Bonjour everyone, its the French Paradox speaking! For those who dont know me, Ive joined the Stellaris team this December after a year and a half as a programmer on Europa Universalis IV. Today, we are gonna talk about AI.
A good introduction for those new to the field

Fifty Shades of AI

There are several AI modules in Stellaris. For historical reasons we call them ministers as each one is supposed to handle a specific role in an AI empire. There are 3 broad kinds:

• The AI foreign minister handles diplomacy, federations, galactic community, peace deals and the like
• The AI interior minister is in charge of the economy. He keeps budgets and order constructions, both civil and military.
• The AI military minister is in command of all troops and military fleets, and also responsible for laying out strategic plans when at war.

For each of those ministries there are different ministers there are several options that can be selected for every empire in the game. All of those have generic one which behaves more or less like wed expect a player to and is used for most AI empires. Then we have a bunch of specialized ones for special tags such as space monsters, fallen empires, crisis, marauders and the like. As almost everything in our games, AI is configurable in script for our modders, although Im not exactly sure what would happen if you assigned a space monster military AI to the caravaneers ;) In guise of a welcoming gift when I joined the team, I was tasked with reworking the military one...

The Military AI

To give you a little bit of background, there were several generations of military AIs in Stellaris. The generic one (used by most classic empires) was redone by the great @sidestep last year, while the more specialized ones (crisis, space monsters) have kept close to what they were on release. In the midst of the sad and dark swedish winter, I managed to bring some improvements that Ill showcase today. First of all, I worked on visualization to help us debug how the AI thinks. Funny thing is, it already made it look better to audiences even if it didnt actually change any behaviour. Its actually something thats been observed in video games: a good AI tells you what it does, which makes it look smarter. One of my favourite examples of that would be the enemies in FEAR. So by typing 'debug_ai' in the console and observing an AI empire, you can see what it has in mind:
I don't even see the code. All I see is blonde, brunette, redhead. Hey uh, you want a drink? As a simple analogy, imagine that the AI has a war minister that looks at the big picture and rates every potential target, a general staff who assign fleets to some of those objectives, and then admirals who try to lead those fleets on a tactical level to achieve those objectives... Wanna read more about the AI rework? Check out the full post in our forum here!