Most diplomacy AI i've seen tend to exhibit suicidal tendencies.

Most AI don't sue for peace to cut their losses when they are clearly losing the war. Especially when they are fighting several fronts. They usually only sue for peace when they have been massacred, which by that time i wouldn't bother with peace as i am rushing to grab their territory before the other AI's grabs it. AI's just don't have any sense of self preservation until it's too late.

Another gripe i have always had is that AI's are incapable of weighing who's the bigger threat and where to focus their armies. Most of the time the AI will focus their attacks on the weaker foes. This is usually me as i usually have the smallest armies (cause i always play on impossible difficulty and can't match the AI in terms of unit production). Unfortunately this is dumb as a lot of times they expend too much energy on me allowing a bigger empire nearby to invade and conquer them. This leads me then to a lose the game as the enemy empire has grown too big for me to handle. In other words i lose, because idiot AI#1 lost to AI#2 and i couldn't expand fast enough to match AI#2. In other words, the game boils down to who can grab the most territories as fast as possible.

An AI with a bit more sense of self preservation would be welcome. AI's should ask for ceasefire treaties when things are getting too hot for them. AI's should also have an awareness of who is the bigger threat on their borders rather than always picking on the weaker neighbours. There should also be options for secretly funding a neigbouring empire so that you can use them as a buffer against a bigger empire.

Yeah, it would be nice if a chain of successful conquests slowed your momentum in the short run (by introducing instability, etc.) rather than increase your momentum, that way the conquerer would sue for peace more often.

I'm only suggesting my solution of a desperate-times-calls-for-desperate-measures script by the AI when it's obvious that their opponent is intent on completely obliterating them.  It may be their strategy to deal a nasty blow in order to make the negotiating table more appealing.

Don't forget vice versa. An AI who's desperate should theoretically consider putting his civilization into hock to buy an army or allies to help out against a stronger enemy.

I want AI who can realistically gauge potential threats so that an enemy who's getting ground down by you can appeal to even ambivalent or moderately unfriendly sides to attack you because you're a bigger threat. I can't think of a game that handles alliances of convenience and balances of power rapidly shifting to accomodate changes in allegiance a la 1700s europe. Combine that with an political relations system strong enough that you have to deal with a few mortal enemies thrown into the mix for the cunning to exploit and the diplomacy system alone could sell the game.

I am all for this idea.

Most AIs don't change plans much when thier situation changes.  I would love to see and AI system where the smaller AI empires stick together a bit more to help protect each other from the big guys.  I like the idea that when it looks hopeless the AI will resort to insane strategys to try and stay alive, all or nothing attacks on your capitol / channeler, giving up half thier remaining empire to a different major power in exchange for an alliance (The half next to the player destroying them), any other off the wall idea to stay alive.

Sammual

This could be a great idea. Though, I can see a few flaws in it, some of which you already addressed. This algorithm would have to be coupled with quite a few more so it's not guaranteed to happen every other time. Used in conjunction with other plans though this would be great.

I used to love playing Rome: Total War as the Romans. Eventually though I stopped playing as the Romans because always in late game the Empire would go into civil war. It was a scripted event to follow history. After the first few times this made playing as the Romans late game for me very tedious and as a result my favorite faction became the Seleucids.

I only mention that to show that events that happen every time can make a game predictable and tedious. Sometimes I feel those "easy win" late game battles where you mop up the remaining enemy empire is kind of a reward for fighting the harder battles and gaining supremacy, though they too can get tedious at times so your idea has a lot of merit. I would just like to see it applied with other strategies as well.

I like the last point, Martok.  There could be multiple other ways in which a collapsing AI might select desperate options--- if there were such a thing as "political capital" or "diplomatic capital" they might cash it all in at once in an attempt to gain allies.  Perhaps rather than simply getting a bunch of new allies to go to war with you, they might instead create a "detterance coalition."  Instead of declaring war right off the bat, they might state to the aggresser, "Should you not make peace with our new ally, Kingdom X, we will enter the war on Kingdom X's behalf."  Hm... actually sounds like a topic for a new thread  

He! he! nice idea. Cede territories bordering enemies to a bigger empire in exchange for alliance/friendship etc.

Now that should put a kinker in anyones plans for world conquest.

Boy if the AI did that to me while i was halfway conquering them, i would be real pissed off.