As we all know the diplomacy in RTW, MTW and STW have not been especially good. In STW and MTW it was mostly that it was too limited, but in RTW one main problem was/is that the ai doesn't care about such things as alliances, and gladly backstab you even if that, looking at their position, would be the most stupid thing they could possibly do next to disbanding their entire military, and not to mention an inability to realize when they are getting badly defeated, not accepting peace even if there chances of doing anything else but being defeated are next to none.
As an example of more reasonable ai behaviour in regards to diplomacy in a game not to dissimilar from the campaign part of RTW we could look at the old game Legion. Although there are some problems with diplomacy there, namely the fact that ai allies never backstab you or cancel your alliance with them unless you attack someone without first formally declaring war, and that the options available are too limited. The first good thing is that you can see how what relations there are with the other factions, something which is needed, it is always useful to know wether they refuse an alliance because the hate you or if they merely dislike you.
The good things about the diplomatic ai in Legion then? First, although at times declarations of war may seem somewhat random, that is mostly in the beginning where almost everyone goes to war with someone else and the player has yet to become more powerful than most of the opponents. The ai does not go to war if they are already in a war (which the RTW ai does almost all the time), but since the ai actually signs peace from time to time this is in no way a problem (in RTW where peace comes very seldom the ai waiting to get peace before attacking their other neighbors would probably make certain factions rather quiet when it comes to starting wars).
When it comes to making peace the ai in Legion acts rather sensibly. If they are at war on many fronts they do attempt to get peace with as many of them as possible. Similar if they are getting beaten up badly they also tries to get peace rather than be wiped of the map. Also if they have some success in a war, and there is no or little hope of taking anything more at the moment, or just if there isn't anything they really want that their opponent have, they try to get peace. One example of that last one could come from my game with the Frentenians:
As I had conquered most of the former Samnite territory, some additional territory on the eastern coast, as well as the lands that had belonged to the Volscians (as you can guess I was fairly succesful), to my north I had my allies the Romans, and in the south the Lucanians (my allies) and the Calabrians where fighting. Then the Campanians went to war with me, at first glance they did not seem to be able to become any real threat, out of their three starting cities they only had Capua and Neapolis, Nuceria having fallen to the Lucanians. But the Campanians conquered the southernmost of the former Volscian cities, and then asked for peace. I refused. But I was unable to reclaim the city, and an attack I made against Capua also failed miserably. Eventually they also captured Anxur, the northern of the former Volscian cities, and then asked for peace. I refused, and this time i retook the city.
The Campanians stubbornly refuses peace, but since their cities are to welldefended for my army, and they can actually go on the offensive every now and then, so it does make much more sense than when the Egyptians in RTW in my current game with the Seleukids refuses peace, even though all that remains are their Egyptian provinces and they have lost nearly every battle. So while the Campanians in the example still can hope to achieve something more in the war, the Egyptians for whom the best option would be peace and attempt to rebuild their army so they can retake their provinces later and not put their trust in the fact that I don't really want to invade Egypt yet. In that Seleukid game the Armenians fell because of their stubbornness, I mean if your only remaining city is besieged by an army much larger than their garrison and they get offered the extremely generous terms I offered them (for one thing I would give them back the provinces they had had before I invaded them in response of their failed invasions against me) they should have accepted, or atleast come up with a counteroffer.
Now what about ai and the breaking of alliances? Although I don't mind the occasional backstab if there actually is something for the ai to gain, in RTW the ai seems to backstab you everytime it feels bored, as in this example; I, playing Egypt, have among other things taken Athens (from rebels). I am allied with Greek cities who are at war with the Romans who have Epirus, and in peace with Macedon. The Greek cities have a fairly sizeable army in Aetolia (apart from the acceptable garrison). What do you think they do with it?
(alternatives from 'smartest' to most stupid, order of b-e may be discussed)
a) Attacks the Romans who they are already at war with
b) Keeps it there to defend from possible Roman or Macedonian offensives as well as any potential backstabbing Egyptian behaviour.
c) Goes to war with Macedon and invade Thessaly.
d) Waits with army until Macedon and Egypt goes to war (bound to happen eventually) and attack whoever it is most beneficial to strike against, and ally with the other.
e) Allies with Macedon and attack their original ally, the Egyptians, before they get ideas to strengthen their hold in Greece.
f) Attacks their only ally, who BTW is rather strong --> get beaten up and loose Rhodos, possibly more.
Anyone that has played RTW will probably be able to guess the answer rather quickly. In my opinion alliances should probably not be until someone breaks but a set number of turns, how many would be the best I don't know, and allies should try to help each other, and only backstab the other if there is a good reason. It should be noted that the various actions should have effects with regards to your relations with the other factions in reasonable ways (declaring war against one faction should reduce relations with their allies (and neutral factions to a lesser degree) and increase it with those they are at war with (although maybe not by much)).
To sum up what I would like to see:
- Some way to tell relations with other factions
- Ai that actually gives declaring war more thought (or the very least that fights the wars more efficient than currently in RTW)
- Ai that actually tries to get peace when in war on many fronts.
- Ai that atleast can consider peace if they are beaten up badly and have little to no chance to turn the tide, so that they can get time to rebuild
- Ai that tries to get peace if they have gotten what they want from the war (apart from tribute which of course will be demanded if they want it)
- Alliances lasting for a set number of turns
- Allies trying to help eachother if they can
- Ai allies only backstabbing you if they have something to gain from it.
- Diplomatic actions (declaring wars, declaring alliances void, making alliances etc.) should affect relations (they may do it in RTW but who can tell?) with all factions too some degree. Declaring war too soon after peace or on ally should probably affect relations with everyone much worse than just going to war.
