Search. You might want to search for a hidden object, a secret door, or a hidden foe.

Depending on the nature of your search, the GM might have you make a:

 

See here for difference on the two.

During a combat round, your effort may require the Search action. Or not.

Is your search a success?

 

  • If you try to discover a hiding enemy, your Wisdom (Perception) check is contested by the enemy's Dexterity (Stealth) check. Go here for details on hiding. ​

Whether an area is lightly or heavily obscured is an important factor in the success of a search.