AI Diplomacy model

[DaveV]

Per,

One of the best diplomacy models I've encountered was the one in Master of Orion. Each AI had a "relationship modifier" number, which ranged from -100 to +100. When you made an offer to the AI, it would add in the modifier before evaluating the offer. So you could make a lower offer to an AI with which you had good relations than an AI with which relations were poor. Some requests required that relations be above a certain threshold (>25 for non-aggression pact, >75 for alliance). Diplomatic actions would impact the relationship modifier either positively (trading, tribute, non-agression pact, hurting AIs hostile to this AI) or negatively (espionage, massing units on borders, killing the AI's units, being "too far ahead" in the game).

Each race had an agenda for expansion (expansionist, perfectionist), research (military, production, science, trade), and diplomacy (pacifisitic, xenophobic, erratic). They had a 60% chance of using their default agendas; otherwise, they would randomly use another. This meant you could usually (but not always!) count on a given race to act a certain way.

The in-game feel was remarkably human-like. Good AI relationships could be built up over time, betrayals were remembered, the AI seemed to have a genuine personality. I agree that the AI should make the game more fun; I think it can do that best by simulating as closely as possibly the way good human players play the game. I also agree it would be boring to have all the AIs aim for spaceship victories; the best games have a mix of warmonger and builder AIs.

[Sonic]

I agree with gold cost theory, but treaties seems to be not good.

In my opinion every empire should have it's "worth". Military worth of a country should be counted by counting all the military units (and giving worth point for each units, obviously differing per unit), countrie's ability to build new units (probably by some "avarage units per turn, if producing them in every city" rating or just number of shields), unit placement (the nearer they are to border of AI country, the more points they would add to worth rating), economy (city improvements, especially military ones), treaties (each war the country has would bring the rating down by a certain percent of worth points the country fighting against subject country has. Peace would neither add neither remove anything, while Alliances would add up to total), budget (certain number of points per each gold unit), infrastructure (ability to move troops quickly around a country), etc. And AI would be able to have much more than one enemy, just jointly amount of all enemies worth rating could not surpass certain percent of AI's empire worth rating. That number could be randomly set before each game. Some AI empires would get only 50% rating thus they would be peaceful, others would get maybe even 100% or 120% rating, thus they would be bullies, sometimes even going on suicide.