This is about the Essence AI.
If I capture the AI's last castle and the AI thinks my army is stronger, it will not try fight me and the 7 day limit will run out eliminating the AI.
Sometimes the AI will try to capture a different castle away from my best hero
![smile :)](/forums/images/smilies/smile9.gif)
, but usually the AI has a really strong army that could inflict massive casualties on me even if they lose, but they don't fight, the time expires, and they disappear.
I think if a human player was in a losing situation, they would at least attack with their best hero and cause carnage before being eliminated. They might even win the combat.
The combat AI is solid, but it still makes questionable moves like targeting a unit that is not as dangerous as another unit, errors in the way they move their troops, or choosing the best spell to use in a certain situation.