I have read that the AI will practice a "scorched earth" tactic when fighting an invasion, destroying its own buildings so that you’re left with a less developed planet. Does anyone have information on when the AI does this?
I my current game (normal difficulty) I have had a war off and on with the Antarians for years. However, we’d signed a peace treaty and I’d spent at least a dozen turns adjusting my forces and generally getting ready to break the treaty. I moved a fleet of 5 fighters and a second fleet of 5 transports near the Antarian homeworld. While still at peace, I positioned my fighter fleet next to the planet and the transports were two parsecs out. My fighters had 4 movement points and there were 4 ships in orbit so I needed to destroy them all in the same turn, using 1 movement point for each attack. I moved my transports in. The first wave, three transports, was defeated; the second wave of two transports was successful. All this was on the same turn. Taking the planet I found 3 unused tiles and thought it was an unusual approach for a homeworld. Can the AI scrap buildings between the attacks of your turn or does it have to wait its turn? I hadn’t attacked that planet before, but it was on the border of my sphere of influence for a fair number of turns. I can’t figure out why those tiles would be empty if the planet hadn’t been threatened before and we were at peace until the attack.
This brings me to a possible AI exploit. If the AI will scrap its own improvements before you start an attack you could try the following: Roam its territory with a fleet of transports and fighters, park next to the planet, and as the AI perceives the invasion it scraps buildings. Sit there a turn, don’t invade, and then proceed to the next planet. In theory it could be possible to exploit the AI behavior into destroying its own economy.