What do you see? Hiding what is not in sight
(Idea thanks to MadKeithV). Our moderator made a point about putting the character down the bottom of the screen and having the world rotate around them. I was quick to dismiss the idea, as an Isometric world (such as what we were discussing at the time) would become distorted. Due to the reality that isometric was out, top-down views were still in the picture. Basically, the world rotates around the character so that the player is never allowed to see behind them. I think that if this were done correctly, then the results would be extremely good and would benefit the sneaky attacker. This would be harder to implement, but it would simulate more about how the player cannot see behind themselves.
Another version of this that was suggested was to rotate the character around the screen depending on which way they were facing. If the character stops moving then the screen centres on them and the player can then see around their character.
Player sight; adding fog, decreasing the light, or blurring
I was thinking recently about what the player would see from an isometric viewpoint that was just out of his character's sight. Would this distort the player's view more as they observed further and further around their character? This idea involves a zoom function that allows the player to view their character from different distances. This allows for obvious landmarks to be seen from a distance, but not so clearly as to distinguish enemies or items. In truth, we can all see about 12 miles to the horizon, but we can not see in detail at that distance. This would be very interesting to insert into a game.
Paul Cunningham suggested that as a player saw further, the more mosaic-like their vision became. That is a simplified version of what is explained. If you were to have a general field of view in which your usual graphics were shown, then you would have a basic top-down square tile view. You then zoom out of that region. The tiles that you had before are the same resolution and the new tiles appear blocky or more pixelated. This continues as your zoom out until your vision suffers so much that you can see nothing. There are things that need to be addressed in this, such as limitation. A player may use a loophole in the system to spy out towns just by looking for large shapes of colour. This is why I still think that the fog of war effect should be used. You can only see what is immediately around your character, and anything that is out of their vision is then unseeable. This can be done with fading, as it often is.