it appears that any anti-ship or anti-missile motion tracking can be ignored when firing at static planetary locations. Perhaps it is appropriate to ignore down-sized gauss odds the same as ignoring long-range fire control odds.

Plus of course the shots from all the mesons which miss. Still lowest collateral I agree, although sadly I have not researched meson guns

Any weapon, like the 10cm railguns in the large analysis post above, that is deep enough into falloff range to only hit one damage also work just as well. Gauss are perfect at any range they can hit while both railguns and lasers, assuming they're a small enough caliber that the fire control can put them deep enough into falloff to only hit one damage, also work great. Meson and carronades would also do but particles, missiles, and I assume microwaves would not.

I usually leverage my 10cm PD laser turrets at 150kkm to clear out any particularly deadly STO then press my face to the glass and use my gauss PD turrets at 40kkm to wipe out every STO very rapidly. Bombardment hit chance excludes down-sized gauss odds for some reason so 17% gauss turrets kill an order of magnitude more STO per ton than anything else (except maybe railguns because their projectiles split) because of both down-sizing and rate of fire tech. They're both beams so no fallout and very little dust gets kicked up; the dust usually settles within a couple months as is clears at 250/year.

Mesons are probably the lowest "collateral" damage weapon there is, basically don't need any overkill at all, so whatever the total STO HTK*.05 will be total environmental impact on the planet.

If you want to deal with STOs by orbital bombardment with the minimum amount of civilian casualties, the "secret" is to use lower-power weapons rather than the biggest guns you have. This may seem counterintuitive so some explanation is needed:

Per the wiki page on Ground Combat,

The damage in ground combat for an energy weapon is equal to 20x the square root of its point blank damage in ship-to-ship combat. Armour penetration is equal to half the damage. Fractions are retained.

Weapon effect against ground units is calculated by ATK= 20 * sqrt(damage) and AP = 10 * sqrt(damage) or half the ATK, where 'damage' is the point-blank damage of the weapon. This has two implications: (1) we can calculate the effect of the weapon against the expected ground forces, and (2) damage done to ground units is not affected by damage falloff at longer ranges. Furthermore,

Orbital bombardment ships have the same chance to hit as ground units,

we also know that the to-hit chance against ground targets is not affected by range. Thus we prefer a longer-ranged weapon to minimize the damage taken from STO fire (from both loss of accuracy and damage falloff at long range).

Let's consider a "typical" NPR STO unit, which uses the Static base class and has the minimal armor level. Perhaps the most common early-game opponents will have a racial armor tech level of 12, so the STO in question will have 36 HP and 12 armor. Let us consider firing at this STO unit with railguns of varying calibers, and that the STO has a fortification level of 3 with no terrain modifiers (chance to hit is thus 1/15 or 6.67% per shot):

• 10cm railguns (1 damage per shot): ATK = 20, AP = 10 -- kill probability on a hit is (20/36)^2 * (10/12)^2 = 21.4% -- expect 70 0.56 collateral damage per kill (see formula below).
• 12cm railguns (2 damage per shot): ATK = 28.3, AP = 14.1 -- kill probability on a hit is (28.3/36)^2 * 1.0 (overmatch) = 61.7% -- expect 49 0.55 damage per kill.
• 15cm railguns (3 damage per shot): ATK = 34.6, AP = 17.3 -- kill probability on a hit is (34.6/36)^2 * 1.0 (overmatch) = 92.6% -- expect 49 0.67 damage per kill.
• 20cm railguns (4 damage per shot): ATK = 40, AP = 20 -- complete overmatch, 100% kill probability on a hit -- expect 60 0.96 damage per kill.
• 25cm railguns (5 damage per shot): complete overmatch -- expect 75 1.34 damage per kill.
• 30cm railguns (6 damage per shot): complete overmatch -- expect 90 1.76 damage per kill.

And so on. Once you have complete overmatch of the enemy STO (or at least what you think the enemy STO stats look like), using a higher-damage weapon only increases the collateral damage done. Once you overmatch one stat (usually armor as here, but would be HP if the STOs were armored), there's no benefit to increasing weapon damage*, and once you overmatch both stats then all you're doing is pumping up the collateral damage needlessly.

*Technical aside: The reason why is this: as long as both ATK and AP remain below the HP and armor of the target, respectively, increasing damage causes the kill probability to increase with the square of damage. Once you overmatch one stat, kill probability only increases linearly with damage. This means, in the example above, that a 2-damage or 3-damage weapon both have equal kill probabilities, however a 3-damage weapon is usually larger and more expensive, so the 2-damage weapon would be preferable.

EDIT: Furthermore,

Collateral damage is not linear with ground combat damage. The effect on the population increases exponentially for ground combat weapons with higher damage. The damage value of each weapon that fires is cubed, then the total damage is divided by one million.

therefore, collateral damage increases with the 3/2 power of the weapon damage. I've edited the calculations above to reflect this.

Given this, what weapon types are preferable for combating STOs? I've used railguns in this example for their damage scaling of +1 per caliber, but in practice low-damage railguns tend to be rather short-range and thus ships with railguns are vulnerable to taking a lot of damage from the STOs (they're fine for taking out Gauss turrets though). This also tends to be the case for low-damage lasers. Perhaps unexpectedly, the best weapon choice for taking out STOs is thus low-damage particle beams, since particle beam range and damage are completely independent and you can have a 2/3-damage particle beam with 200,000 or 240,000 km range at a fairly low tech level. Of course, since low-damage particle beams are not exactly a typical choice of main weapon, this implies that you want to build highly specialized anti-STO ships to do the job. Low-damage missiles are another option, but probably significantly more expensive and vulnerable to being taken out by STO Gauss turrets unless you fire sufficiently large salvos - I also think missile collateral damage is rather worse than beam weapon collateral damage, so I would recommend avoiding missile bombardment in the case where you want to recover the planet more or less intact.

EDIT: On the basis of the above edit, another weapon type which is very well-suited for the job is the much-maligned Meson Cannon, which always does 1 damage but can have a very long range once you develop the tech line sufficiently. Meson cannons are particularly attractive here since they are also, in principle, viable as a main beam weapon - mesons bypass shields, might not be as bad against unshielded opponents as we used to think, and apparently improve ground unit attack (I think this is a recent change in 2.0 or later).

Side note: one consequence of the mechanics here is that armoring STOs can be effective in a niche application: increasing the amount of collateral damage an opponent must deal to defeat the STOs. If we use heavy STO armor, which multiplies the racial armor by a factor of 3 instead of 1, the collateral damage incurred will increase by at least a factor of 3 against weapons which do not achieve total overmatch against minimal armor, but increases by even more if the opponent does not have overmatch, potentially increasing the total collateral damage by a factor of up to 9 if the opponent is using very low-damage weapons which do not even overmatch a minimal-armor STO. This is indeed a very niche application, but if you expect an opponent to take a planet and you don't expect to get it back, this can be a way to make the planet even less useful for your enemy.

EDIT 2: Corrected the numbers in the examples again, I think they should be correct against the collateral damage mechanics in the wiki now. I recall there was at some point an 80% reduction to collateral damage as well, which I have not factored in since I don't know if it affects naval weapons - in any case, the ratios remain the same.

And in terms of your problem, luckily I had much diffrent experience with bombardments. Last war that I had was with a per civilization. I bombarded theirs homeworld which was full of STOs. I destroyed them all with minimal losses on my part. (Even with shields, their firepower was enormous) It drooped the temp by less than 15 C. So in my games the collateral damage is way smaller than in your example. Either you attacked with way too much of a firepower, the planet was exceptionally small (If that is a factor in dust creation, not sure) Or you were at Endgame level tech and thus the damage needed was few times larger than in my case.

Not endgame tech ,. most of the weapons were 10cm, 20cm railguns and 25cm Plasma cannonades.  I performed a similar bombardment against spoiler STO's and knocked the temperature down 30 degree's.  Not sure its possible to link the dust to each weapon strike, the Plasma cannon do big damage strikes and there were lots of small railgun strikes , but at 95% of shots miss the targets I don't see a way to keep the bombardment small. But you did get less of a drop than I did against what would have been at least as many targets. I did ceasefire as soon as the STO were destroyed.

You are missing the point a bit. Destroying the STO batterries is not the problem I asked about. I asked about conducting a succesful planatery invasion.
I do not consider it a success if I genocide the population as part of the attack, I attacked a minor NPR yesterday, my fleet took nothing but shield damage however once all the STO were destroyed the planatery temperature had plummetted by about 50 degrees, if they had been a larger population with prportionatly more guns it would have been much worse.  The population is dieing at a rate of 30% per year.
If I had launched an assault without killing all the STO first then I would probably have lost too many troop ships to ennable me to land enough troops to win. It occures to me I should have saved before the battles and tried with and without a bombardment, but in this case my troopships are not well armoured so it would not be representative of someone building for an assault against STO . Also this race had rubbish STO (15cm Railguns and ROF 3 Gauss, rather than nasty plasma cannonades and powerful lasers)

My answer was more to the person claiming that STOs are OP, as the shield tactic was described by you an answer above. I just wanted to put my spin to it. By bad for not quoting.

And in terms of your problem, luckily I had much diffrent experience with bombardments. Last war that I had was with a per civilization. I bombarded theirs homeworld which was full of STOs. I destroyed them all with minimal losses on my part. (Even with shields, their firepower was enormous) It drooped the temp by less than 15 C. So in my games the collateral damage is way smaller than in your example. Either you attacked with way too much of a firepower, the planet was exceptionally small (If that is a factor in dust creation, not sure) Or you were at Endgame level tech and thus the damage needed was few times larger than in my case.

And In terms of collateral damage itself. I do not see a realistic scenario where you can take over a planet that is well defended without some unintended loses. Either on your part, or enemy's. It is similar to a situation when you try to conquer a city. Either you level it to the ground, thous saving your own soldiers or commit to CQC, which will leave much more of the city intact, but will be very costly for the attacker

I do not think that STOs are OP. The way you deal with them is simple. Well shielded Beam warships. You just move into range, exchange fire, and when shields are starting to break you retreat this particular ship. Other methods described above are fine too, but this one is most practical in my opinion. As Those beam ships can be your regular warships that are designed to also multitask in sieges. No need to design a new armored and expensive transport. It will also minimize the dmg to the planet itself.

Altho, it is important to take into account the tech difference. Conducting assaults on civilizations that outtech you are and should be tough and resource intensive.