Aid Another

You can help another character achieve success on his or her skill check by making the same kind of skill check in a cooperative effort. If you roll a 10 or higher on your check, the character you are helping gets a +2 bonus to his or her check, as per the rule for favorable conditions. (You can’t take 10 on a skill check to aid another.) In many cases, a character’s help won’t be beneficial, or only a limited number of characters can help at once.

In cases where the skill restricts who can achieve certain results you can’t aid another to grant a bonus to a task that your character couldn’t achieve alone.