is it just me

[flavian]

or once you have about 20 cities, is it impossible to be beaten, even on deity? i've never been totally conquered. computer just can't attack on such scale, even when it has enough units....

 

[Nylan]

Maybe its just the way the AI thinks. Im sure they could do it of the world allied against you or if you cant take back the cities they take from you.

 

[Terrapin]

I do not think it is possible to be conquered by the AI except very early in the game. As you say, the AI does not 'think' strategically at all.