optional rule for hills: canopy

Most terrain is “open topped” some terrain, however, is not. In such cases, terrain may have different “game heights” in regards to what it blocks for LOS and when it will provide cover. Terrain with a roof, for instance, counts as level 3 for cover saves, but may be only level 1 or 2 to block LOS depending on the size of the building. This terrain cannot block LOS regardless of depth to enemies that are higher than its “LOS size”. For instance, a bunker that is level 2 in height has a roof. Enemies that take higher ground cannot ignore the cover save afforded the bunker by taking a position on a level 2 hill, though they can ignore its ability to block their LOS. If the bunker is large, and there is more than 6” between the target and its attacker on the hill, the attacker may still draw line of sight to the enemy as he is shooting down and not horizontally, through the terrain.