What's the best way for most rogues to use a bludgeoning weapon to deal non-lethal sneak attack damage?
Short answer: Like normal sneak attacks, but using a sap.
Long answer is that best depends on your definition of best (i.e. awesome/cool or damage per round?) and the type of rogue you're playing. It has multiple parts: 1. How to sneak attack, 2. Why the sap is great for most 3. Why alternatives? 4. What alternatives?
1. How to sneak attack?
In pathfinder is a (complicated) question, that I'll only answer superficially. The easiest way was already mentioned by @KRyan, which is flanking. Other ways involve skill checks, such as via stealth or bluff (feinting), or slight of hand (hiding the weapon until it's in your face). Basically it comes down to the target being caught off guard, that is As Jason Buhlman said
"creatures are denied their Dexterity bonus to AC "if they cannot react to a blow" (CR pg 179 under AC). It was our intent that if you are unaware of a threat, you cannot
react to a blow."
2. Why the sap for most rogues?
In most cases, just using a sap (or two), as suggested by the title of these combat feats is ideal. As it seems you've already noticed, you cannot normally use a lethal weapon to deal nonlethal damage in a sneak attack. This is because using a lethal weapon in this manner gives a -4 penalty to hit, thus makes you less accurate, and sneak attacks are a form of precision damage.
- The sap deals non-lethal damage by default, thus you don't get that penalty to hit, and therefor you can use it for sneak attacks.
- Unlike all other non-lethal weapons, rogues are already proficient with saps.
- The sap is a light martial weapon. Martial means fair damage.
- Light weapons can be used with Weapon Finesse. Most rogues take that feat, as it lets you add your dexterity modifier to the attack rolls, making it more likely that you hit. Most rogues dump strength because their primary damage source are sneak attacks, and because of rogue's low base attack bonus it is important to boost bonuses to attack rolls in order to hit at all.
- Light weapons are more useful for two weapon fighting, make great offhand weapons. Most rogues like two weapon fighting, because (if you're flanking, get to do a full-round action, and actually hit despite the penalties) you can do more sneak attacks per round for devastating damage. Combined with the feats you're asking about the results can be tremendous.
The sap has very few downsides:
- The sap is not two handed (which matters for some brute rogues).
- The sap is not a distance weapon (which matters for sniper rogues).
- The sap can not be used to deal lethal damage (which rarely matters).
3.Why bother with alternatives?#
- Short answer: if you're like most rogues don't bother. While the feat tax is fairly high (a way of saying you need a lot of feats to accomplish what you want), in this case at least Weapon finesse, Two-weapon fighting, Sap Adept and Sap Master, all of which are combat feats, the results are high Damage-per-round.
- However pathfinder allows for diverse rogues, discussed in this guide, some of which might like the alternatives. Note I'm not saying these rogue types are better, but if you are one of these rogue types, then there are alternatives to saps that could be better for you.
4. What alternatives?
- Strange options (Use your fists/hands or exotic weapons)
- Use Bludgeoner feat with any bludgeoning weapon (feat)
- Use Merciful magic on blunt ammunition (160 gp/projectile) +1d6 bonus nonlethal damage
- Use Merciful magic on blunt weapons (8000 gp/weapon) +1d6 bonus nonlethal damage
First
You have to get rid of the penalty for using lethal weapons non-lethally.
Strange options - most likely non-options
Some weapons beside the sap are non-lethal to start with, but very few deal bludgeoning damage. There are some exotic weapons (with which rogues aren't proficient, thus -4 to hit penalty), namely the Bolas and the Softstones sling ammunition. Little starstones ammunition might work as well, but their damage pre-sneak-attack is fixed at 1 and they glow, which a GM might rule makes it harder to sneak attack in the first place. Your fists also count, but normally deal less damage than a sap, and you count as being "unarmed" so when you attack the enemy gets an Attack of Opportunity! Unless you have the Improved Unarmed strike feat. There are ways to make this feasible, such as dipping in monk or ninja to get the feat "for free", but I don't know a "best", or even good way.
Magical enhancement - expensive, but comes with +1d6 bonus damage and versatility
You can magically alter a weapon to make it merciful for the cost of a +1 bonus. However a weapon with a special ability must also have at least a +1 enhancement bonus. So for a "+1 merciful" weapon you're paying 8000 gold pieces. What you're getting is a weapon that not only deals nonlethal damage, but adds 1d6 points of non-lethal damage on top. And it can be deactivated at will to make it lethal again (though without the extra +1d6 bonus).
Note that you can enhance ammunition for 1/50th of the price. So one merciful bullet or arrow costs 160 gp. However by default Weapon rules these will break/lost/be destroyed at 100% of hits and 50 % of misses.
Note also, adding this will get more expensive the more magic a weapon already is. If you find a "Baseball bat +5" that you can use, it might be worth considering the following feat.
Feat - permanent, but expensive, solution
The Bludgeoner allows you to attack without added penalties for using a lethal bludgeoning weapon to deal nonlethal damage. And thereby allows using a lethal bludgeoning weapon to deal nonlethal damage with a sneak attack.
Second
Now that we found ways of getting rid of the penalties (magic or feat) you have to find a weapon and context that's worth the hassle of not just using a sap. Which as said before is hard.
First: The brute type favors strength over dexterity and uses two handed fighting, which is less feat intensive, as with high strength not only do you not need to get weapon finesse to be able to hit things, but you also get bonuses to damage, so that if you hit with a non-sneak attack you're not completely useless. Also a lot of the time in actual play you don't end up getting full round attack actions, because you have to get into position first. A dip in a warrior type class allows for using better big weapons and heavier armor, and with less Dexterity the limited dex bonus to armor class doesn't hurt as much. If and only if you're running with one of these and are going to take a martial level dip (figher, barbarian, etc.) is there anything better for melee than the sap.
Options include a light hammer (can be used as a throwing weapon with 20 ft range), a flail (or heavy flail, either does more damage (1d8, 1d10 with 19-20 crit range instead of just 20) and can be used for some maneuvers), and an Earth breaker (does 2d6 damage, and triple instead of double damage on critical hit).
Note that the math in ideal situations (rogue actually gets the full-round action attacks, and hits) favors the two weapon fighting rogue, who can basically ignore the base damage because of all that bonus damage. Only if you have to spend your move action to feint or charge (with scout archetype) get into position and have only the standard action left to attack with does this build do more damage, and even then only slightly. It's more a preference thing. Still since it takes less feats to achieve this build can perform sooner. Since Bludgeoner is a terrible feat in the long run, you could consider taking it and retraining (costs 50*character level gold pieces and 5 days worth of training time) once you have enough money for merciful (about lvl 5, unless you want to buy other things first).
Result is 2d6 earth breaker + 1d6 merciful + Xd6 sneak dice + 1.5(two handed)*strength modifier + 2X Sap adept + Xd6 Sap Master.
For example for a 6th level character with 18 strength and 1 lvl in fighter, rest rogue, X is 3. That makes 9d6+12, so 21 to 66 non-lethal damage if you can sneak. And "only" 3d6+6, so 9 to 24 otherwise.
Second: The archery rogue is really hard to pull off, because getting sneak attacks in after the first round is difficult. When you do, you want devastating damage to make it more satisfying to play this type of character. The Sap Adept and Master add bonus damage if you can pull it off. However, archery is already fairly feat intensive on it's own, so again not optimal but non the less feasible, and since best to me is what is most fun to you, knowing this is an option is worthwhile.
Blunt Arrows. Like all arrows (unlike sling bullets), pulling them out is a free action. If you're the bow sniper in the bushes kind of rogue, who wants the target to stay alive, this works.
So do normal sling bullets, especially if you're a Halfling with Warslinger (free action reload) or Swift as Shadows (less stealth penalty for sniping) alternate racial traits. Being small also helps for stealth (and thus sniping).
The Light Mace or Battle Aspergillum are equal (light and rogue has proficiency) to the sap, except that they can also deal lethal damage, which as said before isn't much of a benefit. However if you're going with the feat for the arrows, there's no downside to using a light mace instead of a sap.
FYI
Note the Enforcer feat will let you intimidate to demoralize enemies whenever you deal non-lethal damage and if successful the target is shaken (-2 to all their rolls) for a number of rounds equal to the damage dealt. Which with all those sneak bonuses is basically the rest of the fight.
Potentially worth consideration
There's a trait that lets you deal non-lethal damage with slashing weapons. If you are choosing a weapon other than sap for style rather than power (say you want a quarterstaff, or what not), perhaps the GM will let you make up a trait like that.
Another thought: I was working under the assumption that you already have your rogue planned out and are only changing details. If that's not the case, consider taking the first level rogue for trap finding and extra sneak damage, then take some Bounty Hunter levels. At 2nd level, he can choose to make his sneak attack damage counts as nonlethal damage, even if delivered with a lethal weapon (which allows for using blunt arrows). This also would allow earlier access to the sap master feat, due to sneak damage from different sources. (i.e. 1 rogue / 3 bounty hunter had 3 dice of sneak damage, a 4th level rogue has 2) - and it adds proficiency with bolas.
Conclusion
With what ever method you chose, make enemies unaware of what's about to happen, and then non-lethally devastate your enemies!