If the user attempts to click to move using the right mouse button to an area that is impassable in the Fog of War (FOW), the game will not allow the unit to move there. This allows the user to figure out where all impassable terrain is by trying to move to it. If there is an ocean or mountain range in the fog of war, the command to move the unit will not occur.

The game should not give hints about what terrain is shrouded within the FOW; all FOW should be passable until the user discovers it. Here is a series of pictures to explain:

http://imgur.com/kOOGJ.jpg

In this picture I attempt to right click to move to an area in FOW. It will not permit me to move there, even though i have no idea what is currently there.

http://www.screencast.com/t/6THtAsDkF

I can click to move in the above screenshot though, even if it is within FOW. The terrain under that FOW is passable

http://www.screencast.com/t/mQfsuQuSz7

I move up to the terrain i couldn't click to, and it turns out to be water. The game should not give me hits about what lies under the Fog of War.