Stumped on why no capitulation

[D64]

Usually I can figure out why an AI won't capitulate to me, but this one has me stumped.

My enemy is Joao II.
We are on the same land mass.
I've taken 13 of his 21 cities, including two different capitals; my total land is at least 3 if not 4 times his.
I'm not at war with anyone else except his tiny colony vassal (3 cities); he's not at war with anyone else.
I've lost maybe 20 units to his... 80? At least that. I have the edge in war tech.

It just seems like he should've given up a while ago now. "We're doing fine on our own," is what he says.

 

[lymond]

I think it is probably the vassal. Has it broken free yet? If it has then do a cease-fire with the vassal and he should cap, the immediately declare on the old vassal. His resist cap ratio is on the lower end, but AIs will vassals will be nye impossible until the vassal breaks away, and even then they become afraid of the old vassal (considering that they would immediately join that war if they bend the knee)

So if you are tryomg to vassal an AI that has vassals, consider these things before you go into it:
1) Do not weaken the vassal too much. You might not be able to avoid killing some troops but avoid doing too much damage unless that vassal is in the way regardless and you can just take the whole enchilada quickly so he does not exist.
2) For the master, take some cities but kill his troops. Lower his power. The vassal will break free, but he might not if you are significantly weakening the vassal at the same time.
3) Note if said vassal was a "peace-vassal". If so, they may very well break free very fast after you ...say...take out a couple of the master's cities and decimate his stack. A colony vassal is a bit special though, but I believe they can break.

 

[D64]

I think it is probably the vassal. Has it broken free yet? If it has then do a cease-fire with the vassal and he should cap, the immediately declare on the old vassal. His resist cap ratio is on the lower end, but AIs will vassals will be nye impossible until the vassal breaks away, and even then they become afraid of the old vassal (considering that they would immediately join that war if they bend the knee)

So if you are tryomg to vassal an AI that has vassals, consider these things before you go into it:
1) Do not weaken the vassal too much. You might not be able to avoid killing some troops but avoid doing too much damage unless that vassal is in the way regardless and you can just take the whole enchilada quickly so he does not exist.
2) For the master, take some cities but kill his troops. Lower his power. The vassal will break free, but he might not if you are significantly weakening the vassal at the same time.
3) Note if said vassal was a "peace-vassal". If so, they may very well break free very fast after you ...say...take out a couple of the master's cities and decimate his stack. A colony vassal is a bit special though, but I believe they can break.

Thank you, I'll keep all this in mind.

Does it matter that the colony vassal is restricted to an island?

 

[lymond]

Does it matter that the colony vassal is restricted to an island?

Not sure if I understand the question. A vassal is a vassal.

 

[Plains-Cow]

Thank you, I'll keep all this in mind.

Does it matter that the colony vassal is restricted to an island?

Done this before. It doesn't matter. Either kill the vassal and then Joao will capitulate, or kill Joao enough until the vassal breaks free from being too large compared to the parent (not always guaranteed to work, but then you can just cap the vassal after eliminating Joao). In the thousands of games I have played and watched, I have never seen an AI with a vassal under their belt capitulate, even if they are down to just one city left.