Gaian Crescent

The AI is attacking in force before you even have your second planet?  You playing against unfair or something, because typically in my experience the AI might send a few harassing cobalts but otherwise goes straight for those three terran planets.  I'd recommend starting with a Marza if you're TEC; I don't think Akkan cuts it here.  Evacuator and Mothership for Vasari and Advent should go without saying.

Your first goal on gaian crescent (or any map) is to immediatley take your nearby asteroid.  Build a capital ship and send it over right away.  You should now make preparations to take the desert planet.  The trick here is that because of the map layout you don't want to invest too much money in your army.  If you're TEC, you can take out the defenders with just a Marza.  If you're Advent, purchase the second level of your mothership to get shield restore (always pick colonization first) and then you should be able to do it with only a few disciples.  If you're Vasari, just get assailants since they'll be useful late game (but not too many).

You should be moving without stopping.  Build your capital ship, take the asteroid immediately, then go straight towards the desert planet.  Research repair bays while you're attacking the desert planet, and focus on killing the siege frigates first.  Once the siege frigates are dead, use either your capital ship (if Advent or Vasari) to colonize the planet or quickly run a colony frigate in to take it over as TEC.  While killing the remaining defenders, build a repair bay to bring your capital ship back to full health.  Also build the labs necessary to research volcanic colonization, then immediately jump to the next planet to take it.  Repeat the process (and bring in a few units if you like) to take the remaining two planets.

You can easily have your four starting planets locked down with this fast and low-cost maneuver.  Now you want to start heading towards the terran planets and taking them out.  Start building your real army at this point, particularly long range frigates, and take the terran planets.  Because the AI produces lots of light frigates (and gets them killed...) to clear out those terran planets, your LRF-based fleet can mop it up nicely.  Move fast enough and you can have all three terran planets under your control.

From that point on, I find the best way to win is to build two separate fleets for each side of the AI's empire.  Use scouts to figure out where its fleet is, then attack them from the other direction.  As soon as they arrive on the other side, run away and send in your other fleet.  They'll spend all their time running back and forth while you kill their planets.  Quite hilarious actually.

I actually played a wonderful game against the AI on that map earlier this week. I got hung up on their volcanic planet because it had high security protocol and they built a huge number of repair bays and hanger defenses there.  Took me a while before I managed to break those defenders.  I used the trick I described above to do it; two fleets playing cat and mouse from either side of his empire.  Got a level 10 Marza and level 10 Kol out of it in the end, though, which is totally sweet

huh, not the question i was expecting. Darvin does a great job of laying out the basic strategy for this map (and its applicable to many others as well) so I won't elaborate on that end.

the question i was expecting was this one:

is it better to try and settle the Terran worlds and win with mid-game economic advantage or is it better to play the rush and go directly after your opponent's homeworld?

alot of the small maps are very obviously Rush maps but Gaian Crescent is one of the more interesting small maps because its so hard to tell whether its a rush map or a colonizing map. i've won with both approaches and i couldn't tell which way was better. anyone have an opinion on this matter?

Gaian Crescent strikes a wonderful balance between being a rush and colonization map, and both approaches are totally viable.  Without actually playing a bunch of games against players on that map (because I've only played AI's on the crescent) I couldn't say which approach is better, but I can definitely say both are playable.  I suspect because it's five jumps to the enemy homeworld that you'd probably want to be in more of a harassing position than a hard rushing position.  Erring too heavily on military units that early will just get you countered by someone who bides his time then researches the right unit to counter the ones your rushed with. 

I've tried Darvin's method but the problem I still have is with credits. I buy two planet devs to stop the credits leeching and then build the cap ship factory. I then build the extractors and move the free cap ship to the asteroid. Once the defenders are dead you have to wait.... and wait before colonizing to make sure you have enough credits to cover planet devs for the new "planet" to avoid further credit leeching. This method looks fine until about half-way, when I have the desert, ice and volcanic planets under my control but by then the opposition has a fleet ten times my size. I guess I'm doing something horribly wrong and would be most grateful for any further assistance.

It sounds like you are playing with an un-upgraded version!?  The original/out of the box game had errors on the Gaian Cresent map (no planet infrastructure)... that have since been changed. 

Upgrade your game to 1.15, and the above advice will apply... and your whole game experience will change.

Ah, 1.00 and all its little quirks.  I ran into the same problem on Gaian Crescent when I first played it.  Patch and the map goes from unplayable to brilliant.

You'll need to download impulse to get the update.

Thanks guys; I'll look for the patch and get back to you.

I should have mentioned:  watch out for your saves no longer working.  Each major upgrade has rendered the previous saves and replays inoperable, and its not always easy to go back to the previous patch (altho it should be easy to go back to 1.00).

Also, it came to my attention that, the original Gaian Cresent map also did not have the homeworld 'capitol' designated and paid for.  That is also a big reason for your difficulty in producing income, because there is bonus income and resources (4.0, .4, .4) for your designated homeworld.

Thanks guys, particularly Darvinn3 and SageWon. I upgraded to 1.15, my home planet works fine and with your help I conquered this map first time up. It's interesting to see that the black market is now part of the main screen and navigation feels a bit different but it's a vast improvement on version 1.0. Thanks again and I'm sure I'll be returning to this awesome forum again soon.

The map certainly got changed. It used to be you start without homeworld, I thought ti was meant as a challenge, but seems it was an oversight on their part.