| Stimulus | Perception DC | 
 | Hear a battle | -10 | 
 | Smell rotting garbage | -10 | 
 | Hear details of a conversation | 0 | 
 | See a visible creature | 0 | 
 | Smell smoke | 0 | 
 | Determine whether food is spoiled | 5 | 
 | Hear a creature walking | 10 | 
 | Hear details of a whispered conversation | 15 | 
 | Identify powers of a potion by taste | 15 + potion's CL | 
 | Hear a key being turned in a lock | 20 | 
 | Hear a bow being drawn | 25 | 
 | Sense a burrowing creature underneath you | 25 | 
 | Notice a pickpocket | Opposed by Finesse | 
 | Notice a creature using Stealth | Opposed by Stealth |