Darkvision

Many creatures in fantasy gaming worlds, especially those that dwell underground, have darkvision. Within a specified range, a creature with darkvision can see in Dim Light as if it were Bright Light and in Darkness as if it were Dim Light, so areas of Darkness are only Lightly Obscured as far as that creature is concerned. However, the creature can't discern color in that darkness, only shades of gray.