Hi Michael,Was the unit that attacked you a ranged unit of some kind? It is possible through range to attack diagonal. So, say, with you being 2 spaces diagonally away from your enemy, if the enemy had a range of 4 or more, it would be able to attack you, since its attack would go 2 across and 2 up. It takes more range to go diagonal though, for that reason. But hopefully this explains that sort of thing a little better.
Craig