Quote Originally Posted by Ar7
I have been lucky enough once. I was defending against the Gauls, my army was two times smaller, but the terrain was perfect for a massacre. I placed my men on a flat piece of land right between two huge forests. The infrantry line was holding their position between these forests and a unit of equites was in each part of the woods. As soon as the gauls made initial contact the cavalry came and the Gauls started to route asap This battle ended with myself suffering 30 losses and the Gauls loosing around 1200 men , considering that my starting army was around 600 against 1300 it was a perfect victory.

So I guess it all comes down to luck, whether you get that perfect terrain or not.
Cool, but I think he was talking about strategical ambushes (which are supposed to be like the Teutoburger Wald historical scenario), not just tactical ambushes. Myself I have never been able to ambush an AI army on the campaign map, nor have I ever been ambushed, which is a shame since it sounds like so much fun!