Perception measures your ability to be aware of your environment. Every creature has Perception, which works with and is limited by a creature’s senses.
All player characters and most creatures are proficient in perception. A player character’s proficiency and when that proficiency improves are determined by your class.
Creatures have different types of senses, ranging from normal human senses to fantastic senses like blindsight.
In addition to regular vision (how humans typically see the world), creatures can also have low-light vision, darkvison, and greater darkvision.
A creature with low-light vision can see in dim light as though it were bright light, so it ignores the concealed condition due to dim light. Creatures with low-light vision include elves and gnomes.
A creature with darkvision or greater darkvision can see perfectly well in areas of darkness and dim light, though such vision is in black and white only. Some forms of magical darkness, such as a 4th-level darkness spell, block normal darkvision. Creatures with darkvision include dwarves and goblins.
A creature with greater darkvision, however, can see through even these forms of magical darkness.
Precise, Imprecise, and Vague Senses
A precise sense is one that can be used to perceive the world in nuanced detail, such as normal vision. To target creatures without a penalty, you must locate them with a precise sense.
An imprecise sense is one that cannot detect the full range of detail that a precise sense can. Imprecise senses can detect creatures. Typical human hearing is an imprecise sense. For example: you might hear a zombie shambling around in a dark room.
A vagues sense is one that can alert you that something is there, but which isn’t useful for zeroing in on it to determine exactly what it is. Typical human smell is an imprecise sense. For example: you might smell ash and smoke, but you can’t tell if it’s from a campfire or a fire elemental.
Creatures can have different senses at different degrees of acuity. For example: many animals have Scent as an imprecise sense.
Perception in Combat
Creatures roll Perception for initiative by default.
Search an area for hidden or undetected creatures or objects. This is crucial for locating hidden or invisible enemies and for locating hidden items, secret doors, and hazards like traps.
If you’re looking for creatures, you can choose to search a 30-foot cone (a conical area measured from our character’s space) or a 15-foot burst (a spherical area 30 feet across) within sight.
If you’re looking for objects, you can search a 10-foot square area adjacent to your character’s space.
You try to tell whether a creature’s behavior is abnormal. This is helpful for detecting if a creature (such as an ally) is acting under the influence of magic.
Perception in Exploration
The Search exploration activity allows you to move slower than your normal travel speed to repeatedly Seek to check for anything hidden, dangerous, or otherwise of interest.