Core Detonation: who uses it?

Core Detonation: Never
Gas Warfare: Never
Information Warfare: Often
Mass Drivers: Only to cull population, never to take planets.
Mini-Soldiers: Semi-often, less so in TA as it's more difficult to come by.
Tidal Disruption: Very often to very seldom, depending on the playstyle for the game and how fast I can build up the planets I take.
Traditional Warfare: The rest of the time-fairly often.  I prefer information warfare, though, and typically have the no mercy invasion center built before my second invasion.

Agreed. I find though, with Mass Drivers, that you have to be careful when your soldiering gets up there.  You can accidentally take a 10B planet with 1000 troops when you meant to cull population. Sometimes at this stage I'll shift to Info, Gas, or Mini for the tenderizing phase.

This is why you mass with 1 troop. 

There's an interesting bug that to my knowledge never got fixed where mass drivers considers the base quality of the planet when doing the damage, so if you mass a class 5-8, you can actually wind up with more tiles afterwards.

Jah, 1B troops, I know.

You mean, a class 4 is potentially 16 with Soil Enhancement, Habitat Improvement, and Terraforming, so the AI calculates the Mass Drivers against the 16, decreases it say, by 50%, but then in effect upgrades the remaining tiles?

No, 1M troops.

No, I mean, the class 5 is a class 8 with soil enhancement, habitat improvement, and terraforming.  The game calculates it if memory serves as a class 5 for damage purposes, so if you damage it down to a class 4 base, you wind up with a 13-16 PQ planet.

It's been a while since I tried this, though.

Oooh, and if you've selected Neutral and researched the Planetary Improvement techs, then the planet comes out ready-to-go 16 PQ?

I pretty much only use mini-soldiers. Almost never get an improvement lost and I never have trouble taking the planet with one transport with 3000 soldiers. I don't see why traditional would be used instead except for the 500bc price tag. Is that why?

I also use Information warfare when the planet is a good target for it. Rule-of-thumb for me is around 50% morale. A large population combined with a very low morale can leave you with more population than you had on your transports.

I may have used Tidal a couple of times, especially if the AI planet is under-developed anyway.

Interesting. You're saying this is better than two transports of 1000, first Mass Drivers than Traditional or Gas.  I guess the logic is that you only need to build one transport, you only risk a small number of improvements, and you have a good chance, with 3000, of starting the new planet off with a higher base population than with 2000.  On the other hand, you need Advance Troop Mod for the 3000, and Mini-Soldiers, which you don't have for your first invasions.  Your right about Tidal.  I should use it more for those planets.

If this occurs, is it true you get to keep the transports?

You may be right that doing it that way could save you soldiers and some cash (200 bc maybe). I have never tried to compare.  If I invade an AI planet of 6 billion people with my 3 billion, using mini-soldiers, I typically wind up with something like 1.5 billion to 2 billion (sometimes much less though). At a cost of 500 bc. Of course assuming that you don't have the No Mercy Invasion Center. I don't know what would typically be had by using mass drivers and then traditional. Has anyone done both?

Basically I don't have the patience to send 2- 1000 million transports to a planet. I don't think the build time for a transport with 3000 capacity is that much longer than those with lower capacities. Most of my later game planets will build one in 2 turns. So if i can get these ships built at the same rate, but only need to manage half the number I personally will go with one trasport with mini-soldiers. The down side I guess is that I have a single planet losing 3 billion people at once, instead of 2 planets losing 1 billion. But to me thats a plus, once a planet gets to its maximum population (usually 13 billion) i send 3 billion away, then i don't have to worry about that planet's population for a while.

While its true that you don't usually have mini-soldiers for the first invasions. I try to get it ASAP once the first war starts. So there won't be many invasions that i can't use them. And at the time in that game. many of the AI planets that will be invaded will have less that full populations anyway. So 1000 million troops may take the planet with traditional warfare alone anyway.

*edit* Quote related format mishap. Reposted.

Information Warfare is my usual, then Mini Soldiers if I can get it (doesn't appear in Thalan tree), then traditional. Very rarely is Tidal disrupters worth using; it depends on the soldiering stat of the target (high stat on target civ get tidal, lower stat get mini or mass driver).

Information Warfare is my usual, then Mini Soldiers if I can get it (doesn't appear in Thalan tree), then traditional. Very rarely is Tidal disrupters worth using; it depends on the soldiering stat of the target (high stat on target civ get tidal, lower stat get mini or mass driver).

The beauty of IW is that it is more effective against larger populations. Spy all of their morale buildings, get their morale down as low as possible, then hit them with a 1b transport. Very rarely will anything with more than 10b people survive. The hardest planets to take are between 6 and 8b - you just can't get the morale low enough for IW, and traditional isn't quite enough. Those usually require a second transport.

Taking a planet will always use up at least one transport. Invading sequentially (one transport loses, send in another) will always result in losing every transport used. Attacking in a fleet (send 6 transports in at once) will result in transports surviving only if their their entire troop load survived the battle. If you win with 5+ billion people on the planet, 5 transports will survive - the sixth is always lost. If 4.99b people survive, you'll only have 4 transports left.

I haven't tested this since DL, as sequential invasion is usually better. Perhaps it's time to revisit this to check it out again.

Good stuff. 

But in the case where you use IW and you "end up with more people than you started with", then you don't lose any transports, right?  That is, 2B join your side and only 1B die in battle.

You can trade with the Torians or Iconians for their race-specific techs prior to invasion, and then keep the improvements. 

I'm curious why nobody likes the Gas Warfare.  I use it all the time.  (But then I use it all the time in real life, also.)

(And that's 4 people who have never used Core Detonation).

A lot of the Iconian techs aren't tradeable, and the Torians are the guys who colonize a jillion planets and then never build any improvements on half of them.....at least in my games.

Nope, you always lose at least one transport. I've seen a one billion transport win an invasion with 3b+ people left, and still you lose the transport.

Oh, and yes, you still lose the transport when using information warfare and you have more colonists than you started out the battle with. The reason why is that the transport is used to build the initial colony tile. SO you  ALWAYS lose the transport...it gets transformed into your colony main city.

No Mercy.

But on a more serious note, it's not worth the 200BC every time.

You're right, I just tested this.  You don't get to keep the Precursor Library and Archive and you can't trade for Precursor Studies.  Feh. 

Here's another question for y'all:  There seem to be two kinds of "race specific" techs: those that are "race specific" that you can trade, and those you can't.  I gather that the starred items in the trade screen are the former.  Correct?

Judging from Galactaopedia, there also seems to be a third category: Those you can't trade for but that you can steal.  They make a distinction between "untradeable" and "unstealable".

I end up trading for every tech I can to help limit the losses. I will likely never USE all those buildings, but they give a big leg up on building your own. I hate losing buildings if it's avoidable, and I wish they had distinguished between buildings you don't have the tech for and buildings you CAN have the tech for, but you haven't researched yet. It's rather frustrating to lose several planets full of stock markets because the planets flipped the week before you finished researching them

Correct. For that matter you could mod the tech tree to include techs that are NOT race specific that are untradable.

They are set as two separate conditions on the tech. Likewise, you could make a tech that is tradable but not stealable. I don't think there are any in the current tech trees, but I didn't know there was any untradable but stealable ones, either.

Awesome answers, guys. 

Spore Weapons can't be traded or stolen, but Germ Warfare (the prerequisite for Spore Weapons) can be stolen.

I've never actually tried to steal it off of someone who had that SA, but it's possible.

Looking through the XML, Counter Espionage can't be traded, but can be stolen.  I don't see any others, apart from Germ Warfare.

Even if you steal Germ Warfare, can you still research Spore Weapons?

Come to think of it, probably not, since TA's tech trees are race-defined.

But it would seem to be workable in DA, at least.

Nope, sure can't. Stealing or trading a tech not on your tree doesn't give you the ability to research starting from it.