Ie. what amont of bribes does anything? does the AI consider total sent or how much you send each time ie. can I send a little every turn, or do I have to sand large sums at once? How does attitude influence things, are there points of no return (ie. at hatred no amount of bribes does anything).

unfortunately googling "warlords 3 diplomacy" doesn't give any results these days...

My understanding and what I've gathered from the manual and some old guides online is this:

The AI has a hatred scale from 0 to 100 (least to most). The more hatred, the more likely they go to war with you. The less hatred, the more likely they ally with you. In a standard game each AI has a random hatred value of around 1-10, and it scales up as the game progresses. I don't know what events raise this, other than war, razing, and treachery.

Every 50 gold you send to an AI reduces the hatred score by 1 point. I don't think it matters how often you send it or how much at once. All I could find is a flat 50 gold per 1 point.

My rule of thumb for making new allies is that it basically only happens when they "Trust" you, and often not even then. I've had an AI accept an alliance at "Friendship" once, and I've played many, many games, so that is rare enough to fall into the category of "Technically possible". Any lower than that, and I haven't seen an AI accept an alliance offer.

I generally don't bother with bribes. Once their opinion of you drops, I think your money is better spent on improving your condition, not trying to get an AI to ally with you.

But I can't seem to keep the opinion from dropping super fast? From my observation occupying a city close to their city or even them occupying a city close to yours seems to drop the opinion beyond repair. The same if you're just doing good. I guess what you need is some sort of list of how different actions (not just bribe) affect your standing with AI?

I am playing the campaign and the reason I'm interested in alliances is more flavour/RP than strictly finding optimal ways to play. Until now I have failed all my attempts at allying with any side I start with Trust, even after sending them thousands of gold. It just doesn't make sense that I'm just murdering everyone as supposedly a "good guy" and it is ruining my immersion tbh and makes me not want to play as taking part in a story is a huge part of the fun when playing campaigns. I really love the little environmental storytelling that is going on here with descriptions of every city and ruin, but I want the gameplay to support that a bit.

The briefings themselves imply alliances. For example the 6th scenario of RoH campaign mentions that you have to either "repel or ally" the various barbarian tribes. Most of them start with trust. The 3rd scenario is clearly set up in a way that implies you should take the side of the rebelious Selentine Princess (Trust) in civil war against the Selentine Emperor (anger). In the 5th scenario I had to ruthlessly butcher the supposedly "peaceful" elves living in the enclave in the middle lol. The 4th scenario mentions explicitly helping the elves to supposedly meet with their chief.

Maybe in order to ally I have to slow down my expansion until I after I ally, but how am I going to get the gold I need to make them ally? Not to mention that if THEY decide to occupy a city that's close they will declare war soon after. Will it happen if I just wait a bit? But what then, if I'm so weak due to not expanding. The upkeep itself is going to kill me. I can play a bit suboptimaly for RP sake, but this is ridiculous.

And I vaguely remember succeeding in making alliances in my 90s memories. Maybe because I was so bad at the game back then that the AI didn't consider me a threat lol.

I will experiment with limiting my expansion. Maybe it'll add a little difficulty because otherwise the RoH campaign seems fairly easy even if you lose a hero or two. I just wish I knew if it's doable at all.

Those are the sorts of things that would start conflict between human players too, I would think. When borders rub up against each other or if someone starts getting powerful, war is more likely. In a number of cases it is pretty random whether you'll be able to ally with someone else or not. I've generally had success allying with the Elenian Knights (green) in the second map when you are uniting the orders of knighthood. Occasionally I think I've gotten an alliance with Theira or Gildines, but I can't recall a time I've allied with the Bartonians.

Several of the maps have random starting dispositions; I've allied with the Selentine Empire before in Map 3, eliminating The Princess on my way to victory. Plains of Ar and the one with all the barbarian tribes are both huge crap shoots on whether someone will ally, as well as who. To help illustrate, I've had someone decide to ally (or not decide to ally) when I reloaded a save during the very same play through of a map for one reason or another (for example, the Forest Tribe decides to accept my alliance, but then I reload to the previous turn, end turn, and they didn't accept this time).

If it helps your RP, you aren't quite the "good guy" here. This is a campaign of war, survival, and revenge, stopping Bane before he rolls over everything. If these other factions won't join you willingly, then they'll have to be brought to heel so you can continue the war against Bane. Most of the maps can end early with the other factions surrendering to you as long as Bane and Sartek are dead; you don't usually have to engage in complete annihlation, you just need a very decisive number of cities after Bane and Sartek have been eliminated. If you don't have decisive control of the area for each map, then you can't keep your supply lines safe, etc.

Some maps do have you start with allies (like the Dwarven Mines). Maybe the elves were too spooked about all the invaders to be willing to place nice with your particular faction of strangers?

I can help you with that, straight from the Prima guide: You can only ally at a Hatred value of 0 or less. You also have to be 'eligible' for an alliance, which, in campaign scenarios, is pre-determined by the designer. In random scenarios, it's random.

The Warlords games weren't really designed with peaceful coexistence in mind, but this should give you a few pointers on how to get and keep alliances:

1) Don't commit treachery on anyone or raze anything.
2) Have an enemy between yourself and your ally. If you're neighbors, you'll need frequent bribes.
3) Don't be too powerful compared to your ally. Don't have many more heroes and armies.
4) Don't completely wipe out factions until you're ready to finish the scenario. Keep in mind that computer players will also try to wipe out players with fewer than three cities.

Thanks guys, these last posts were super helpful! Interesting point about that "spheres of influence", and I actually had a hunch that something like that must be going on. Feels cool to have it confirmed. I think the descriptions of cities give hints about which city belongs to which player in campaign?

Also, I recently noticed that capital cities of factions are marked even if someone else owns it - the list above doesn't mention it, but do they hold any diplomatic significance?

As for the randomisation aspect, indeed, I just restarted the scenario with barbarians and noticed the diplomatic relations are all different (except Bane of course).

Unfortunately I didn't succeed in allying anyone. I aimed for Sun Tribe and the Forest Tribe because they were farthest away from me. But Sun Tribe gets wiped out and Forest Tribe drops from friendship to anger in a matter of a few turns the moment they get cities close to mine. Though I guess owning cities of the 'expired' players tilted the scale - even though it wasn't me who wiped them out. But in this scenario war with everyone isn't jarring at all compared to previous ones - those are "fickle barbarians" after all.

It might also be why the Princess declared war on me in the Selentine scenario, as it happened right after the yellow faction (forgot its name) got wiped out and I owned most of its cities.

But it's very difficult to limit getting powerful too fast and it's often too fast to compensate with bribes and you're exposing your flanks by not wiping out enemies.

The linear relationship between power and hatred generated seems also kind of silly, I'd say that at a certain point it's a more optimal decision for the faction to ally with me if I give them that option, because they have no chance to beat me and them hating me is simply a death warrant. It might make sense for certain factions to fight to the last man (like Bane or Sartek) but not so much for others.

I also wonder what makes the factions surrender, because in the Selentine game they only surrendered with one city left and I had a boring half hour of having to conquer the rest of the map after I obviously won, and in another they surrendered when I owned only 1/3 of the map and it actually surprised me.

It would have been super fun if the game had the option to give cities to other players and even resurrect dead factions like in Civilisation. That's probably the main thing I'd add to this game to make it better (for me). I'd also make the spheres of influence and the exact reasons and value of hatred visible. I would also subtract hatred for having common foes. I wonder if it's possible to mod for such an old game.

I think the AI en-masse surrender occurs at some point when the power difference between you and everyone else combined reaches some given threshold. I'm really unclear on how that power differential is determined, though. I think a lot of it depends on how many cities you have and the power of your armies (considering quality AND quantity) compared to the remaining players. I also assume you have to be overwhelming compared to everyone else put together, not individually.

Of course, there is no surrender option if Bane or Sartek are still alive, regardless of the comparative power difference.

yeah, that seems to be how it is intended to work, but in one mission they surrendered only when they had one city and I had the whole map lol. And most missions I had to own almost every single city. Actually, there was only one mission, the one I mentioned above, where it seemed to work as intended (and that was the one mission where you don't really need to kill Bane and Sartek - Bane was alive and kicking)

one last thing - is it possible the AI willingness to Ally is affected by difficulty? Cause I'm playing on Expert. Maybe the difficulty disables alliances to make it harder?

I haven't the faintest idea. :)