Check: Make a Listen check against a DC that reflects how quiet the noise is that a character might hear or against an opposed Move Silently check. The GM may call for a Listen check by a character who is in a position to hear something. A character can also make a Listen check voluntarily if he or she wants to try to hear something in the character's vicinity. The GM may make the Listen check in secret so that the character doesn't know whether not hearing anything means that nothing is there or that the character failed the check. A successful Listen check when there isn't anything to hear results in the character hearing nothing.

-10A battle
0People talking
5A person in medium armor walking at a slow pace, trying not to make noise
10An unarmored person walking at a slow pace, trying not to make any noise
15A 1st-level Fast hero sneaking up on someone 1
20A tiger stalking prey 1
30A bird flying through the air
+5Through a door
+15Through a solid wall

1 This is actually an opposed check; the DC given is a typical Move Silently check result for such a character or creature.

ConditionCheck Penalty
Per 10 feet of distance-1
Listener distracted-5

Try Again: A character can make a Listen check every time he or she has the opportunity to hear something in a reactive manner. As a move action, the character may attempt to hear something that he or she failed (or believes he or she failed) to hear previously.

Special: When several characters are listening to the same thing, the GM can make a single 1d20 roll and use it for all the listeners' skill checks. A character can take 10 or take 20 when making a Listen check. Taking 20 means the character spends 1 minute attempting to hear something that may or may not be there to hear.

A character with the Alertness feat gets a +2 bonus on all Listen checks.

A sleeping character can make Listen checks, but takes a -10 penalty on the checks.

Time: A Listen check is either a reaction (if called for by the GM) or a move action (if a character actively takes the time to try to hear something).