AI not upgrading its planets at all on Hard difficulty (save game included).

This is a problem i have constantly seen since i started playing Sins 2 on Steam.

AI just does not upgrade its planets, even on the Hard difficulty.

Started a 1v1 match today, after 45 minutes the AI has all of its conquered planets between level zero (0) and two (2).

AI has invested nothing into their development and it is completely ruining the game since AI has no economy nor defenses nor empire.

The higher difficulty AI is unfun because of the cheated resources causing the AI to start multi-front "split pushing".

But the non-cheating Hard AI seems to be literally non-functional.

I do not see any way to attach a save game file to this forum so i had to upload it elsewhere and post as a link:

https://limewire.com/d/XxQhj#kduuAvjCdk

 

Please fix this issue so the AI always max upgrades its planets and actually has an economy and defenses.

Thanks.

10,606 views 11 replies
Reply #1 Top

Hmm. I'll have to ask someone about this.  Is anyone else seeing this beavior?

Reply #2 Top

I've got this logged as a bug, we'll take a look at it. Thanks!

Reply #3 Top

Thanks for replying and taking a look at the AI bug!

Can you please tell me do you know is there any way to avoid this AI bug happening?

I would love to again regularly play Sins 2 (i only did 1v1 vs Hard AI [non-cheating] on the smallest maps), but in my past experience this bug has happened almost every match and it just makes the game unplayable since the AI has no infrastructure nor defenses built up.

Reply #4 Top

I don't think I've ever seen the AI do this - the economy and empire is always developed.

 

Now defences on the other hand, those are indeed a problem. Most planets have few to no defences, and even when playing TEC Enclave the AI doesn't garrison its worlds. An extra free 500 supply + 500 supply from all neighbouring garrisoned planets, would really change invasion dynamics!!!

 

I don't think I've ever seen double starbases either. Nor starbases outside the AI's own worlds. When playing with friends we sometimes stack starbases at critical points e.g. one star with something like 12 starbases deployed to it. 

 

The AI also seems to fail to use the Advent's Unity powers, or is it they don't spend the points?

 

I think the bigger issue, especially on higher AI settings e.g. Impossible, is that the AI is locked into a Zerg rush strategy and never really builds defences meaning you need to be able to either outproduce the 'cheating' AI, else tech up and lockdown invasion routes, but building up for a 3,000+ supply invasion isn't easy! 

Reply #5 Top

Hi Devs,

First off, I want to say how much I’m enjoying Sins of a Solar Empire II.
The early‑game experience is fantastic — the pacing, visuals, atmosphere, and overall feel of the new engine are genuinely exciting. Every time I start a match, I’m reminded of why I love SINS 2, and I can’t wait to see how the game evolves as development continues into the future.

However my friends and I have been playing a lot of matches lately, both vanilla and with non‑balance mods, and we’ve consistently run into an issue with the AI that seems independent of modding and which sounds a lot like this post here.

 

Summary of the AI Problem

Across many games, we’ve noticed that AI factions tend to stall out around the 30–60 minute mark:

  • AI stops developing their planets (few or no new structures).
  • Research progression slows dramatically or stops.
  • AI fleet production falls off heavily, leaving them with almost no mid‑ or late‑game presence.
  • Even on larger maps, AI empires on the far side of the map collapse instead of growing into meaningful threats.

This creates a situation where the early game is enjoyable, but the mid‑ to late‑game never reaches the memorable escalation

After about an hour, many AI players look “abandoned” — planets under‑developed, fleets tiny, little tech progression, and no meaningful resistance.

The issue happens under all combinations we’ve tried:

  • Vanilla (no mods at all)
  • Light mods (cosmetic only)
  • Hard/Unfair AI or higher
  • Various map sizes, especially large ones
  • Quick Start enabled or disabled

The AI consistently stalls regardless of settings.

Is there any things in the pipeline to get the AI moving again?

Thanks so much for the amazing work on Sins 2 - my friends and I love it and hope the challenge returns so we can get back into more...

Best Wishes

Reply #6 Top

Hi mates,

I play against hard ai (only vanilla) most of the time, and I see the same limitations to the AI. 

In my opinion, they built up their fleet without any backup-plan. Rushing to max fleet cap and sometimes against me.

One hour into the game you can defeat the first enemy fairly easy if you built up your own fleet fast and strong enough, because your foe has just his blob you need to eradicate. After that, there is no defence preventing him from losing. 

The longer I play, the more I research, the more I get the feeling that my enemies don't do research at all. 

After two hours there is almost no fleet composition capable of defeating mine. 

But when I check the stats afterwards, the economy of some of my foes was really strong so they should be able to build up even defence or research.

Could be subjective of mine, as I don't play against unfair that often. But when I do, I get the same feeling (if I can handle the first death blob).

Loving the game anyways and I had a lot of fun with it. 

mfg

Reply #7 Top

I just encountered this bug in the latest hunt for booty patch. Before this patch the hard AI would always build up at least some sort of defense/supply line on their captured planets. Now they capture and move on, which is hardly any fun as I can just steamroll their planets. Has anyone found a fix for this bug? Haven't tried going against harder AI, so not sure if the problem occurs there as well.

Reply #8 Top

Hi @LordBasura,

I’ve tried several mods that adjust AI aggression, but none of them made a meaningful difference. After digging through the available documentation and modding tools, it looks like most of the AI’s core behavior is handled internally by the game’s executable.

@Devs — Is anyone on the team able to comment on the current modding limitations for AI behaviour or whether deeper access might be planned? or a fix for the AI bugs

As always, the game is fantastic — it would just be great to see the AI refined in future updates.

Reply #9 Top

I posted this on discord but i will also post it here as well since the identical problem still exists.

Replay file is from a 1v1 game played on 6th march 2026.

I have to post it like this since this forum does not have an option for attaching files:

https://limewire.com/d/nxEnB#vUVxcnunNy

Reply #10 Top

Hello again, 

i found another weakness in the AIs behaviour..

We've played 3vs3 on Gateway (my favourite Rebellion map) with 4 unfair AIs (2 Aggressive, 1 Defensive).

Next to my cluster was a plasma storm, three phase lanes from my planets ended there. 

I played Enclave and had all planets garrisoned. 

So, inside the storm it's impossible to fire rockets or to  start fighters. Therefore the battles are really slow, especially with TEC and Vasari if they tend to built a Knarak, Javelis and Carrier Fleet.

They frequently flew to the storm, later on with 1500-3000 fleet supply, and hang and stacked there forever just because of my garrisons frequently sending in light ships (250 supply per Planet). Which they easily destroy but it takes way to long for them because of their fleet composition. Like a gameplay loop.

I call this a ship sink :D Even with attacking their planets and finally defeating there home planets, their fleets sticked to the storm. They should pass by or try another choke point (the first should be an easy task for an ai I guess). In rebellion, the enemy tends to retreat way earlier. In Sins II often to late, especially because the gameplay is faster than in rebellion.

Besides that the overall (ai) performance was not that good either. Our member got in trouble because his fleet were everywhere, but not defending his planets (they had like nothing on them as well, only one star base after he nearly got eradicated. He refused to build more defense anyways).

It took a while for the enemys to send the first death ball, I was ready then. Afterwards we crushed them easily. 

Of course it's hard to find the right balance, I don't like to get crushed after few minutes into the game as well because of a over performing ai. But I think few months ago it was harder to stand against hard ai - and this time it were against 3 unfair. 

Never mind! 

See ya.

Reply #11 Top

Hello guys, thanks for reporting on all the AI issues!
Team is cooking but AI cooking always takes a bit more time. 

Responding to Dentonjdb - AI modding is very limited, as it's within the core logic of the game.