I am well on my way to beating a game against 9 AIs on hard, and have followed a rather sneaky strategy for the past 3 hours or so. I managed to do enough missions for everyone that I had a peace treaty or cease fire with all of the AIs when there were 7 left in the game. 2 of the Vasari AIs decided to team up and destroy the other players, so I thought it would be fun to send along a Missionary (I'm Advent) with their fleet to sneak up and occasionally steal a newly bombarded planet out from under them. At first I thought getting two in a row was a fluke, but then it turned out that every time their fleet took out a planet, they would retreat and later send in a colony ship. Since I had mine positioned right there, I was able to take nearly 25 planets this way. Now it is only me and my 2 Vasari allies left, and they are wailing on each other while I follow around with my colony ship. A lot of fun for me but maybe it should be something addressed in future AI revisions. Anyone have other sneaky strategies they would want to share?