I feel like an idiot. I just noticed that units holding ladders during a siege assault can run with them, significantly reducing their vulnerability to missile fire as they approach the walls. I suspect almost everyone already knew this, but I've never seen it mentioned anywhere before. (Probably because it was so obvious - click the run button!)
So, what other 'obvious' features have other people noticed in the game; the things you didn't see until you'd played for a long time, or which are activated with some little-used button that none of us have bothered to click before?
Bookmarks