Here is a map way in the mid game that should support the AI but they all end up in the same situation which I have seen in almost all of the game: They are barely vegetating:
https://www.dropbox.com/s/t69ttmb0k0luon4/Haduir%20First.rar?dl=0
The map is medium large, not too crowded with the recommended amount of AI empires, close systems, and the human player remained so friendly with its enemies that he not only didn't attack them, he attacked the Marauder bases around him to help them out. I also signed any treaty they offered and gave them anything they requested (food, money)
Despite this you can observe how poorly all of the enemy AI empires are doing. The only one which is kinda of ok economically has 1 ships. Though it is waging war with two other empires, they are insignificant compared to its raw economic and population numbers (probably also tech as we are talking about the Orthin here).
So why does it always end like this? From what I have seen there are 3 main reasons:
1. Marauders cut down the AI empires hard due to their: sheer number of bases where they spam, tech, aggressiveness
2. Somewhat tied to the above: Marauders AVOID player space as they can be easily bribed
3. AI does not seem to be able to amass considerable fleets to begin with and combat this threat. You can see on the Yoral that they are pretty much protected by my empire from all sides, still they were unable to build up anything that resembles a strike fleet
To solve the above the simplest solutions seem simple:
1. Have the AI buy their way out from Marauder attacks if they can afford it and do not have the strength to resists. To control that this is working, diplomacy screen should show next to the Marauder faction, who or how many empires are paying them off
2. Slightly increase pay-off value for Marauders and fix the bug where it seems that human player only needs to pay once for the protection
3. Reduce strength of Marauders, making it dependent on the number of empires that are paying tribute to them. If they are paid off by 3 empires already, it should cost more for the next empire to pay them off. Thus they can scale with the empires around them but not be an outright empire killer
4. Have the Marauders fights for money so the AIs can send them against each other as "mercenary" force. As they clearly have the tech and numbers, they can effectively supplement the lacking AI fleets if the AI has the funds
5. Teach the AI to conserve ships (retreat if no chance to win - this is already working in a lot of cases) and build fleets - this is probably the most difficult task which deserves its own study but should be a mid-term goal
Another are where the AI can be improved is to gear it towards utilizing race-specific advantages.
e.g.: When fighting a well fed Ashdar Imperials Empire (fed up for over 100 turns and not Marauders), they did not seem to utilize the Stargate which could have been used to propel a fleet directly into the heart of my empire.
A quick and probably easy fix short term would be two map settings:
- Marauder base frequency (they are way to cool to turn off pud reduced occurrence helps the AI)
- Marauder aggressiveness