Planetary invasion

Avoid using the techs that reduce planet quality, unless you KNOW you're going to lose. If you're invading a 20b planet with 1b troops, use mass drivers to maximize the casualties - the planet won't lose PQ unless you win the invasion.

If you have higher soldiering than your opponent, use minisoldiers if available. It improves the advantage you already have, and does minimal damage.

If the enemy has higher soldiering than you, use tidal disruptors. Yes, you will lose much of what's on the planet, but it cuts their advantage over you more than minisoldiers boosts your advantage. Absolutely devastating against Dread Lords (not that you really need it, but whatever).

If the enemy has low morale, (or can be made to have low morale with spies in DA/TA) use information warfare. It's pretty easy to end an invasion with more troops than you had on your transport. It is expensive, but you'll make much of that up by not losing buildings to tidal disruptors and not having a really low population planet.

Using active spying on some buildings does give a supplemental edge too. It's crazy to realize how many unhappy people could join you invading forces if their Morale has dropped exponentially for a few turns.

The pre-Invasion screen does have percentages listing before you select which tactics as explained by Willy above.

Soldiering ability also plays a key role in both sides of the equation.

Thanks guys I'll take this into account in my next invasion!!!

This method may no longer work in TA but the classic method uses a two stage process. The intent is to be a stingy as possible with your own invading troops. Every troop you lose in an invasion is population that you don't get back once the invasion is over.

Basically to minimize your own population loss you do an invasion that you *know* will lose but uses a particularly destructive invasion tactic that happens to also be particularly effective at reducing the planets population. Mostly I used Mass Drivers. I would take 1000 or 2000 troops against a pop of 10B using Mass Drivers and that would comfortably reduce the defending pop down to a more managable level and since the first attack lost there would be no damage to the planet. I would then attack the reduced population with another 1000 troops but this time use a less destructive tactic like mini soldiers. The end effect is that you can take the planet for 2000 or 3000 troops instead of wasting close to 5000 to 6000 with little or no possibility of damage to the planet.

That still works in TA. Just be careful if you have an extremely high soldiering stat - I have ruined planets because I won at 12 to 1 odds, even 14-16 to 1. Don't try this if the odds are less than 10 to 1, unless you are badly out-teched.

I've been giving fleeted transports another try, and they are quite effective in some circumstances. You always lose at least one transport (just like attacking singly) but any transports you can fill with the surviving troops, you keep. (attack with 9 1b transports and live with 7.9b troops, you would keep 7 transports; win with 12+b troops, you would have 8, not 9). This is most effective with info warfare and mini soldiers (or tidal disruptors if you don't have the tech to use their buildings). Only use it when you have a pretty big advantage though - close battles are still better off using sequential invasions.

In TA, I like tidal disruptors alot if invading a planet that has a lot of improvements I can't use anyway (like playing as Terran and attacking the Drengin).  Since all those improvements will be lost anyway, why not wipe them out invading  and get the bonus?  Of course, if I'm invading a planet with similar improvements (like Terran against Krynn), this is less helpful.

I for one like to use a somewhat more advanced tactic.

apparently if you have a lot of troops your enemy's advantage suffers. SO I create a massive fleet of troop carriers and bum rush a planet with them.

we're talk 16000 or so troops versus 8000 here, for some reason I've seen the enemies advantage halve.

Maybe I'm just being a newb and seeing a number comparison gauge that I normally don't see because blackr ace colour, on blace race background is a bad idea?

I usually take 2K troops and invade 16b pop. With my bonus and Tidal destruction I usually win. Of course I loose on teh quality but since I never count on those planets helping me anyway whatever is left is a bonus for me.

I'm kind of a purist My planets are the good stuff conquered ones are for slaves!

Are you saying you attack with 16000 troops or 8000 listed?

Either way, halving advantage or not, that just isn't viable as part of a larger campaign. You'd be tooling around for hundreds of turns before taking out a single enemy capable of putting up a fight.