Using Perception

Perception Tests are for any situation involving basic senses (sight, hearing, smell, touch, or taste) where you’re looking for something that isn’t obvious. Your gamemaster might call for you to make one, or you can call for a Perception Test by taking an Observe in Detail Simple Action to get a handle on what’s going down around you. Making the threshold on a Perception + Intuition [Mental] Test indicates that you’ve noticed something subtle or important (or both)—net hits determine how much detail you get. If someone is deliberately trying to hide from you, they’ll oppose your test with their own skill (Using Stealth Skills, p. 136, CRB).
Perception Tests involving vision (which is most of them) use the same Visibility and Light modifiers as attacks do in combat (Environmental Modifiers, p. 173, CRB). Other modifiers are listed on the Perception Test Modifiers table. If a bunch of people are making a Perception Test and looking for the same thing, use a Teamwork Test (p. 49, CRB).  

PERCEPTION TEST MODIFIERS

SITUATION DICE POOL MODIFIER
Perceiver is distracted –2
Perceiver is specifically looking/ listening for it +3
Object/sound not in immediate vicinity -2
Object/sound far away -3
Object/sound stands out in some way +2
Interfering sight/odor/sound -2
Perceiver has active enhancements + (Rating)
Visibility and Light Environmental Factors, p. 173, CRB
 

PERCEPTION THRESHOLD

ITEM/EVENT IS THRESHOLD EXAMPLES
Obvious/Large/Loud 1 Neon sign, running crowd, yelling, gunfire
Normal 2 Street sign, pedestrian, conversation, silenced gunfire
Obscured/Small/Muffled 3 Item dropped under table, contact lens, whispering
Hidden/Micro/Silent 4 Secret door, needle in haystack, subvocal speech