Hello, I am new to Rampant and I am not sure if it is a bug or feature, but I've been playing for couple of hours (evolution factor 0.3745) on default settings without Rampant Arsenal mod. I have a basic jumpstart base and everytime I try to expand out of it by clearing some biters nests around me they just keep making bases somewhere else faster then I can kill the nests. I also tested this several times by loading the save to a scenario and speed up time and if I stay at my base, not a single new nest is created - they are just stagnant, but as soon as I kill some nest, they start randomly expanding and sometimes they wont even stop and expand to the border of my base.

It seems impossible to progress with the game. Is it a bug, or am I doing something wrong? Or this mod isnt intented to be played without the Arsenal mod? If this is a feature, can you point me to a information on how it works - I tried to look, but could not find anything.

This was in versions 2.01.00 - 2.02.00, when the destruction of one nest provoked the growth of others nearby. But in 2.02.01 this was disabled
What version are you using?

I have these versions:
Factorio (Base mod + Elavated rails + Quality + SA): 2.0.60 (build 83512)
Rampant, fixed: 2.2.1

I am also using these mods, but I don't think these could have any impact:
Alien Biomes: 0.7.4
Alien Biomes Graphics: 0.7.1
InformaTron: 0.4.0

Btw. I noticed it in changelog, but there was artillery mentioned and I don't have that researched yet.

Hell, I didn't even launched a rocket when I first encountered the issue. I'm running a tiny base to not upset the locals, not that I have other option cause they just stomp me to the ground :) Now, I am starting to run out of ore patches so I am forced to clean my surroundings - will do another test.

I can send a saved game if needed. Screenshot of my base if it helps in any way: https://imgur.com/a/TBFacQc

Yes, your save will help a lot

Ok, I tested once on my latest save - but I could not reproduce.

My routine test is to destroy one larger enemy base, then head back home, set speed to x64 and watch map for a minute or two.

So I also tested on the save from my yesterday's test - could not reproduce on the 1st try, but on the 2nd I was able to reproduce some expansion (although my yesterday test had much bigger expansion):
Map at the start (with my future route marked): https://imgur.com/a/h3JuNUD
Map after the clearing + couple of minutes on x64 (new nests marked): https://imgur.com/a/73RrQLV

Saves are here: https://drive.google.com/drive/folders/1R1OR94tAQpmVdFEm2mRdOJ-vC2UPn8pY?usp=sharing
scenario.zip is my yesterday's save that I converted to scenario so that I can make some tests - I fortified defenses so that they last indefinitely to fast forward time and there is also a tank prepared for clearing the nests.
latest.zip - this is my latest save that I am currently playing

Based on my testing it seems that the expansion is not triggered every time - either there is some probability or it might be affected by the testing method (speed of the clearing - in test I am done with the nest in 30 seconds, but in game it might take me couple of minutes).

I think I know what happened to you. The destruction of the bases coincided with the AI ​​"siege" mode. In this mode, the AI ​​spends some of its "action points" on creating new bases near the player. Destroying the base gives these "points", and much more than the natural increase.

However, I was going to change this in the next releases, since the player cannot know which mode the AI ​​is currently in. Also, it is planned to weaken the expansion in general, since after the bugfix in 2.02.00, it became too effective. The exact release date is not yet known.

I downloaded the saves, they will help me

Ok, thank you. I confirm that in my latest save it just happened as well - I am too slow to clear bases, they actually expand faster than I can clear them :) I will try to defend until artillery, hopefully that'll do the trick.

I think I know what happened to you. The destruction of the bases coincided with the AI ​​"siege" mode. In this mode, the AI ​​spends some of its "action points" on creating new bases near the player. Destroying the base gives these "points", and much more than the natural increase.

However, I was going to change this in the next releases, since the player cannot know which mode the AI ​​is currently in. Also, it is planned to weaken the expansion in general, since after the bugfix in 2.02.00, it became too effective. The exact release date is not yet known.

I downloaded the saves, they will help me

I will try to beat it anyway, but I have couple more questions, I hope you don't mind...
1) How are the AI modes determined and how often they change?
2) Is the current mode per nest/faction or global for all AI?
3) Could you elaborate on the points calculations? Generation and spending. Some numbers to have an idea how it works.

1. Depending on the presence of nests on the map, their location relative to the player's buildings, losses. AI mode changes every 15-25 minutes, but can be same
2. Global for each surface
3. The more nests and the higher the evolution, the higher the generation over time. Nests close to player buildings (<5 chunks) have a significantly greater effect. Approximate generation: on the deathworld, in the middle of the game, points are generated for about one attack per minute.
   Killing nests with artillery gradually increases passive generation permanently. A single group of nests will not make a significant difference, but constantly clearing large areas with artillery will eventually lead to constant attacks. However, as far as I can see, this doesn’t stop anyone...