How to stop the Prethoryn Scourge?

[Akutagawa]

Sadly the Prethoryn Scourge arrived in my galaxy. It entered the galaxy in the northern part of my empire. It quickly consumed half of my empire and two others. Including most of my race and my homeworld. I fought valiantly with my 70k fleet I destroyed 260 of their ships. Others destroyed 140 Prethoryn ships. The Prethoryn destroyed over 1000 ships already. Now I fortified my position on the northern border of my remaining empire with fortresses and my remaining 40k fleet. There are two Awakened Empires in my galaxy. One with a 600k+ fleet awakened a long time ago. It's on the other side of the galaxy and ignored the Prethoryn threat so far. The other is the Defender of the Galaxy. I have just watched the Scourge obliterate its 150k AE fleet. The scourge has 23 planets and a fleet strength between 600k - 1 million.

How can I stop them? The whole galaxy united under one banner (apart from the other AE and its dominions) against the threat but I see no action. No substantial fleet to counter the Scourge. The Scourge is currently ignoring me. I can stop one of their fleets but not the entire armada. How can I weaken them?

[Half Phased]

Are you using armour busting weapons? Plasma, bombers, tachyon lances are great against the scourge as they don’t have shields. If you need a long ranged weapon to spam against the scourge, kinetic artillery also does the job.

In addition, load up on PD and flak. You’ll need it to shoot down their missiles and fighters.

Finally, choose your engagements wisely. The scourge have warp 3 drives, meaning that short hops don’t take long, but a series of longer jumps grinds their progress to a crawl, and if they arrive on the opposite side of a system relative to your fleet you have time to escape.

[Akutagawa]

Originally posted by Destructively Phased:

Are you using armour busting weapons? Plasma, bombers, tachyon lances are great against the scourge as they don’t have shields. If you need a long ranged weapon to spam against the scourge, kinetic artillery also does the job.

In addition, load up on PD and flak. You’ll need it to shoot down their missiles and fighters.

Finally, choose your engagements wisely. The scourge have warp 3 drives, meaning that short hops don’t take long, but a series of longer jumps grinds their progress to a crawl, and if they arrive on the opposite side of a system relative to your fleet you have time to escape.

I have kinetic weapons mostly. It's quite effective. With my 70k fleet I was able to destroy 3x45k fleets in one battle. Sadly now its bigger fleets are here.

[Akutagawa]

The real problem is their numbers... There's too many of them.

[|☧|r.τ.α|☧| VTitus]

You have to focus on cleansing the planets they take. They will just keep spawning fleets otherwise.

I just started fighting them for the first time after 600+ hours on 2.5x because I found the other end game events to be a little under powered and I am shocked at how strong they are.

My 350k fleet can basically take on about 600k of their maybe 2-3 mil worth of 300k fleets before having to emergency ftl and even with hit and run tactics the whole galaxy has only cleansed one of almost 40 planets they've seized so far.

I did a lot of reading about them and you really have to bait their defensive fleets and hope you have enough time to bombard a planet clean on the opposite end of their territory. It's the only way I even managed to get one of their planets but the AI keeps sending in suicidally small fleets everywhere so I can't really predict their movements anymore and my main fleet keeps getting caught without being able to get any other fleets into position quick enough.

Supposedly you can "starve" them by cleansing all the border planets they control until there's too big a gap for them to warp out of. I don't know if that will really work but it's the only strategy I have, at least to make a barrier on the side closest to my half of the galaxy.

[NixBoxDone]

First: building ships and other prep. The scourge are very heavy on strike craft, missiles and armor backed by huge hull pools.

This means that the weapons you field should be good against armor.
They're also doing quite a lot of damage in medium range, so you can leverage range as an advantage.
Consequently you will want to build huge numbers of battleships with tachyon lances. They have high range, good damage and ignore most of the enemy armor (arc emitters first seemed like a good idea, but they only have about half the DPS of a lance while only ignoring 25 % more armor - not really worth it, in my opinion).

I went with ships that run tachyon lances, plasma and a hangar section fielding fighters and PD slots to take out incoming firepower.

You will still lose ships to missiles (as your PD will mostly hold fire until the scourge bombers get into range, allowing the first couple of salvos to freely sail past and deal damage) but your losses will be limited until the scourge reaches medium range - most ships field a big complement of missiles and hangars backed by a few medium size and range projectile weapons, which will be what will deal damage to you.
The projectile weapons have good accuracy and tracking, good damage and do like 30 % extra shield damage while ignoring 30 % armor, so you want a huge shield tank (backed by capacitors) to eat as much damage as possible, backed by two or three neutronium armor plates to mitigate some of the damage that goes through your shield.
With enough + 5 % armor tech repeatables those 3 modules will get you all the way up to 90 %, making your ships extremely tough.

Try to get an admiral with the + 20 % range buff.




Behaviour: the scourge gain a certain number of fleets as reinforcements every 2 years. The number depends on:

- How many ships they already have (including infestors and troop transports. If they have over 2000, no reinforcements spawn).

- How much of the galaxy they own (certain milestones such as I think 30 and 50 % cause one extra spawn, so the bigger they are the harder it is to diminish them enough that the reinforcements won't just heal it).

They gain territory that they defend and expand by infesting habitable worlds. They will attack the system, destroy static defenses and any defending fleets, bomb the planet, land troops and then, once they occupy the planet, purge the pops on it. This kills the planet, turning it into a scourge goop ball. You can stop this process by invading the planet and killing their troops before the purge goes through.
Be aware that there is currently a bug: if you invade the planet and the purge succeeds before you reclaim it, the planet will turn into scourge goop with your troops still on it, causing it to bug out: your fleet will think it's occupied by you, the event flags will think it's scourge owned.
The solution to this is to destroy all other scourge planets and installations. The scourge will then respawn (as they still have that bugged planet) and attempt to "liberate" their owned planet from your troops.
To do so, the scourge will bomb it to zero. Bombing it kills the scourge goop, turning the planet barren and releasing your troops, winning the crisis.
Ironically, the last victim of the scourge in that case is the scourge. :D

Defensively they will swarm to hunt down and destroy fleets that invade their territory or attempt to bomb their worlds.
If you DO manage to bomb them to zero after they are infested, they become barren and as such useless to the scourge.

Offensively they will attack with one or two fleets at a time - those fleets will NOT receive reinforcements as a rule.




All of this combined means that when you have a fleet that isn't about 10 times the fleet power of an individual scourge fleet, what you will want to do is act defensively. This may seem excessive, but the scourge will frequently attack you with 10 or more fleets at a time, so you need that much to take out satisfying numbers of scourge and to not lose your fleet before it can FTL out. Place your fleet where you can reach the scourge frontier and attack any scourge fleet that attempts to gain ground for the scourge. Have troop transports with you to take back worlds that may have been occupied before the purge goes through and takes the planet away from you or your allies.

If your fleet is too weak, you may try to sneak in and bomb it while the scourge is distracted, but you'll be frequently interrupted.

If you are strong enough to kill a few scourge fleets in a row, a good tactic may be to jump in, wait for the scourge to swarm you and then take out as many ships as possible before emergency FTLing out of there.

Also useful is to have a second distraction fleet. That fleet can consist either of ships of the line (which you can use once you want to strike in earnest) or cheap empty hulls carrying only 1 tier 1 projectile and maximum propulsion/FTL drives.

You send that fleet to edge of scourge territory that is furthest from where you want to regain ground from the scourge. Once you send it into scourge territory there ALL the scourge fleets will route there to destroy it eventually. You then jump in wide circles to cause the scourge to pursue, while sending your second fleet in to attack once the scourge are as far away as possible.

Uusually the scourge will turn around to attempt to stop you from regaining ground, but unless you play on a small galaxy you should have just enough time to bomb down a scourge world and cleanse it, taking back galactic territory to reduce scourge spawns.

Do this until you have enough repeatable tech, mineral/energy income and naval capacity that you feel you can take out 5 or 6 fleets in one engagement without losing your entire fleet.
Tech you want is energy weapon damage/attack speed, shield hitpoints and hull points (armor only until your battleships reach 90 % with 3 armor modules, to find out how much they actually have hover over a battleship in your fleet list, it'll show you the actual stats including strategic resource/research buffs rather than the naked hull stats the ship designer shows you).

THAT'S when you strike. Build up to your biggest sustainable fleet, hit them, take out 5 fleets, FTL out, repair, rebuild, repeat. As long as you take out more than 5 fleets per 2 years this will let you slowly reduce their numbers.
You'll reach critical mass when there are only about 10 fleets left. One more push will weaken them so much that they won't be able to force you to retreat, after that you can just mop them up and go around bombing while your starports build reinforcements - the respawn won't spawn enough fleets to threaten your fleet at that point and all you have to do is make sure you don't let them respawn 3 or 4 times so they can get threatening numbers again.



The rest is just a long, drawn out battle of attrition. You fight the scourge, you take losses, you replenish your ships, repeat as necessary. If you have left-over resources, invest them into colonizing more worlds or building ring worlds/habitats to gain more resources for more ships and more worlds/mega structures.

Eventually you should be able to kick the scourge out by simply stacking repeatable tech and battleships.

[Akutagawa]

Originally posted by NixBoxDone:

First: building ships and other prep. The scourge are very heavy on strike craft, missiles and armor backed by huge hull pools.

This means that the weapons you field should be good against armor.
They're also doing quite a lot of damage in medium range, so you can leverage range as an advantage.
Consequently you will want to build huge numbers of battleships with tachyon lances. They have high range, good damage and ignore most of the enemy armor (arc emitters first seemed like a good idea, but they only have about half the DPS of a lance while only ignoring 25 % more armor - not really worth it, in my opinion).

I went with ships that run tachyon lances, plasma and a hangar section fielding fighters and PD slots to take out incoming firepower.

You will still lose ships to missiles (as your PD will mostly hold fire until the scourge bombers get into range, allowing the first couple of salvos to freely sail past and deal damage) but your losses will be limited until the scourge reaches medium range - most ships field a big complement of missiles and hangars backed by a few medium size and range projectile weapons, which will be what will deal damage to you.
The projectile weapons have good accuracy and tracking, good damage and do like 30 % extra shield damage while ignoring 30 % armor, so you want a huge shield tank (backed by capacitors) to eat as much damage as possible, backed by two or three neutronium armor plates to mitigate some of the damage that goes through your shield.
With enough + 5 % armor tech repeatables those 3 modules will get you all the way up to 90 %, making your ships extremely tough.

Try to get an admiral with the + 20 % range buff.




Behaviour: the scourge gain a certain number of fleets as reinforcements every 2 years. The number depends on:

- How many ships they already have (including infestors and troop transports. If they have over 2000, no reinforcements spawn).

- How much of the galaxy they own (certain milestones such as I think 30 and 50 % cause one extra spawn, so the bigger they are the harder it is to diminish them enough that the reinforcements won't just heal it).

They gain territory that they defend and expand by infesting habitable worlds. They will attack the system, destroy static defenses and any defending fleets, bomb the planet, land troops and then, once they occupy the planet, purge the pops on it. This kills the planet, turning it into a scourge goop ball. You can stop this process by invading the planet and killing their troops before the purge goes through.
Be aware that there is currently a bug: if you invade the planet and the purge succeeds before you reclaim it, the planet will turn into scourge goop with your troops still on it, causing it to bug out: your fleet will think it's occupied by you, the event flags will think it's scourge owned.
The solution to this is to destroy all other scourge planets and installations. The scourge will then respawn (as they still have that bugged planet) and attempt to "liberate" their owned planet from your troops.
To do so, the scourge will bomb it to zero. Bombing it kills the scourge goop, turning the planet barren and releasing your troops, winning the crisis.
Ironically, the last victim of the scourge in that case is the scourge. :D

Defensively they will swarm to hunt down and destroy fleets that invade their territory or attempt to bomb their worlds.
If you DO manage to bomb them to zero after they are infested, they become barren and as such useless to the scourge.

Offensively they will attack with one or two fleets at a time - those fleets will NOT receive reinforcements as a rule.




All of this combined means that when you have a fleet that isn't about 10 times the fleet power of an individual scourge fleet, what you will want to do is act defensively. This may seem excessive, but the scourge will frequently attack you with 10 or more fleets at a time, so you need that much to take out satisfying numbers of scourge and to not lose your fleet before it can FTL out. Place your fleet where you can reach the scourge frontier and attack any scourge fleet that attempts to gain ground for the scourge. Have troop transports with you to take back worlds that may have been occupied before the purge goes through and takes the planet away from you or your allies.

If your fleet is too weak, you may try to sneak in and bomb it while the scourge is distracted, but you'll be frequently interrupted.

If you are strong enough to kill a few scourge fleets in a row, a good tactic may be to jump in, wait for the scourge to swarm you and then take out as many ships as possible before emergency FTLing out of there.

Also useful is to have a second distraction fleet. That fleet can consist either of ships of the line (which you can use once you want to strike in earnest) or cheap empty hulls carrying only 1 tier 1 projectile and maximum propulsion/FTL drives.

You send that fleet to edge of scourge territory that is furthest from where you want to regain ground from the scourge. Once you send it into scourge territory there ALL the scourge fleets will route there to destroy it eventually. You then jump in wide circles to cause the scourge to pursue, while sending your second fleet in to attack once the scourge are as far away as possible.

Uusually the scourge will turn around to attempt to stop you from regaining ground, but unless you play on a small galaxy you should have just enough time to bomb down a scourge world and cleanse it, taking back galactic territory to reduce scourge spawns.

Do this until you have enough repeatable tech, mineral/energy income and naval capacity that you feel you can take out 5 or 6 fleets in one engagement without losing your entire fleet.
Tech you want is energy weapon damage/attack speed, shield hitpoints and hull points (armor only until your battleships reach 90 % with 3 armor modules, to find out how much they actually have hover over a battleship in your fleet list, it'll show you the actual stats including strategic resource/research buffs rather than the naked hull stats the ship designer shows you).

THAT'S when you strike. Build up to your biggest sustainable fleet, hit them, take out 5 fleets, FTL out, repair, rebuild, repeat. As long as you take out more than 5 fleets per 2 years this will let you slowly reduce their numbers.
You'll reach critical mass when there are only about 10 fleets left. One more push will weaken them so much that they won't be able to force you to retreat, after that you can just mop them up and go around bombing while your starports build reinforcements - the respawn won't spawn enough fleets to threaten your fleet at that point and all you have to do is make sure you don't let them respawn 3 or 4 times so they can get threatening numbers again.



The rest is just a long, drawn out battle of attrition. You fight the scourge, you take losses, you replenish your ships, repeat as necessary. If you have left-over resources, invest them into colonizing more worlds or building ring worlds/habitats to gain more resources for more ships and more worlds/mega structures.

Eventually you should be able to kick the scourge out by simply stacking repeatable tech and battleships.

WOW, this is a very informative and detailed answer. Thank you!

[NixBoxDone]

No worries. I just got done watching a streamer fight the scourge and that's the method he used to beat them. When they spawned he had about 90 k in fleet power and each scourge fleet had about 150 k.

They quickly lost about 2/3 of the galaxy (the galaxy was fighting an AE, so many fleets were devastated and the AE was busy pounding other AIs instead of holding back the scourge).

Using above tactic he was eventually able to destroy what was (at that point) about 2 million in scourge fleet power pretty much on its own. The AI helped here and there, but it also derped up and led the scourge to him often enough.

The most important point is to know when to retreat (i. e. when the scourge fleet draws close enough to significantly damage your fleet with their projectile weapons) so that you don't lose your entire fleet and become helpless and to prioritize keeping the scourge from growing over trying to take back territory.

It's much easier to beat 1 scourge fleet to prevent them from taking a system than it is to play cat and mouse with 10+ scourge fleets to attempt to bomb a scourge planet once they have it.

Btw, he did this without defender of the galaxy, so if you can get that you'll be 1 up on him. ^^

[_ALuX_]

Steel yourself in your devotion to the Emperor!

[Akutagawa]

Originally posted by NixBoxDone:

No worries. I just got done watching a streamer fight the scourge and that's the method he used to beat them. When they spawned he had about 90 k in fleet power and each scourge fleet had about 150 k.

They quickly lost about 2/3 of the galaxy (the galaxy was fighting an AE, so many fleets were devastated and the AE was busy pounding other AIs instead of holding back the scourge).

Using above tactic he was eventually able to destroy what was (at that point) about 2 million in scourge fleet power pretty much on its own. The AI helped here and there, but it also derped up and led the scourge to him often enough.

The most important point is to know when to retreat (i. e. when the scourge fleet draws close enough to significantly damage your fleet with their projectile weapons) so that you don't lose your entire fleet and become helpless and to prioritize keeping the scourge from growing over trying to take back territory.

It's much easier to beat 1 scourge fleet to prevent them from taking a system than it is to play cat and mouse with 10+ scourge fleets to attempt to bomb a scourge planet once they have it.

Btw, he did this without defender of the galaxy, so if you can get that you'll be 1 up on him. ^^

In the end I simply restarted the game. Finally the stongest AE attacked the Scourge with a 716k fleet and it was defeated by 2 million Prethoryns in one battle!!! At that point I gave up. In my new game the crisis strength is merely 0.25.

[NixBoxDone]

Haha, nobody blames you. Beating a crisis is done in two ways: if you're strong enough you crush it before it can get started, if you're not you either fight for a very long time or throw in the towel.

Play the game in a way you enjoy. ^^

[Akutagawa]

Originally posted by NixBoxDone:

Haha, nobody blames you. Beating a crisis is done in two ways: if you're strong enough you crush it before it can get started, if you're not you either fight for a very long time or throw in the towel.

Play the game in a way you enjoy. ^^

Yeah, although I find these unbeatable events ridiculous. You don't have a chance at all. It ruins the game.

[NixBoxDone]

It's not like you have no chance: you can snowball hard and beat it immediately, you can have enough strength in your federation to beat it or you can slowly grind your way through.

Either that or you can disable them on game creation by setting the FEs to zero and disabling end game crises. ^^

[menasure]

It's a scourge alright. In my current game it's the year 2571, i've 77 planets, a score of more than 120K, which is about 50K more than the nr2 empire but my full fleet is destroyed for the 5th time by the spawn of the prethoryn scourge who own ... just 10 planets at the other side of the galaxy.

The thing is: the scourge spawned literally at the other side of the map where they did not meet any serious opposition. Even then they hardly even get to one of my borders if i just let them because of the distance. The scourge prefers to swarm around in its own neighborhood. This allows you to play defensively to build up the fleets you need to face them.
However meanwhile the other AI's and my own alliance members just don't seem to be able to coordinate a single useful action against them, except for one awakened empire which at one point directed all of it's fleets against the scourge ... this awakened fleet will never recover in time to be of any assistance in defeating the pretoryn scourge.

To make matters worse some of the other AI's just close their borders from time to time, immediately isolating my entire fleet during my attempts to deal with the scourge. I've considered attacking those AI's to secure the lines to the scourge but usually my own alliance objects ... not that i really need an alliance but i've switched sides a few times already and it does not feel natural to play that way. So ... eventually i saw no other choice than to build a gate at the other side of the map and build a big station there to be able to maintain a steady flow of reinforcements. It's a tactic which works but the gameplay ends up in a lot of grinding so ... eventually i'm fed up with this set up.

According to the game's rules nobody can win because of this 'crisis' but it actually poses no threat to my empire. Meanwhile all the other empires are also considered 'pathetic' compared to my empire so the game becames one big silly situation where it just feels like the pretoryn scourge can keep this 'scourging' up for a looooooong time ... i could put in the effort to defeat them but the gameplay just feels like a pathetic grind so i just quit my current game. I'll probably start over with different, more fun-guaranteed settings with less 'scourge'.

[Bozobub]

Of note, I believe the 20% range buff is still bugged/nonworking.

[Nightmyre]

Originally posted by Bozobub:

Of note, I believe the 20% range buff is still bugged/nonworking.

Works perfectly fine, AFAIK.

I always put the full 50% bonus on my fleets - from the admiral trait, the war doctrine, and the combat computer.

The ships will still close to 80 yards as the combat computer indicates, but they will shoot from further out. Often this lets you get two shots before the AI can get a single one.