| Antareans |
The Antareans play a peripheral role in this game, though they can be annoying if you are playing strategic combat, or if you picked a bad race. Their ships are rather well-equipped defensively, and require some expenditure of resources to eliminate, especially if they visit early. If they arrive later, they are relatively easy to defeat despite the increased size of the fleet, and if your game lasts long enough, your technology level will be so high that defeating their homeworld is a trivial task.
The Antarean ships have relatively high beam defense and missile evasion, but the missile evasion is low enough that ECCM missiles will do some damage. Once you have MIRV nukes and the ability to produce an emergency fleet, Antarean raids are no longer an immediate threat to your survival. The efficiency of missiles is further enhanced by emissions guidance system, since Antareans don't use shields: a handful of EMG missiles fired from behind will annihilate even a titan.
Homeworld strategy:
An attack on the Antarean homeworld should be attempted only if you have relatively advanced technology. If you don't have Orion technology, you can either use extreme force in the form of several well-armed, heavily armored doom stars or titans, or you can use the cheap but elegant method.
The minimal Antarean fleet is a single frigate equipped with battle pods, time-warp facilitator, phasing cloak, and a plasma web (one may notice it requires a few levels of hyper-advanced technology). With this ship, you do not have to worry about withstanding their attacks. You need only remember to wait before firing, recloak on even-numbered turns, and time the deaths of the star fortress and ships to roughly coincide so you don't run out of battle time. This requires some non-trivial number crunching and is not guaranteed to work - the largest fleet I have been able to kill with one frigate had a battleship and two cruisers in addition to the usual star fortress and titan. If you don't want to bother with damage calculations, you can use a cruiser with a black hole generator, and employ it in the same manner as the frigate. If you don't want to stoop to using a time-warp facilitator (or you have trouble counting even and odd turns) you can place a black hole generator, several stasis fields, and a phasing cloak on a battleship, and that will also work.
If you are lucky with Orion technology (in particular, damper field), you can eliminate the Antareans shortly after killing the Guardian. The only other technology you need is Dimensional Portal (either from the special leader, or stealing it from an opponent) and Automated Repair Unit. Then if you attack with a few battleships carrying EMG missiles, heavy mount beams, battle scanner, damper field, and reinforced hull, you can strike their ships with missiles and erode the the star fortress' armor and structure from afar with the beams. You should be able to regenerate whatever damage the Hv particle beams do to your ships with Automated Repair.
The last, and apparently most often-used strategy, is to use high-level weapons to squash the fleet in head-on combat. The stellar converter makes a safe weapon choice, since the Antareans' reflection field is completely ineffective against it. However, it is not cost-effective in any context, except for bombardment of shielded planets. Disruptors, death rays, and maulers are sufficiently powerful to punch through the field with a decent probability, so your fleet sustains minimal damage. Gauss cannon, plasma cannon, and particle beam may carry the possibility of self-inflicted losses, although the high-energy focus system and the heavy-mount option help.
Capturing attackers:
You have a good chance of plundering technology from a captured vessel if it contains a weapon or system you don't have and you scrap it over one of your starbases. This can yield exceptional returns in the case of Antarean ships, since they carry technology which is both valuable and impossible to research conventionally. However, Antarean ships are fiendishly hard to capture, as the crews have high combat bonuses and the ships are equipped with quantum detonators, which give them a 50% chance of self-destructing when their marines are overwhelmed. The combat bonus is doubly unfortunate since effective custom races often take a ground combat disadvantage. For those really intent on capturing these ships, it is best to have some of the following race attributes:
and some of the following technologies:
Together, these give you a ground combat rating of +90 without the armor and marine experience factored in, and with them you have a maximum rating of +140 (not including mercenary leader bonuses) and 3 hits to kill, making even the Antarean star fortress a reasonably easy capture. I am unsure of the asymptotic benefit provided by an extra hit, but it seems to be equivalent to at least +10.
Obviously, the utility of capturing Antarean ships is maximized if you capture them early in the game, so you want to minimize the technology and building time for a capture fleet. To capture the ships, you have to board them, and to do this, you have three choices: transporters, immobilization, and assault shuttles. Transporters are not very cost-effective, as the damper field will whack about half the marines as they come in, and the technology comes relatively late in the game. Immobilizing is done most reliably with multiple tractor beams, as trying to disable the engines with weapon fire is never certain. Unfortunately, the battle AI tends to self-destruct immobile ships, so if you cannot finish the job in one combat turn, you need a stasis field, which also comes late in the game. Finally, assault shuttles work well because of the overwhelming numbers of attacking marines possible and the low technology needed. Even though shuttles do not benefit from experience, the difference in effectiveness is not so great, as the antareans don't give enough notice before attacking for you to build an elite capture fleet. In my experience, every 10-point difference in combat rating will give roughly a factor-of-two difference in death. Thus, if your troops have a +50 rating and you're hoping to capture a destroyer with +110 defenders, you will have to outnumber their 8 marines by a factor of about 64, meaning you will have to release 128 sets of assault shuttles. A battleship would require 320 while a frigate would require only 64. Since you can plunder pretty much the same technology from every size ship, you should target the smallest ship and finish off the large ones by more conventional means.
Extra info:
If you are telepathic, you can use the captured ships one combat turn after they are captured, but you can only gain permanent use if you win the battle. Thus, even though the homeworld titan gets replaced every turn, you cannot use that fact to your advantage.