About Cross-Planet Attacks

[Captain Cake]

Alrighty, so after a pretty epic game with a friend we got wiped out by a Cross-Planet Attack of about 1600 3550 ships. There was a rebel colony about 5 jumps from any of our systems so I flew out there and managed to secure the system and toss up a fortress before it decloaked. I left about 2/3 of my fleet at the rebel colony and my friend kept his fleet back at our home systems to defend against the CPA. Unfortunately for me I didn't know that Fortresses only do 1% of their damage to fighters or bombers (first time using them (only about 5 games under my belt, all losses so far ><)) so that pretty much sealed its fate when a whole ton of ships jumped in (round 800 or so I think). After they toasted my fleet they went strait for my friends main defense (keeping in mind the system they came through went also connects to much less defended systems). Now with a threat of 1600 3550 theres no way he could have held them back so that was game. I read stuff about CPAs before and thought they would spread out their forces amongst all of our planets but this doesn't look like that in the slightest. So that leads me to a couple questions..

1. How does it choose which ships to add to your threat level?

2. If I've got a pretty solid defense on all but one of my planets will all of the threat head to that planet since its my weakest defended?


I don't see a reason if the AI has a fleet of 1600 3550 ships for them not to fly everything into my front door. I figure if theres a way to determine where the threat is coming from I can send my fleet there to blow up some of the threat before it can mass for a huge assault (assuming it does that, I don't really see why it wouldn't tho). Any advice or info to help deal with CPAs would be appreciated, because with my current understanding of CPAs it doesn't seem like I can possibly defend against it if they just horded me one system at a time.


EDIT: Loaded my autosave from just before I died and found the CPA was 3550 ships.

[Kaptein]

thats... alot of ships, for 2 player? how many planets have you taken?

[x4000]

Alrighty, so after a pretty epic game with a friend we got wiped out by a Cross-Planet Attack of about 1600 ships. There was a rebel colony about 5 jumps from any of our systems so I flew out there and managed to secure the system and toss up a fortress before it decloaked. I left about 2/3 of my fleet at the rebel colony and my friend kept his fleet back at our home systems to defend against the CPA. Unfortunately for me I didn't know that Fortresses only do 1% of their damage to fighters or bombers (first time using them (only about 5 games under my belt, all losses so far ><)) so that pretty much sealed its fate when a whole ton of ships jumped in (round 800 or so I think). After they toasted my fleet they went strait for my friends main defense (keeping in mind the system they came through went also connects to much less defended systems). Now with a threat of 1600 theres no way he could have held them back so that was game.

Bear in mind if just one of you loses your home planet, the game is not over -- as long as you both don't lose them, you're both still good to go, same as with the AI when it loses one of its two homes.

I read stuff about CPAs before and thought they would spread out their forces amongst all of our planets but this doesn't look like that in the slightest. So that leads me to a couple questions..

The ships choose where to go individually, so generally that means they will spread out more.  But sometimes they will all cluster more, it just depends.  The more planets you have bordering AI planets, the more likely you are to see a dispersed effect.  If you only have one or two planets next to AI planets, you'll wind up with more of a bottleneck.

1. How does it choose which ships to add to your threat level?

It is based on the ships being the level of the current tech level of the AI (based on AI Progress), and then it pulls from the planets that have the most of those kinds of ships first, then from various other planets.  If there are a huge number of ships of that level at one planet, then they might all come from that location.  That can also lead to more of a concentrated effect.

2. If I've got a pretty solid defense on all but one of my planets will all of the threat head to that planet since its my weakest defended?

No, they don't have any information about your defenses, and won't weigh that at all.  They choose target planets largely at random, and then the actual tactical AI kicks in once they get there.

I don't see a reason if the AI has a fleet of 1600 ships for them not to fly everything into my front door. I figure if theres a way to determine where the threat is coming from I can send my fleet there to blow up some of the threat before it can mass for a huge assault (assuming it does that, I don't really see why it wouldn't tho).

They don't have a coordinated central controller, so they will individually seek out planets that belong to you, and eventually find their way to more vital and/or lesser-defended planets based on what they find at each planet.  If you can kill them as they stream into your planets, that is often the best way to handle them.  Or, create one big deathtrap bottleneck if you have a location suitable to that, either way.

Any advice or info to help deal with CPAs would be appreciated, because with my current understanding of CPAs it doesn't seem like I can possibly defend against it if they just horded me one system at a time.

Generally, the best answer is turrets.  Turrets are more effective than mobile ships, in general, but have the disadvantage of not being able to move.  So building some basic, MLRS, and laser turrets is also an effective way to kill a bunch of enemy ships, especially if you pair that with tractor beams to keep the AI ships from passing by.  Minefields can also work, but are often less cost effective and less effective in general when there are a ton of enemy ships.

A couple of other cool tactics and notes that you can use, I'm sure other players will add more:

- Put forcefields on top of wormholes to prevent ships from escaping through them too quickly.

- Place your turrets and military ships outside of force fields so that they are still attacking at full power, while the AI is trying to get to the force field to beat it down.

- Consider spider turrets and other ships that damage engines from afar, as those can completely disable a fair number of enemy ships by stranding them out in the middle of nowhere, for you to go clean up later at your discretion -- in the meantime, your other ships can be mopping up those ships that still do have engines, thus splitting up their forces to the point that you can do a lot of damage against them.

- If all else fails and you are facing a superhuge CPA (much larger than 1600, more like 6000+), you can always take actions that cause them to clump, then nuke the planet they are on.  It's better than a loss, at any rate.  But, with 1600 ships only, careful use of turrets paired with your mobile ships should handle them quite well.  You might lose some planets based on abandoning those while you concentrate your defenses elsewhere, but those are quickly recaptured as long as you don't die.

Hope that helps!

[x4000]

thats... alot of ships, for 2 player? how many planets have you taken?

This past Saturday, in my 3-player game, we had literally a CPA of 9600 ships.  We had an AI Progress that was far too high, around 660, for only being 8 hours in and having around 10ish planets.  We'd lost two captive settlements and used a nuke... blah.  We managed to kill around 3500 of the ships from the CPA before we bit it.  We were going to make a nuke as a last defense, but it occurred to us too late and we didn't solve it in time. This was against two 7s on a vines map.

One thing for the next beta version is going to be making the multiplier for CPAs be less severe with multiple players.  Right now the CPA size essentially is multiplied by the number of players, which is far too much of an increase as more players go up.  In our situation in my game, the CPA should have been more like 4,000 ships I think.  Still would have been brutal, but I think we could have pulled that one off even without the nuke.

At any rate, that change would also make it so that the 1600 wave of ships in this game would be more like ~1150 instead.

[Captain Cake]

thats... alot of ships, for 2 player? how many planets have you taken?

I loaded up my last autosave and found out the CPA size was 3550 (I forgot we obliterated the 1660 CPA) and I attached a pic of the galaxy map. Our AIP is higher than it should have been (we went around popping a few unnecessary command stations only about 40 AIP) and we didn't have too many planets (I blame that on the rebel colony on the far right of the map)

Bear in mind if just one of you loses your home planet, the game is not over -- as long as you both don't lose them, you're both still good to go, same as with the AI when it loses one of its two homes.

My friend was staying back on defense for the most part while I want around causing problems, his defense fleet got obliterated and my fleet (mostly destroyed) was like 7 jumps out, couldn't have made it back to defend against those numbers unfortunately.

No, they don't have any information about your defenses, and won't weigh that at all.  They choose target planets largely at random, and then the actual tactical AI kicks in once they get there.

But after they show will they re-evaluate the situation and skip out to help assault somewhere else?

Generally, the best answer is turrets.  Turrets are more effective than mobile ships, in general, but have the disadvantage of not being able to move.  So building some basic, MLRS, and laser turrets is also an effective way to kill a bunch of enemy ships, especially if you pair that with tractor beams to keep the AI ships from passing by.

My friend had pretty much every turret he could muster on the gate they jumped through and his fleet of about 700 ships, though unfortunately it couldn't stand up to 3000 ships.

- If all else fails and you are facing a superhuge CPA (much larger than 1600, more like 6000+), you can always take actions that cause them to clump, then nuke the planet they are on.  It's better than a loss, at any rate.  But, with 1600 ships only, careful use of turrets paired with your mobile ships should handle them quite well.  You might lose some planets based on abandoning those while you concentrate your defenses elsewhere, but those are quickly recaptured as long as you don't die.

What sort of things can I do to attract the AI to one place? I'm just a little confused since you said that the CPAs will generally be dispersed and attacking from all over and don't get drawn anywhere in particular.

[Doddler]

From what I've encountered of cross planet raids, they are very rare (2-5 hours between raids rare), and almost always huge "OH SH*T" moments.  The risk is that they are usually very large, usually outnumbering your ship count by a good amount, and they don't have an announced or even one direct point of entry, and you won't know where they appear until it's difficult to react.  As far as I'm concerned, aside from massive oversight or huge mistakes, these raids are also the only real threat of losing after you've gotten yourself established a couple hours in.

As far as I know, interplanetary raids are formed by releasing reinforcements across a whole bunch of AI planets at once as threat.  This generally means a couple things, mainly that the bulk of the ships will probably come from systems that are alerted to you and stockpiling ships.  That also means that any system adjascent to you is a potential source of attacking.  My understanding is that interplanetary attacks tend to be of the level of the AI, so you can probably narrow down where those ships will come from based on tech level of nearby worlds.

If you've been pushing against the AI in a specific direction, you can reasonably expect that the bulk of the attack will come from a centralized region, which can make things harder for you. I don't think the AI does any hard thinking about where it will attack you though.  The ships more or less are pick a nearby system, group up and start blasting, making decisions on where to go after that mostly at random.  They don't have a lot of forsight about what structures or units you have there until they actually are in a system, so they may not move around like you'd expect them to.

Generally what I do when I see an interplanetary attack preparing, I fall back on systems I absolutely need to defend (home system, zenith power, Mk4 factories, etc), and ignore the rest.  Once you have a good idea where the bulk of the enemies are coming from you can start trying to cut them off from doing more damage.  It's not uncommon that I lose half or more of my command centers to these attacks, but rebuilding isn't that hard.  It's really important though that you have an idea of where the ships might be coming from.  Ships tend to gather on portals waiting for friends to arive before making the dive into your systems so having scouts in nearby systems can give you some advanced warning (they won't actually start grouping until the countdown hits 0 though).  Given the relatively slow nature of interplanetary attacks, once you know where the bulk of the threat is coming from you should have enough time to react.

[x4000]

AI ships in CPAs come from planets that have a lot of AI ships on them of the correct level, so you can anticipate directionality somewhat based on that -- the most AI ships tend to build up around your borders.  Doddler gives a great rundown on that, his analysis is spot on.  Other notes of mine:

To make it more dispersed:
- If you neuter those planets (killing the guard posts), there will be significantly fewer ships at any given point, making the attack far more dispersed.
- If you have taken a lot of planets that border a lot of enemy planets of the correct mark level, then they will all have moderate reinforcements at them, most likely, also making the attack more dispersed.

To make it more concentrated:
- If you put very few AI planets on alert (as with vines or snake maps, for instance), then AI ships will tend to pile up in very high numbers on the few planets that are on alert.  Assuming that one or two of them are the right mark level of planet, you can guess that most of the attack would come from those few locations.  Of course, if you carry this too far and there are not enough ships on those alert planets, then you'll flip over into making this more dispersed again because more ships will join the CPA from wherever else out in the galaxy.

In other words, the CPA is weighted towards the largest planets that have ships of the appropriate mark level.  The AIP in that screenshot really was not enough to make it truly brutal by design, I think the part that is the problem is that multiplayer multiplier.  In the next version when that change is in, it should be more like 2307 ships there.

What I meant about drawing the AI into bottlenecks is using natural bottlenecks that exist on the map.  If you build outward to that you tend to have very few wormholes leading to AI planets from your core areas, as many players tend to do, then often there are a few natural choke points that you can identify.  Unfortunately, with a grid or hub type of map as in that screenshot, often those sorts of choke points don't exist.  In that case, going nuts with the turrets, and packing extra force fields to create bottlenecks by preventing ships from using specific wormholes or getting to specific command stations, can serve the same function.

When you don't know what direction they will be coming from, as with your screenshot there, that's a tricky on.  If it were me, I probably would have done the following, but this is just me:

- Bring all mobile forces back to the two home planets (the rebel colony can fend for itself for two hours, after all).
- Unlock Spider Turrets for sure, and build them off by themselves on both home planets, and possibly also on some of the other random player-controlled planets.  This is better done far in advance, and helps in defending in general.  But basically the idea here is to whittle down the enemy forces by knocking out engines before they reach your home planets.  But if they don't go through other planets of yours, then that is a waste, so you're kind of betting there.
- If there is enough knowledge, unlock Laser Turret 1 or Laser Turret  2, or MLRS Turret 2, and build those like crazy around all wormholes on both home planets.
- Otherwise, just build whatever turrets you have around the wormholes on both planets, along with at least 15-25 tractor beams at each wormhole if possible.
- Put double forcefields or more up around the home planet command stations, and turrets all around them.
- Put minefields on the most likely paths to the home planet command stations.
- Put all my ships in FRD mode, and have some engineers hanging out to repair stuff if it needs be.


Then, if the AI attacked me on whatever other planets, I'd only make small motions to try to slow them down, token resistance.  If they were coming in fairly dispersely, I might send out my fleet to pick them off, but if I started getting outnumbered I'd retreat back home.  I'd have a scout on any enemy planets adjacent to my home, and I'd be watching the numbers of enemy ships on those planets very intently to make sure that nothing was coming at me from behind.

Other things that might help, factoring into one plan or another:
- Starships to boost munitions.
- Lightning Warheads to take out large groups of ships right as they are gathering on the other side of a wormhole to come to one of my planets (again, having scouts sitting there on those planets) -- one lightning warhead, if you're lucky, can take out 500-700 ships, depending.  They can be an incredible boom.
- EMP Warheads could be used if too many AI ships are all on the far side of a single wormhole from your fleet.  Send the EMP through, and then immediately your fleet, and you've got 30 seconds to butcher them while they are paralyzed.  Pair that with first sending through a lightning warhead, and you're suddenly on very even turf.
- As noted in the past, you can use forcefields over wormholes to slow them down.  Works great when paired with turrets around the forcefield, or with spider turrets elsewhere on the same planet. If you have enough warning as to where the enemy is coming in (if it is through a chain of your planets), that gives you time to get forcefields in place since they are mobile.
- Also as noted in the past, as a measure of last resort you can resort to a nuke or two to clean off a planet.  If it's your planet that is going to cost you resource income as well as AIP (since the harvester spots are destroyed), so that's a really tough call to make; but it's better than outright losing.

[Kjara]

When considering the nuke option if you are pretty sure that a large number of their forces are coming from the same planet(aka its the right mark and its got a huge buildup)--then preemptive nuking can be good if you really don't think you can handle the cpa.  Much better to nuke them before they come then to try to nuke them on one of your own planets .

[x4000]

When considering the nuke option if you are pretty sure that a large number of their forces are coming from the same planet(aka its the right mark and its got a huge buildup)--then preemptive nuking can be good if you really don't think you can handle the cpa.  Much better to nuke them before they come then to try to nuke them on one of your own planets .

Definitely.

[Chimpster]

I've had something simmilar happen recently.

Just about to invade my fourth system so an extremely low AI progress score so I'm tinkering with the fleet and preperations.  I have a quick look on the galaxy map only to find that there are 500 enemy ships in one of my sectors    Not only that, but there are 400 Core Missile Frigates in the system without warning (and no AI homeworld nearby according to my scouting ).

Incredibly, I actually won the battle with 100 shredders and 50 mk2 Bombers with pretty much 0 extra defence   End result was this screenie...



Twas a great victory

[vonduus]

x4k, all this advice on how to withstand CPAs ought to be put in the wiki. The information in the wiki is good, this is far more comprehensive.

And CPAs are in my opinion the greatest challenge of all in this game. I have beaten the game a few times now on level 6, and compared to surviving a CPA, killing a few mother planets is piece of cake. After loosing and having given up on uncountable games, it was almost an anticlimax just to walk in and kill the AIs homebases. I am moving to level 7 and the expansion now, and I feel quite confident that I can cope with the regular AI. My only worry for the future is the CPAs. I still fear them, and I am not a total newbie anymore! Newbies should have all the help we can provide on CPAs.

[HellishFiend]

Thar be some great info in this here thread!

Also, I've learned that X and I have vastly different strategies when it comes to dealing with CPAs. I never give up on a frontline planet under any circumstances. I will have all of my heaviest defenses in place on my frontline perimeter, and my homeworld defense comes in the form of contingency plans (which I rarely have to rely on  ).

This may sound a bit extreme, but I would rather leave a planet uncolonized than be faced with the scenario where I do not have the resources/ship cap to defend it. I operate best when I feel and know that all my frontline planets are adequately defended against attack.

And now for some advice! One of my favorite defensive strategies may be a bit unconventional: unspent resources and ship/turret cap.

Unspent resources and ship/turret cap is just as good, if not better, than actual turrets and ships, because you can reactively build anywhere in an instant using engineers. Proactive defense is more conventional, but with AI war, reactive defense tends to be just as, if not even more effective.

(For purposes of comparison, I play on non-F&D, difficulty 7)

[Goekhan]

well, once I used 4 forcefields to trap them at the wormhole, then one lightning warhead did the job. Pretty funny

[Captain Cake]

And now for some advice! One of my favorite defensive strategies may be a bit unconventional: unspent resources and ship/turret cap.

Unspent resources and ship/turret cap is just as good, if not better, than actual turrets and ships, because you can reactively build anywhere in an instant using engineers. Proactive defense is more conventional, but with AI war, reactive defense tends to be just as, if not even more effective.

I'll have to give this a shot as your play style seems similar to mine, though most of the games I play are with a friend so our strategy is a little different (no idea how viable it is since we've yet to win a game). I run an offensive fleet and go after appropriate tech (barely spend any of turrets, pretty much spider turrets if its needed), and my friend focuses on a defensive fleet and tech (he loves his mark III tractor beams).

What is everyone's opinion on this when it comes to CPAs?

Am I losing out hard by ignoring turrets and leaving them all up to my friend?

Biggest problem is that my fleet is almost always away from home doing something so it things start to go wrong I don't really have a fleet to supplement our defenses. I know that flying my fleet around alerts nearby planets, increase the odds of them getting reinforced. Although I'm increasing the number of planets on alert the number of reinforcements won't change just the number of systems that are likely to receive reinforcements right (diluting the number of reinforcements at each planet)? Or am I horribly wrong about that?

[Doddler]

After loosing and having given up on uncountable games, it was almost an anticlimax just to walk in and kill the AIs homebases.

Actually, it's kind of funny, the cross planet raid is the most formidible and downright scary weapon the AI wields against you, and I wouldn't have it any other way!  But the AI wields it randomly, which is also good, you shouldn't know when it will come because that takes the challgne out of it...  But I kind of expect a similar reaction from the AI when say, we blow up one of the AI homeworlds, or we're about to win the game and attacking their last homeworld, but they don't really react to those situations and it's a little anticlimactic.