What determines unit non-war movement?

[planetfall]

I had assumed it was a combination of having Early Empire and unit with false ZOC. But that is not it. Settlers, missionaries, archaeologists all have ZOC as false, but only archaeologists can enter AI empire without triggering war challenge. So what determines this ability?

 

[vorlon_mi]

IIRC, missionaries/apostles/gurus can all move across borders just fine, regardless of the state of war/peace. If you're at war with the civ, your religious units are vulnerable to being squashed with "Denounce heretic", but they can cross the border. Same for archaeologists. Settlers or builders, not so much.

No, I don't know which flag governs the behavior.

 

[planetfall]

it was just a mod, and all is well after removing mod