Requires Training: No.
A successful Spot check reveals a hidden creature.
Check: The DC is determined by the Hide check of the hidden creature.
Special: The Alertness feat grants a +2 bonus on Spot checks. Rangers receive a bonus on Spot checks against their favored enemy. Elves gain a +2 bonus on Spot checks, and half-elves gain a +1 bonus.
Use: Spot is part of the Detect modal action. In Passive Detect mode, checks are made automatically every round. Active Detect mode is a modal action that reduces the normal movement rate and makes the character perform an Active Spot, as well as Search and Listen checks.