Actually the return as raider one has merits. Id imagine that it depend on both the kidnapping faction and the pawn's traits. So like if a pawn with the bloodlust trait gets kidnapped by pirates there's a fair chance they will join because their motives align. Or if a pawn with greedy or jealous gets kidnapped by say the empire they have a high chance to join because, one, ♥♥♥♥♥♥♥ with the empire is a horrible idea, and two, they get better living and stuff. So yes this would be cool.

Them returning as raiders has been a vanilla function since at least 1.3, they also retain all their implants, it just swaps their gear with whatever faction they then belong to. Means your fully augmented bionic super soldier might return with throwing rocks if hes kidnapped by tribals.

Originally posted by heybroyo64:

But if they simply cannot escape or find themselves back in a raid there could be a quest that reveals their location giving us a chance to get them back by force.

true, but also what if there where also tests that use more skills, but lower level? For example (assume currently it checks if a skill is at least 10)
1. A new one that needs at least 6 shooting and six melee
2 one that needs 6 in both intellectual and social.
That way, they need lower numbers, but more. Also, perhaps others like “at least 6 plants or animals, and at least 4 melee”, the idea being that they are working in farms, which are outside…

Then, even if they don’t pass the tests, there could be, say,a low chance of them just manageing to escape (both from a faction base (very rare) or a caravan (rare)

And, perhaps the tests vary. For instance, the empire probally has ways to inhibit farskip, meaning it takes longer to happen (but intellect +farskip helps there). Pirates are more violent, so the melee/ shooting requirements are higher.
Certain ideologies might change things. For instance, slow research means scientific knowledge isn’t as important, so intellect tests go down. Child labor being encouraged might make it easier for a child to escape, but they are more likely to come back injured.

Finally, perhaps they can “get sold around” as slaves (if the faction has any valid trade partners), or sent as a gift (say the civil outlanders send the pawn to the pirates as a gift to lower tensions)

1. If an allied faction gets them, they will return him to you
2. If a non-hostile faction gets them, then trade caravans have a chance of having the kidnapped pawn as an option to buy, and the same with trading at their faction bases
3. If a hostile faction gets him, certain things are rolled, the idea being each place he goes is easier or harder to escape from.

Originally posted by heybroyo64:

Also It might be funny if we get small messages about them such as "[Faction] is using [colonist] as a blood farm" or "[colonist]'s right lung was harvested by [Faction]" never actually killing them but reminding us that they exist and we're not the only ones doing severely unethical crimes to prisoners.

Oh, and if there is compat with mods like Usankas Biological Warfare… oh, the possibilities…