Border agression oddities

[Vinraith]

I'm not sure if this is a bug or if there's something I'm not understanding, but on AI Level 6 with an AI progress of 368 we're seeing a steady stream of core ships from the AI homeworld due to what looks an awful lot like border aggression. The thing is, there are only ~3000 ships on those worlds, so I don't understand why we'd be seeing BA at this point. I'm not sure what's going on here. We started this game on 3.172 and have updated to the newest beta (3.175 as of posting), but have not activated the second expansion on this game. I'll include a save game, and you'll be able to see a steady stream of core ships moving from the AI homeworld at Jiubisa all the way down to our front lines at Disan 12 hops away.

[x4000]

I have not had a chane to look at this save yet, but I can say that if thereare very fee planets on alert, and the homeworld is not on alert --  or, alternatively, if the homeworld is alerted -- you would see a large buildup on the home planet, with the overflow going to border aggression. One way to stem the tide might be to alert some more planets. The other way would be to kill that homeworld or not alert it in the first place.

Generally the homeworlds get reinforcement primacy when on alert, and can often take 2 reinforcement points instead of one out of the pool the ai has if it is actually on alert, so this can definitely happen. In my current multiplayer game I'm seeing something similar from where my teammates capped a core planet next to one of the home planets while I was away for 3ish months.

I have some non-expansion-related ships I plan to add this week in order to at least provide more options in those sorts of scenarios. So maybe that will help for you also, not sure. I can't heck the save right at the moment as I'm not at a computer.

Hope that helps!

[Vinraith]

Thanks for the response, x.

We have a number of planets around us on alert, but all have been neutered. In that situation, with alerted planets "full," am I understanding that the AI preferentially reinforces the AI homeworlds and the type IV worlds immediately around them?

Even given that, though, the populations at those worlds are too low to be causing border aggression at our present difficulty and AI progress, unless the calculation documented in the wiki has been significantly changed (or I've misunderstood something). 

[x4000]

Sure thing, Vinraith.

The AI doesn't necessarily always preferentially reinforce the AI homeworld and mark IV works around them (the "core" worlds), but it definitely does have a chance of doing that.  In your case, sounds like that is what they are doing.  Bear in mind that the AI uses a unified ship cap when deciding how to reinforce or do ship overflows on a planet, so if there were (say) 1000 permamines, that could do it.

The ship cap is also per-AI if I recall, so if the cap is at 2,000 for one of the two AI players (the one that keeps reinforcing there, say), then that could be causing border aggression from it while the other AI only has something like 1,000 ships there and isn't doing border aggression.  Since there are two AIs with their own individual ship caps, that sort of thing is likely to be able to happen, though I'm speaking from memory here.

In all honesty, there are enough complex interworking parts to the AI that, like any good emergent system, it's not always 100% clear why it does any given thing.  In a lot of respects that's by design, because it would be pretty boring in general (especially for me) if it was an AI that I always knew exactly why it did whatever.  In the case of some of the more subtle and recent rules, like border aggression, I don't recall if that's split by AI player on the ship caps or not (I know that the ship caps themselves definitely are, which is why a 3,000-populated planet could be considered "full" for one AI player, though).

Hope that helps!  If it's still seeming wonky, and there aren't a bunch of mines or something, or all ships of one color coming off there, then do let me know.

[Vinraith]

OK, if border aggression is per-AI-player, and the cap-per-AI is essentially half of the total cap mentioned by the wiki, then that might definitely explain what we're seeing. I recall, I think, that the ships are all of one color. I'll double check that, but if that's the case I think you've nailed it.

Thanks for the clear, detailed explanation!

[x4000]

Awesome -- just let me know.  And my pleasure!