Basically, it isn't worth it. The defenders can shoot back and we are talking a whole world of them and to deploy anything but a huge transport to attack a world is suicidal. Transports use the kind of stuff you are talking about while attacking, that's why the attackers get an advantage.

Cross posted from the "ethnicity" thread:

Y'know, it is funny... we can chuck asteroids at a planet in GC2, we can wipe out EVERY LIVING (sentient) THING on a planet by invading it in GC2, but we can't attack a planet from orbit with the intent to do less harm. Hmm...

Actually, modern predictions state that the U.S. could fight and successfully defend a large-scale invasion from space with conventional nuclear ICBMs; no matter the source.

Sure, assuming they didn't hit all our missiles first. And, before you balk, we could probably have made a pretty big dent in the Soviet arsenal with a first strike. Of course, nukes won't really help you if they a) have shields that beat nukes or have point defense that can shoot down missiles. We have at least a working theory of how to do "b" right now. And they don't have to defeat every nuke, just force us to use too many nukes in the lower atmosphere over the US... there's not much point in repelling an invasion if you makes your country uninhabitable!

Smaller ships, like troop transports, stand an infinitely better chance at survival to touchdown, and planetary batteries are nominally useless against ground forces.

Smaller ships?!?!?! I'm not sure I follow your reasoning. A standard troop transport in the game is a "CARGO" hull, the second-to-largest size available. One "TROOPS" module carries 500 "legions," which drops your planet's population by 500 milion, if I am not mistaken. A ship attacking from space has all its defences up and running, and has the option to go away if the planet gets too hot, a transport has to keep coming in. Depending on how the atmospheric entry is accomplished, the transport may be blinded for a brief period, and/ or have limited maneuver.

Anyway, who has a better chance of survival, an unshielded troop transport, or an armored, shielded, defended warship? UPSHOT: you have to take out the defenses before landing troops anyway, so I just can't agree with your points.

Guided missiles intended to shoot down warships would be not only big but numerous, [...] Expensive, likely, but faster, with lower mass, and hitting power to spare.

Your summary is a good start, here's a better one:

DEFENSE:
Advantages: lots of room to put weapons and sensors, mobile (or successfully hidden) weapons are probably harder to detect on a planetary surface, homeground advantage in terms of precise astrogation and understanding of local solar "weather."

Disadvantages: everything you fire from the ground has to get up through a deep gravity well (thus giving the enemy time to react), everything you keep in space is probably much easier to target than stuff on the ground, the targets you are defending are too large to hide.

OFFENSE:
Advantages: You have the HIGH GROUND and MANEUVER! The defender is fixed in one area of space... you can stand off and dodge his long-range fire, take potshots at his targets, and engage point-defenses as he uses them to shoot down your missiles, or send in much smaller ships (fighters) that can take the fight much closer to the enemy. You also have a darn good view of the battle, especially for fine-tuning your aim! Even if those targets are hard to hit for the first few days, after a while even the most incompetent crew will figure out that it will be in the exact same place a day from now.

Disadvantages: if the enemy gets lucky, you don't have anywhere to run, and you are limited by resources... once you run out of fuel, ammunition, food, etc., you have to break off. Of course, you CAN come back...

Edit: And that's not even considering the planet's rotation. You'd likely want to be geo-synchronous to your target(s), but that too, would take time. Time is not on your side in any attacking action. And nevermind accquiring a firing solution, you also have damage control to take into account.

Sorry, I just don't buy it. I've had enough physics to know that this is a complex problem, but one that we could solve NOW, given the proper information (which would be available on any planet your freighters had ever visited). Not only can we accomplish the feats noted in the original post, we can hit tiny celestial bodies millions of miles away with minimal course correction. Here we are talking about punching UTM coordinates into a computer and shooting bearings off the planet and a few key local astronomical features.

Of course, you could still just grab an asteroid and drop it on the best-defended continent, and then slowly pick off the remaining industrial targets while the defenders wring the salt water out of their socks!

[...] in a bombardment situation it would still take time to get into position, and the enemy knows you're coming from lightyears away. Anyone sane would utilize planetary batteries in such ludicrous numbers as to bathe you in a deluge of fire; remember Starship Troopers? [...] Given the complexity of it all, even a second is an eternity. The computer's calculations are nothing; but getting into position is the thing.

I still don't buy it. I'm not really sure there is any "position" to speak of... orbiting a defended planet is probably not the best strategy: you are more likely to maneuver nearby, staying as far out of the gravity well as possible, making what would essentially be "strafing runs." We don't have any real idea of the physical scale of weapons range in GC2, but but all you have to do is put your ships close enough that they can maintain a barrage weapons fire for long enough to draw out defensive fire and engage the defenders. A couple hours to days of this should be enough. Remember that the defenders aren't GOING anywhere.

Also, remember that any "deluge of fire" will also be there to meet your unarmed, unshielded, very large, probably slow, vulnerable transports. Again, if there are defenses sufficient to prevent bombardment, they MUST be eliminated before a landing can take place.

FYI: there is a strong precedent for this in science fiction as well as modern warfare. That doesn't mean you HAVE to do it this way, Sci Fi "standards" are broken all the time (fighters with hyperdrives in Star Wars, EarthForce never takes the spin off the ship before going into battle in Babylon 5, FTL combat in Star Trek). However, this is SCIENCE fiction, and it is much less satisfying if something is declared impossible for reasons which are not consistent with the rest of the "universe."

Eh, fair enough I suppose. To me, "orbital bombardment" is a generic catchall for in-system space-to-planetary surface attacks. It is particularly insulting when the enemy has sufficient space supremacy to simply park their ships in orbit and rain death on you.

I specifically avoided using "orbital bombardment" in my original post, because the game designers are obviously sensitive to the idea of wiping out planetary populations just to be a bastard. I don't mind that sensitivity at all, but I want options for denying my opponent the use of his planet as a military and economic resource, at least temporarily.

On the other hand, regarding the troop transports, I always imagined the troop modules disconnect from the ship and enter the atmosphere independantly.

Yeah, they certainly look like they should, huh? On the other hand, if the ship doesn't land, it is awfully hard to rationalize why it disappears when you are done. I just assume that the ship lands in a very "aggressive" way, and provides physical cover while the troops unload.

No, it didn't. But we were on what I perceive to be different topics entirely, so my comments were misleading.

No hard feelings here at all, man.

Where the heck is this feature at? Chucking asteroids? Are we playing the same game?

It is one of the "invasion tactics":

Mass Drivers Description: By attaching drive-thrusters to nearby asteroids, we'll be able to use the space boulders as large-scale projectile weapons. While the attack will be almost unstoppable, destruction on a planet-wide level is inevitable.

forget about all the missles and point defenses for a second, what about beam weapons? this should be as close to point and shoot as it gets, no need to calculate trajectories of missles and whatever, just consider the bending of the beam due to entering the atmosphere (think of a straw in a glass of water), and since everything would be turret mounted, you could attack from orbit and not need to worry about a perfect firing position

There IS also degradation of the beam from passing through atmosphere.

Basically, there are no TECHNICAL reasons why you cannot attack the infrastructure of a world from space. The game designers don't want you to, apparently because they associate this with the (rather nasty) practice of bombing planets to kill off the population, as featured in Masters of Orion and its sequels. Apparently they are too tired of the topic to entertain other possibilities. Oh well. It's still a spiffy game.

Oh yes ya know there's so much moral difference between commiting genoside from orbit without your guys getting hurt, and commiting genoside up close and personal WITH your guys getting killed.

In all fairness, there is a difference: if you are invading, you are actually fighting FOR something, and giving your opponent the chance to fight back.

On the other hand, there is also a tangible difference between committing genocide from orbit and destroying key economic and military targets to prevent them being used to support your opponents war effort. THAT difference formed the basis for this thread.

All in all, I like the idea of being able to achieve true space superiority. But it's kind of low on my priority list. There would probably be a lot of effort to implement it, both design-wise as coding-wise.

Actuall, it is already implemented, as "invasion tactics." An intial step might be to simply allow these generally. The AI would have to be tweaked, that's all. On the other hand, a system whereby you could actually AIM, and try to take out valid military targets, WOULD require some programing.

Personally, my biggest objection is that the ban on attacking planets seems inconsistent and contrived. You CAN do it, but only if you plan to invade, and it only works if you succeed. The reason you can't just attack a planet without invading is that the developers don't like it. I don't really blame them, bombing someone from orbit just to kill them off is emphatically not cool (and bad karma). Of course, if you go in and wipe out a planetary population from the ground, that is accepted But it doesn't make sense in game terms: does God just reach down and erase the damage if your invasion fails? I haven't heard a reasonable, consistent "game" reason why you can't attack a planet from space, certainly no argument that justifies the way it works in the game.

In fact, if you look through the serious "hard" sci-fi literature, or just do the math, you find that bombing a planet is preferrable to invasion. It doesn't take a military genius to see that GC2 (and every other 4X game I've seen) takes liberties with ground combat. Take the recent war in Iraq: one side put 300,000 troops into battle to invade a country of 26 milion (a roughly 1% troop-to-target ratio) constituting around 0.3% of the planet's land area. By many accounts, this was not enough troops. So, several billion is probably what you'd need, and that's what you have in GC2.

But it isn't enough to have the troops. The Iraq effort has also required extreme, sustained logistical operations, including the shipping of tremendous amounts of food, fuel, ammunition, and other products. At least both sides are the same species, meaning that, in the event of an unfortunate logistics issue, the troops COULD find food, shelter, medicine, etc. for a little while. Imagine what happens when your billion-man army discovers they don't have enough sidearms to go around, and the enemy's laser-harnesses won't fit on their heads?

Then there is getting there: a US helicopter carrier (arguably the best model for a troop-transport spaceship) carries about 2,000 combat troops. The largest, most modern military on the planet needs MONTHs to move 300,000 troops, some of whom were already in place! Landing BILLIONS of troops into a combat situation would certainly require more than one ship... probably thousands. Unless you can shrink your troops down to little dodecahedrons for the trip.

Then, of course, you have the possibility of taking BILLIONS of casualties. Yeah, billions. So, if it were me, I'd consider doing things like, oh, bombing their factories and telling them to stop sending people to kill my people. Maybe that's just me.

For me, like many others who play GC2, the fun of the game is the story it tells. When that story doesn't make sense, it loses some of the fun. However, like you, I have other priorities... there are other things which cause more interference with my fun.

Oh yes ya know there's so much moral difference between commiting genoside from orbit without your guys getting hurt, and commiting genoside up close and personal WITH your guys getting killed. In all fairness, there is a difference: if you are invading, you are actually fighting FOR something, and giving your opponent the chance to fight back.

And don't forget than to invade planet you need transports and that at least one transport will be used if the invasion is successfull. So you need to assemble an important transport fleet over a long time in order to be able to get all planets belonging to another race. I guess that the time will be less important to get an operationnal death fleet if killing from space was allowed and no ship disappears when doing the Orbital Bombardement.