Fog of war refers to the obscuring effect that takes place on areas of the map that are not within the vision range of your allies. This means that, while you can see the topography of any area on the map, you can only see enemy units located near allied units or your champion. Take note of the areas surrounding your allies. Notice that these areas are brighter. These brighter areas are within the sight range of your champion or one of your allied units. Also notice that the rest of the map is somewhat shrouded. These shaded regions are covered by the fog of war. Enemies in these shaded regions cannot be seen until they enter the sight range of one of your allies. When enemies enter the sight range of an allied unit, they will be revealed, unless they are able to turn invisible or they are hiding within brush.