I'm just saying that a different pathfinder might be able to pass trough there.. Collision with a moving unit would still be a problem.. One of the unit should stop for a while, the other will find a new path, maybe reserve some terrain for the next few moments and then the other unit will find a new path... And shroud of war would be considered as a free space, or not? When an unit collides with an obstaclee that wasnt there before, would it try to find a new path or follow the old one?