AI science ships traveling into my systems

[Bryan=0101]

Borders are closed, they've just flown in a science ship into my system, i cannot shoot at it because that'll require war.

The border sure doesn't seem very closed.
edit: added screenshot

https://steamcommunity.com/sharedfiles/filedetails/?id=1766792481

[tempest.of.emptiness]

Do you have a truce with them? Borders are forced open during a truce.

[Zorlond]

Could be another empire's, one that you haven't closed borders to. They could have come from the far side of the galaxy, if enough borders are open to them.

[Bryan=0101]

It's a a small single planet "republic" that I do not have open borders with. If it makes any different they were once rebels but i conquered and destroyed the empire they were rebelling from.

I do have a claim on their world tho, not sure if that makes any difference. I haven't gone to war with them, so i got no truce.

My current save has no mods.

[Bryan=0101]

https://steamcommunity.com/sharedfiles/filedetails/?id=1766792481

[Tseudonym]

Originally posted by 101=5,Bryan=5:

https://steamcommunity.com/sharedfiles/filedetails/?id=1766792481

By the looks of that image they're in an unclaimed system.

[Bryan=0101]

Originally posted by ProDude:

Originally posted by 101=5,Bryan=5:

https://steamcommunity.com/sharedfiles/filedetails/?id=1766792481

By the looks of that image they're in an unclaimed system.

The red tint is my territory, it is several systems deep into my empire.

Even if that star wasn't claimed, they passed through 2 systems with planets I control that have the FTL blocker thingy on their respective stations which even makes me question this even more.

[Erulogos]

Wiki says: Experimental Subspace Navigation
The Speculative Hyperlane Breaching technology enables science ships led by a scientist Leader to travel directly to a destination, ignoring the hyperlane network. During the transit the ship is considered MIA. Experimental Subspace Navigation can be used to bypass impassable areas such as a guarded system, a closed empire's borders or the galactic core.
Thats probably it assuming that the AI can use it

[Bryan=0101]

Originally posted by Erulogos:

Wiki says: Experimental Subspace Navigation
The Speculative Hyperlane Breaching technology enables science ships led by a scientist Leader to travel directly to a destination, ignoring the hyperlane network. During the transit the ship is considered MIA. Experimental Subspace Navigation can be used to bypass impassable areas such as a guarded system, a closed empire's borders or the galactic core.
Thats probably it assuming that the AI can use it

Well, it sounds like it's time for another purge.

[tempest.of.emptiness]

Originally posted by Erulogos:

Thats probably it assuming that the AI can use it

Experimental Subspace Navigation doesn't allow science vessels to jump into the territory of another empire that has closed borders to them. It can allow the vessel to bypass a closed empire's borders by jumping to the far side of that empire (ie jumping over the wall), but it won't let them actual go into or through systems they control. So while the AI can use ESN, ESN won't explain what has happened in this case.

Originally posted by 101=5,Bryan=5:

https://steamcommunity.com/sharedfiles/filedetails/?id=1766792481

I can see from your screenshot that you have closed borders with the owner of the science vessel (Free Xeltek Sovereignty). However, I can also see that you are at war with another empire, and that empire is the overlord of the FXS.

My guess is that your enemy became the overlord of FXS after the war had started. This created a situation where your borders were forced open to them (because their overlord is at war with you) without actually putting you into a state of war with each other (presumably because that state change occurs only at the start of the war, which might be a bug). If I am correct, then even though your borders are officially closed they are able to move through your territory (and you through theirs). That state would last at least until the war is over, and then possibly also for the duration of the truce after the war.

[Radiosity]

Originally posted by tempest.of.emptiness:

Originally posted by Erulogos:

Thats probably it assuming that the AI can use it

Experimental Subspace Navigation doesn't allow science vessels to jump into the territory of another empire that has closed borders to them. It can allow the vessel to bypass a closed empire's borders by jumping to the far side of that empire (ie jumping over the wall), but it won't let them actual go into or through systems they control. So while the AI can use ESN, ESN won't explain what has happened in this case.

Originally posted by 101=5,Bryan=5:

https://steamcommunity.com/sharedfiles/filedetails/?id=1766792481

I can see from your screenshot that you have closed borders with the owner of the science vessel (Free Xeltek Sovereignty). However, I can also see that you are at war with another empire, and that empire is the overlord of the FXS.

My guess is that your enemy became the overlord of FXS after the war had started. This created a situation where your borders were forced open to them (because their overlord is at war with you) without actually putting you into a state of war with each other (presumably because that state change occurs only at the start of the war, which might be a bug). If I am correct, then even though your borders are officially closed they are able to move through your territory (and you through theirs). That state would last at least until the war is over, and then possibly also for the duration of the truce after the war.

Correct. A vassal is automatically dragged into a war if the overlord declares war or has war declared on them.