Poor lighting, precipitation, and fog reduce visibility. An area, and creatures and objects within it, can be partially, heavily, or totally obscured.

• Partially Obscured:
  Rain, light snow, fog, and shadows all partially obscure an area. Everything in a partially obscured area is visible, but observers cannot make out fine detail.

• Heavily Obscured:
  Heavy rain, snow, and thick fog all heavily obscure an area. Everything in such areas is faintly visible.

• Totally Obscured:
  Creatures and objects in totally obscured areas cannot be seen, because they are in darkness or blinding conditions, such as a whiteout in a blizzard.