Within the Core Rulebook, there are three primary uses for Bluff. One can pass a secret message, lie, or feint. All of these uses are, in some way or another, opposed by Sense Motive.

Passing a secret message is simple enough; a DC 15 check will give the intended recipient the message successfully, and the DC increases by 5 if the message is particularly complex. While hitting these DCs automatically makes the message intelligible to their intended recipient, others present may oppose your Bluff with Sense Motive to ‘overhear’ the secret message. It is therefore advisable to boost your Bluff modifier as high as is feasible even for this skill usage’s set DCs.

Lying is even simpler, though often substantially more difficult. It is a directly opposed roll, Bluff vs. opposing Sense Motive. Hitting 100% efficacy with opposed rolls is virtually impossible. For example, if I have a massive +20 Bluff modifier at level 5, I could still roll a 1 and wind up at 21. Even if my ‘opponent’ has only a +1 modifier in Sense Motive, they could still successfully see through my deception. Luckily, this skill usage is virtually always executed out of combat, where Taking 10 is allowable. I suggest taking this option whenever possible to those liars who have invested considerably in Bluff. My previous example would wind up at a DC 30 Sense Motive to successfully oppose, meaning any creature with less than a +10 Sense Motive would have no chance of success. Eliminating this source of variance will usually help liars deceive more consistently.

It is also important to craft your deception well. You don’t want to include too many extraneous details that could trip your mark to the less than complete veracity of your remarks. Your opponent may well know more about the situation than you, and there’s no way of knowing exactly what might render your prevarication implausible. You want the lie to seem as mundane and likely as possible. As an example, I’ll go through some methods of convincing a palace guard unit that the party is their shift relief. My deceptive exemplar will be called Jasper, whose total Bluff modifier for lying is +18. The guard captain’s Sense Motive modifier is +12.

JASPER: We’re your relief. Get some ale and shut-eye. [Takes 10 on Bluff, with a +5 bonus for the target wanting to believe the lie and get off work early. The guard cannot beat DC 33.]

CAPTAIN: Odd, it’s usually Garek that relieves us, and not for another hour. Why are you lot taking over tonight?

JASPER (terrible response): Garek and his unit were sent to the front-lines. Hope they make it back okay. [The player did insufficient research; this country is not at war. Taking 10 with a -20 penalty he wasn’t counting on gives the captain a 100% chance of seeing through the deception.]

JASPER (pretty bad response): Garek retired. You didn’t hear? He’s having a party with his unit right now. You should go. We’d be there if we weren’t scheduled to be on-site right now. [Garek is a young man, unlikely to retire. It would also be unusual for an entire unit to be given the night off for a party. Taking 10 with a -5 penalty for the lie being unlikely, the captain has a 50% chance of seeing through the deception. The GM could even call the lie ‘far-fetched’, and with the -10 penalty to Bluff the captain will have a 75% chance of seeing through the ruse.]

JASPER (alright response): How the hell should I know? We were told to be here an hour ’til midnight, so we’re here. I didn’t question the order; talk to dispatch if that’s how you want to spend your extra hour off. [This response has virtually no extraneous details to trip Jasper up. That said, there’s no really convincing reasons to allay suspicion either. Taking 10 with no penalty, the guard has only a 25% chance of catching onto Jasper.]

JASPER (great response): (same lines as the green response, but this time with forged written orders from a higher-up in the guard. We’ll assume the guard doesn’t see through the forgery.) [The forgery confers a +5 circumstance bonus to the Bluff (under the ‘convincing proof’ category), meaning the captain cannot help but be convinced.]

Oh, and if you can get your mark drunk or high on something beforehand, you’ll have a +5 on your Bluff as well. Frankly, I think that modifier should be a penalty to Sense Motive instead, but oh well.

The final usage I’ll discuss is feinting in combat. I think it best to just quote the rules directly here:

You can also 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.

This is another opposed Bluff check, but opposing a derived statistic (10 +Wisdom or Sense Motive) rather than a skill check. This means that individual targets (or types of monsters) will have far less success variance than we see for lying (as only 1 d20 is rolled rather than two), but a large degree of variance between subjects. That is to say that while a CR 10 Cryohydra‘s Feint DC is only 19, a Contract Devil‘s (also CR 10) considerable Sense Motive modifier puts the feint DC at 36. I can’t find an average Sense Motive by CR table, so I’ll throw out a guess as to the benchmarks for this. A modifier of 10+2 x LVL is probably quite good, 10+1.5 x LVL is good, 10+LVL is mediocre. These benchmarks admittedly break down somewhat at levels 1-4, where the 10+ part is a bigger portion of the benchmark.

I would like to note that I do not believe feinting in combat to be a worthwhile combat strategy for characters to pursue. On average, flat-footed ACs are only 2-5 lower than base AC, and often enemies will have identical FF and normal ACs. That is really not worth giving up an attack (other other standard) action, especially given that it only counts for one’s next attack. Even rogues have far better options to render their targets vulnerable to sneak attack. Shatter Defenses is very potent, especially when combined with the Intimidation Rogue’s Edge. Circling Mongoose can make an Acrobatics focused rogue better at getting the sneaks off.

Stand-out Character Options for the Feint Action

Class/Archetypes features:

The mesmerist gets +1/2 LVL to their Bluff modifier. They can also ignore the 13 INT and Combat Expertise pre-reqs for feint feats. All but the Dreamstalker, Umbral, and Vexing Daredevil archetypes trade out this class feature. The mesmerist can also take the Misdirection trick to occasionally make targets flat-footed against an ally’s attack as a free action.

The Vexing Daredevil archetype improves upon the base mesmerist in terms of feinting. It gets several feint feats as bonus feats, and several nice ‘feint benefits’ that they can use whenever feinting. Blinding Strike and Surprise Strike seem particularly good.

The Sczarni Swindler rogue can feint non-humanoids without penaltyafter third level. I could see four levels of Unchained Sczarni Swindler this being a good multi-class option for a Vexing Daredevil mesmerist.

The Skulking Slayer archetype of Rogue has a great ability to feint as a swift before a charge. Unfortunately, it comes quite late at level 9. They also get some small numerical bonuses on feint attempts.

Feats:

We’ll start with the basics:

Improved Feint – Allows you to feint as a move action rather than a standard. That means you can actually take the attack against FF AC in the same round. This is a major improvement for those who can keep their target flat-footed once they’ve gotten a successful sneak attack off, but struggle to get that first one in.

Greater Feint – The target is flat-footed against your attacks until the beginning of your next turn, allowing for AoOs, attacks taken as swift actions (such as that from the Hurtful feat), or other extra attacks to benefit. Unfortunately, if we have used our move action to do a feint, it will not help a full-attack action.

Blistering Feint – When you successfully feint with a fiery weapon, you get to deal the fire damage automatically. You get a +2 on your feints as well, the gravy on top. This feat is really only good for one build; an Ifrit (its a pre-req) pyrokineticist using the kinetic blade wild talent. One of those with Improved Feint could take a move action to deal weapon damage with their Bluff, and then go against flat-footed with their standard attack. I think this will work better with the Kinetic Knight archetype, but I haven’t gotten a real chance to look at that yet.

Deceptive Exchange – When you successfully feint an enemy with the ability to grasp things, you can get them to take something from you instead of making them flat-footed. I rated this green because I think its cool enough that people should read about it, but it is very difficult to imagine a great way to build around this. If you could use it to pass cursed items without getting cursed yourself somehow, maybe. Delayed bombs are another good route to go, but for most I think it would be easier just to throw the damn things.

Feint Partner (Teamwork) – If someone with this feat feints, anyone else with the feat also gets their next attack against flat-footed. This makes the action do more, but unfortunately doesn’t allow other benefits of feint like Blistering or Deceptive Exchange.

Improved Feint Partner (Teamwork) – If your partner feints, you get an AoO. Since you have feint partner, obviously this AoO will be against FF AC as well. This could be nice in a teamwork pair with Outflank or Seize the Moment and high critical range weapons. Any opportunity to begin an AoO cascade can be incredible.

Feinting Flurry – You can sub your first attack on a flurry of blows for a feint attempt. I could see a UMonk/URogue getting some mileage out of this. Particularly with Greater Feint, it is an improvement over taking a move action to drop our opponent’s AC. One could potentially ki-flurry to feint and make two full-BAB attacks and iteratives against FF AC in the same round. Still, you lose an attack to do it, and it is only for a small subset of characters.

Improved Feinting Flurry – Basically lets you skip taking Improved Feint and Greater Feint, as your successful feint will last until end-of-turn with this. Not as good as AoOs, but it lowers the feat cost of feint-building by 1 for anyone with flurry.

Illusive Gnome Style/Trick/Bewilderment – Just don’t bother with these. I honestly cannot imagine it every being worth your precious feat slots.

Two-Weapon Feint / Improved Two-Weapon Feint – Work exactly like Feinting Flurry and Improved Feinting Flurry, but for those who use TWF instead of flurry. This is worse for two reasons: TWF is already a very feat-intensive combat strategy (TWF, ITWF, GTWF, Double Slice) and trying to fit feinting tricks into your build as well is less attractive than it is to the monk. After all, flurry doesn’t take a single feat. The second reason is that TWF doesn’t have the option to spend a ki point and get another full-BAB attack against FF AC.

Mesmerizing Feint / Greater Mesmerizing Feint – This is only for mesmerists, and if you’re building for feinting as a mesmerist you’re probably a Vexing Daredevil getting this puppies for free. They essentially allow you to bypass immunity to feinting, and instead you just take some penalties on the rolls.

Moonlight Stalker Feint – Might be the best method of feinting I’ve seen, as it lowers the action economy cost to a swift action. This costs no one any attacks, really. Unfortunately, most characters won’t be able to leverage this feat terribly well. You need racial LL/Darkvision, Combat Expertise + INT 13, Blind-Fight, Moonlight Stalker, and the ability to consistently give yourself concealment. Still, I can imagine building towards this working out well. For example, an Elf/Wayang/Half-Orc URogue/Warpriest could combine this with Greater Feint and essentially always get Sneak Attack, with the +2 to attack and damage from Moonlight Master. Still, the pre-reqs are a bit brutal, and I think to leverage it properly you’d need some hefty multi-class nonsense.

Slayer’s Feint – Use Acrobatics instead of Bluff to feint. This can be awesome for Dex based characters, especially if they already intend to buy wondrous items improving their Acrobatics modifiers. Unfortunately, it requires either dipping a level of Slayer or taking the sub-par Acrobatic feat. Still, it could be worthwhile for some.

Suerte de Capote – This is an equipment trick. You get some numerical bonuses to feint attempts when wielding a dueling cape, and you can auto-entangle anything you successfully feint. That entangle ability is really quite nice.

Standout Items

Cape of Bravado (slotless | 7,000 gp) – This item grants a +5 competence bonus on feint attempts so long as it is draped over one arm. Useful for those who leave a hand free (like Swashbucklers), and as a cherry on top it grants a +1 insight bonus to all three AC types.

Mask of Stony Demeanor (head slot| 8,000 gp) – This item used to be a no-brainer at 500 gp, but was re-priced to maintain game balance. It grants a +5 on feint attempts, and a whopping +10 bonus on Bluff checks made to lie. It imparts a -5 penalty on passing secret messages, but rarely is that an issue.

Deceptive Weapon Property (+1 enhancement) – I don’t think it’s particularly worthwhile. The bonus stacks with everything else, but it typically winds up being really expensive for what it’s doing. To get a +4 bonus to feint attempts, you’re effectively putting that last +1 (to a total effective enhancement of +5) at a cost of 18,000 gp. That’s a big chunk of change for a skill bonus. It does have the added benefit of allowing an immediate action feint whenever you crit, so I guess rapier wielders and similar might like it.

Bracelet of Bargaining (14,500 gp) – It’s pricey, but for a low-priority slot you get a nice +5 on not only Bluff, but Diplomacy and Sense Motive as well. It’s not a bad deal if you’re a party face.

Eyes of the Liar (16,000 gp) – Outside of campaigns where telepaths are a frequent concern, these just aren’t worth the gold. They’re basically the same as the Bracelet of Bargaining, but replace the bonus to Diplomacy and Sense Motive with immunity to telepathy.

Mummer’s Ruff (3,500 gp) – Grants +10 competence bonus on Bluff checks made to imitate another’s voice. I always thought that was part of a Disguise check, but whatever. You also get 5/min daily of ventriloquism, which is neat. For ‘master of disguise’ characters, I can see this being a worthwhile purchase, especially given its low cost.

Mulberry Pentacle Ioun Stone (10,000 gp) – Gives the same bonuses as the Bracelet of Bargaining, except the Sense Motive is only a +2 (and you have to resonate it for that). Still, it saves you a wrist slot and almost 5k, so good deal.