(Passive) [Familiar] WIS
  Possessed By: Some Humans, Barbarians, Monks, Rangers, Rogues, Warriors, Assassins, Earthsingers, Master Archers, Sentinels, Shadowdancers, Tattoo Mystics, Twilight Huntsmen, Underdark Warriors, Guardian priests.
  Effects:  The Spot skill has these practical applications:
   * Discern Hiding Creatures (Passive): The Spot skill is used to perceive creatures that are using the Hide in Shadows skill, as described under Hide in Shadows.
   * Spot Invisible Creatures (Passive): A DC 20 Spot skill test is used to discern the slight shimmering effect around an invisible creature, as described in the writeup of the invisibility spell.
   * Setup Watches (Passive): The Spot skill is also used to arrange and undertake watches when a character rests in the dungeon at night with companions. The character must have at least one companion who is not a mindless undead or a summoned creature with a summoning duration of less than a full day to use this function.
   Each character in the group takes an equal portion of the night to watch over the others, ensuring their safe rest. The total of all the Spot scores in the group is taken, and that total is subtracted from the percentile chance the player's group has of having an encounter during that rest period. (It's assumed that monster groups that ambush the party at night are looking for an easy victory, and can be held at bay with sufficient vigilance.)
   Additionally, if the total of the group's Spot scores exceeds three times the current Depth of the dungeon, the group is guaranteed to gain forewarning of any encounter even if one does occur -- the members of the group will all be awake, and will not suffer a delay in acting at the beginning of the encounter. This is especially important, since it prevents monsters from being able to perform a Coup de Grace on the player character or her allies.