Check: The Spot skill is used to notice items that aren’t immediately obvious and people who are attempting to hide. The GM may call for a Spot check by a character who is in a position to notice something. A character can also make a Spot check voluntarily if he or she wants to try to notice something in his or her vicinity.

Spot is often used to notice a person or creature hiding from view, detect secret doors, hidden structures or concealed items.

Spot ambush14
Spot hidden structure or secret door15
Spot concealed item15