Lord Parkin
aka emperor
Not 100% sure on this, but I believe the AI considers the value of siege units and uses them first if necessary. After that, I think the unit with the highest odds attacks first. After each attack, the AI reconsiders the situation and decides whether it is worth attacking again. If so, it attacks with the unit with the next highest odds, and so on. It's been a long time since I've had a stack (or especially a city) attacked by an AI though, so I can't confirm this.1.) Does the AI use auto attack when attacking. for example, if the AI were a human player, do they simply take a stack and right click on an enemy city until it is taken or their force is destroyed, or do they at times use more subtle methods that a human would, like attacking first with a weak unit and then following up with a strong unit for a confirmed kill?
I think suggesting the AI "uses more subtle methods than a human would" is absurd, though. A good human player can always out-play the AI in terms of military strategy, regardless of difficulty. That's part of the reason I enjoy playing multiplayer games so much, since you have much tougher competition.
