You can use Bluff to deceive others, to pass secret messages, and to create diversions and feints in combat. The Bluff skill is an extremely versatile, though sometimes misunderstood, social skill. Unlike Diplomacy and Intimidate, which can directly push their target toward a course of action, Bluff feeds the target misinformation. A skilled user of the Bluff skill needs to understand how the target’s mind works, in order to deliver just the right misinformation to achieve the desired results. The disadvantage is that such manipulation is less predictable and more difficult to pull off, but the advantage is that the target is not aware that he is being manipulated, whereas even the most successful Diplomacy or Intimidate attempt leaves the target realizing who has convinced him to take action.
Pass Secret Message: You can use Bluff to pass hidden messages along to another character without others understanding your true meaning by using innuendo to cloak your actual message. The DC of this check is 15 for simple messages and 20 for complex messages. If you are successful, the target automatically understands you, assuming you are communicating in a language that it understands. If your check fails by 5 or more, you deliver the wrong message. Other creatures that receive the message can decipher it by succeeding at an opposed Sense Motive check against your Bluff result. Using Bluff to deliver a secret message takes twice as long as the message would otherwise take to relay.
Don't underestimate the benefit of using Bluff to send messages through innuendo. Since the DC to send a message is static (15 or 20 depending on the message's complexity), you can quickly reach the point that the message itself is reliable, and thus the only risk is being intercepted, which would have happened anyway if you didn't make the attempt.
Feint: You can use Bluff to feint in combat, causing your opponent to be denied his Dexterity bonus to his AC against your next attack. The DC of this check is equal to 10 + your opponent's base attack bonus + your opponent's Wisdom modifier. If your opponent is trained in Sense Motive, the DC is instead equal to 10 + your opponent's Sense Motive bonus, if higher. Feinting in combat is a standard action.
EDITORS NOTE: There is additional information in Ultimate Intrigue and Giant Hunters Handbook