game turns

There are no set turn limits, the game continues until any of the selected victory conditions are achieved.

There are four victory conditions,
Military, Research, Alliance and Influence. Only Military victory is obligatory the other three are optional.

Hi!

AFAIK there's fixed game lenght of ~200 game years, or ~10000 turns. Don't worry about that: you'd need to actively play the game for 166 hours, if you'd use for each turn only one minute.

BT, Iztok

Thanks for clearing that up Iztok, You learn summit new and that.
More accurately then, there are no realistic limits unless you're an obsessive/compulsive and I wouldn't wish that on anyone.

Does the AI actually try to win, or are they just there to annoy you?

Depends on what difficulty level your playing on. I mean the AI doesn't really start getting decent until you hit the tough level. (1.4x) Not sure if this has changed as of yet with DA or newer versions of DL.

Once you learn how not to beat yourself you should jack up your playing level. Make no mistake about it. The AI at higher levels will hunt you down, kill you and your entire race, and use your bones as ship jewelry.

DL v1.5.080
I couldn't agree more. The AI is annoying at the starting diff lvls but as you work your way up the names they gave the diff lvls become apparent - Tough,Painfull,Crippling,Masochistic,obscene and Suicidal all speak for themselves     

Those names weren't picked at random. Give yourself a culture shock king, If you're realy new to the game select suicidal and see how long you live, Trust me it's fun.

P.S. you'll be swearing at a machine like it's shagged you're misses.