Easy at first, death later in the campaign?

[mund]

So, I'm kind of confused.
I'm playing with a friend of mine against two dif 7 AIs, and for the first couple hours we do fine. It's easy, even. We've been playing on 30 planet maps for quicker games while we get used to it. Anyway, the problem is that once we hit about the third hour and we've both got about 5 planets each, the AI progress is around 250-300 and the AI gets so powerful that our progress is slowed to a crawl. We manage to previal and push a little further until we get simply annihilated by a massive build-up of ships that is quite nearly impossible to defend against at that stage even with multiple forts and exploiting the AI.
So, how are we failing? It really makes me more afraid to try a larger map, spending much more time just to lose in the same fashion. I can't really think of anything else to do besides make a mad rush for the AI's core station while leap-frogging most planets, taking maybe a maximum of three each. That doesn't sound very practical. Maybe we're just getting really unlucky on data centers? I'd assume it's not entirely random, but we've only ever seen two or three in the entirety of a 30 planet map, and I remember the tutorial scenario having six or so across the ten planets.

[eRe4s3r]

Well, that is the reason i am playing on DIF 5 now - i have no idea how to move foward at DIF 7 after 3+ hours (wait till its +5 hours)..

Ship numbers get insane

[Haagenti]

If you are at a reasonable AI level, the AI will amass *very* significant number of ships at planets that border on planets that have no AI Command Center (your planets and planets where you killed the enemy AI Command Center). This amassing will go on and on and on. Note that it also amasses ships on all other planets but very slowly.

What you are probably doing is fighting the AI at its own terms: you look for their best defended planets and fight them there. This becomes a slugfest, forcing you to replace casualties and costing time. In the mean time, other planets keep amassing units and your situation gets worse and worse: after you conquer a 1000 unit planet, the next one will have 1500 and so on.

What you should be doing is fighting the AI at your terms:
- your own planets, because there you can employ forcefields and turrets for an immense advantage.
- AI planets where the AI does not have 1000+ ships

So at start, speed is of the absolute essence: every planet that you cannot capture in a few hours will not be captured at all. You must establish a home base of about 6 planets (less than that and you won't fit all the energy you need on them) and that will be it for the rest of the game.

After that, split your forces in two:
- home defense force
- away force, which consists of most of my mobile fleet

Home defense has a single role. Defend as cheaply as possible. This means:
- don't use many mobile units, since they are in short supply
- don't suffer expensive casualties, since this takes resources to replace
- don't use too much energy, since this is also in short supply
For this reason, home defence must consist mainly (preferably completely) of forcefields and turrets.

The role of the away force is to:
a) get away from your defensive parameter to relatively undefended planets, where life is much easier
b) scour the galaxy for libraries, data centers and advanced factories
c) sustain itself with mobile builders who build factories to build units
d) keep moving: staying to long in one place attracts the amassing of units
and ultimately
e) destroy AI Core planets

A good example of the above may be found in the save game attached to http://arcengames.com/forums/index.php/topic,1218.msg7959.html#msg7959

It is a fight with two AI-8s and has:
- a low-cost home defense: turrets and forcefields. It is backed up with some mobile reserves on the planet behind it, but these are mostly mercenaries (do not count against unit cap) in low-power mode (use almost no energy). They have not been needed for the past few hours.
- an away team that is about to rip the first Core Planet a new one.

And yes, this is a 1 wormhole defense, but it could be upgraded to three without much difficulties. More than that, and AI-8 becomes infeasible for this strategy.

EDIT: I have no experience in multiplayer, but in single player I consider a total of 10 planets on the high side. Since (I believe) each of you can build energy plants at each planet without negative consequence, I would go for 4 each. Around the 250 mark the AI starts raiding with Mk.II units, and those are vastly more dangerous than the Mk.Is it normally raids with. Keeping the AI below that mark is vital.

An additional point is that losing ships hurts you time-wise, as they need to be rebuilt: try to lose as few as possible. I found out that I really was bleeding on bombers: as enemy long-range cruisers can easily kil these, they die at a frightful rate. Simply using less bombers helped a lot.

[Ashery]

An additional point is that losing ships hurts you time-wise, as they need to be rebuilt: try to lose as few as possible. I found out that I really was bleeding on bombers: as enemy long-range cruisers can easily kil these, they die at a frightful rate. Simply using less bombers helped a lot.

Or not sending a massive wave of bombers head first into a pile of cruisers ;p

But yea, your problem is that you're letting your AI progress get too high and, as Haagenti mentioned, you're fighting them on their terms.

What you want to do is find a cluster of planets (At least six, but less than ten would be a decent range to shoot for) that can easily be defended. Being easily defended does *not* imply the need for a single wormhole to defend, in fact that can actually hinder your progress as the AI will have a similar defense built up due to the fact that they only have one planet that'll be alerted to your presence. Look for a position where there's only a single front of 2-3 planets that are connected as this will allow you to maintain one large defense fleet that you can move to intercept waves at their entry point. TypicallyI'll l eave all of my Mk I ships behind as a defense force and only use their higher quality siblings to actually raid. If you can prevent the AI's from reaching the next tech level, this will work against almost all ships (Exceptions include ships that have no real counter, eg cutlasses).

Also, a sizable amount of data centers will be adjacent to the AI's core planets (six out of twelve were immediately adjacent in my last eighty planet map). How many data centers a thirty planet map will have, I can't really say, but I wouldn't be surprised if most were adjacent to their core planets.

[liq3]

@Haagenti: I checked that save you linked to.

Your strategy only works on non-hub maps (and maybe simple-hubs). Try playing on Realistic Hubs. You're strategy is no where near as effective on it (albeit, it's still probably the best strategy).

In the save'd games case you were playing on a Realistic map and chose an area where you could isolate 6 planets. Using the same seed but on Realistic Hubs and that 6 planet area now has around 4 connections out.

[Haagenti]

I'm trying to defeat the higher AIs, and this means:
- select specific maps
- select specific opponents
to find cases where it can be done.

By gaining experience with special techniques for special cases, I try to find strategies that will then work on lower levels in less special cases. I now have a good idea on how to defend a single wormhole against overwhelming odds with 100% success (unless cutlasses show up)

In the case of more connected maps, the strategy needs to be adapted. I can no longer defend a single wormhole, but I can ensure that most attacks will land at one or two wormholes: 
- select a perimeter, with a relatively limited amount of wormholes
- determine which wormhole is likely to get the most III/IV cross-planet raids. This depends on:
  - where are the closest III/IV planets
  - where are all other planets
- In some cases you must kill a III/IV planet to eliminate it from consideration
- In some cases you must kill an enemy planet and NOT colonize it: this helps to channel the cross-planet raids towards one planet
- Kill all warp gates that are adjacent to other planets.

Most raids and cross-planet raids will now land at one or two wormholes which should be strongly defended. The defense in the save game is experimental and therefore rather an overkill. If you load it in with the newest patch the AI attacks it and loses 6K ships without any turret being damaged. So you can use much less turrets with the same results. I would also mix up my turrets more than I did in the save-game (though that will cost more knowledge), as different turrets work better against different ships. A good mix of MLRS, short-range, lasers and missiles will work better than many of one type.

The other wormholes are able to do with less defense. But note that any wormhole should be covered by at least a II forcefield (later on upgraded to a III), and that you should deploy all your forcefields except a single I (which is needed by your away team). Large stacks of turrets under a forcefield decimate AI forces. Especially if you can keep a cruiser force in reserve to massacre any bomber raids (everything else cannot damage the forcefields quick enough).

If you have 10 planets in your perimeter, you should have an enormous stack of resources. I get plenty of resources from 6 and your power situation is much better with 10, so you should have plenty to spare. Again, I suggest to make the very knowledge-costly upgrade to III Orbitals ASAP to give even more resources (another 300 metal/crystal per second if you upgrade 9 orbitals). The resources can be used to build a large reserve of merc cruisers (normally kept on low power) to counter bomber raids.

I'll start a new AI 8 game with hubs and try to demonstrate (or refute) the above ideas. Though I won't pick Vicious Raider again: it is a real killer even at the start of AI8.

[RCIX]

I'm working with a couple of 7.6's (Random easier/medium) and what i'm doing is using a strike force of 6 raid starships to hit  low-level planets and slim down their forces. I'l usually knowledge raid them then take the planet if it's interesting. Otherwise i leave it alone, command center and warp gate intact. So far it's easy but i'm only a few hours in...