Should work just fine. Take 1-2 levels of Barbarian (depending on whether there's a Rage Power you want) and the rest in Rogue. You might need the Extra Rage feat as with only 1-2 levels of Barbarian you won't have very many rounds per day of raging available to you. Take two-weapon fighting, and get in position to flank and sneak attack.
When to take your first Barbarian level is a difficult question. Taking it at 1st level is very attractive, as this gives you a maximized d12 hit dice which means you'll have 2 extra hit points (which isn't a small amount at low levels). This also gets you full martial weapon proficiency, which is always nice. However, going for Rogue 4 first to get Finesse Training and Debilitating Strike as quickly as possible is also very attractive and the key to making your Rogue devastating in melee. I don't think there's a right answer, but you definitely want to be Barbarian 1 / Rogue 4 by 5th level.
You will want to get at least 3 levels of rogue to get finesse training for daggers. You are also probably want to go with two weapon fighting, so you will want double slice. KitSune Style allows you to make a dirty trick in place of an attack at the end of a charge. You can use Dirty trick to impose the blinded condition to cause your opponent to lose their dexterity bonus allowing you to gain your sneak attack.
Play human for the extra feat and take your 1st 4 levels in unchained rogue. Take two weapon fighting and Combat expertise for your first level feats. At second level take the rogue talent underhanded trick (From Blood of Shadows) to pick up improved dirty trick. At third level take Kitsune style. At this point if you are not flanking or otherwise able to get your sneak attack you can use one attack to blind your opponent and get the sneak attack on the second. At 4th level use the rogue talent combat trick to pick up agile maneuvers. Now start taking levels in Urban Barbarian. At 5th level take double slice to get your full DEX to damage on the second weapon. At 7th level take improved two weapon fighting. At 9th level greater dirty trick makes it a standard action to remove the dirty trick.
The rage power two fanged pounce from the Villain Codex might be good to take.
You may also want to consider unchained barbarian instead of urban. The differences are pretty minor and unchained is more forgiving.
Urban allows him to boost his DEX which gives a bonus to hit, damage (Unchained Rogue), and AC. It also allows him to use INT, DEX and CHA based skills.
Since he will not be boosting CON he will not have to worry about the sudden death from losing the extra HP from that CON.
The accuracy and damage are the same. Unchained actually does a tiny bit more damage with two weapon fighting since that bonus doesn’t take the off hand modifier adjustment. Urban does have better AC, but unchained has better hit points and will saves. Urban having more skill options in combat isn’t nothing, but it probably won’t come up very often, unless you build for that.
Double slice eliminate the damage penalty for the offhand weapon. While the unchained barbarian does not take a penalty for the offhand weapon the DEX to damage still does. So, the unchained barbarian is still doing less damage without double slice. When the character gets a belt of dexterity the extra damage from that will also be affected if they do not have double slice.
The Urban barbarian will have a much higher AC than the unchained barbarian. Not only does he not take the -2 penalty to AC, but he also gains an additional +2 to AC because of the additional DEX. That will also boost his reflex saves and DEX based skills. As the character gains more levels in urban ranger that bonus continues to increase making the difference even greater.
The urban barbarian can use INT, DEX and CHA based skills while raging. Acrobatics disable device, sleight of hand, and stealth are DEX based skills. That means the urban barbarian can actually use controlled rage in non-combat situation and have a better chance of succeeding. The urban barbarian can choose which physical stat he boost, so can also boost climbing and swimming if he needs to. By taking urban barbarian the character is actually building for using rage to boost his skills.
Getting Weapon finesse and DEX to damage quickly is more important than twin fanged pounce. If the character is starting at 1st level it is better to take the first 4 levels in unchained rogue. Not only does it get weapon finesse and finesse training it is using rogue talents to pick up feats early. It is unlikely that this character is going to have a high STR so until it gets weapon finesse it has a very low chance of hitting, and until it gets DEX to damage its damage is also going to be poor.
Once you get past 4th, I would probably take most of the levels in urban barbarian. If retraining is available, you can retrain Kitsune Style to Quick Dirty trick at 7th level. If not, you could rearrange when you pick up the feats.
Does Urban not work with unchained barbarian?
I guess I'll ask how many levels of each class would be in a decent build if I reached level 12?
Either Barbarian 1 / Rogue 11 or Barbarian 2 / Rogue 10 would be ideal.
Barbarian 1 or 2 does not give you enough rounds or rage or other benefits to make it worthwhile. My suggestion would be 4 levels of unchained rogue and the rest in urban barbarian. This gives you weapon finesse, finesse training, 2 dice of sneak attack and two rogue talents. Barbarians get 4 skill ranks per level plus INT. If you go human and take skill for the favored class bonus that is going to put you up to 7 skill points per level minimum. That should be able to get enough skill points
Going more levels in rogue is going to lower your BAB which means you do not qualify for some of the feats until higher level. It also means your chance to hit and to succeed in with the dirty trick maneuver is lower.
I also just noticed the barbarian rage power savage dirty trick. That allows you to once per round use a dirty trick in place of a melee attack and adds an additional condition based on the condition of the dirty trick. In the case of blinded the additional conditions staggered. This rage power does require you to be a 6th level barbarian so will come online late but can be devastating. It also eliminates the need for quick dirty trick.
The feats I recommended should work fine on a Kukuri.
I will do a full trial build and see what I come up with.
Barbarian 1 or 2 does not give you enough rounds or rage or other benefits to make it worthwhile.
You can just take the Extra Rage feat, though I admit that is an expense when you already want to be taking two-weapon fighting feats.
With that said, I can see the case for Barbarian 8 / Rogue 4, as it does get you plenty of rounds of Rage per day and +11 attack bonus for that extra iterative, but you do lose Skill Unlock, a lot of Sneak Attack dice (doubly important for Knife Master), and the Advanced Rogue Talent at 10th. I think it really comes down to which Barbarian Rage powers you want and how much you care about them. If not, you can just use your Rogue Talents to shore up your feat selection and take Extra Rage.
Looking it over I think using the dagger instead of a Kukuri is going to be a better choice. Kukuri is a martial weapon so a rogue is not proficient with it. You could make your first level Urban Barbarian instead of rogue, but that is going to mean you don’t start with weapon finesse and delay getting DEX to damage. Since we are using rogue talents to get feats ahead of schedule it also delays other parts of the build. In my opinion it is not worth it. Also the only difference is going to a point on the critical range, unless you take improved critical that is not going to make that much difference.
After actually stating out the build I think splitting the levels equally is going to be more optimal. To get a little more damage I took animal fury as a barbarian rage power to get an extra attack. Bite works with weapon finesse, so you still get to use DEX to hit, but not for damage. But you do get 4d4 extra damage if the target is blind.
Level 1 Knife Master: Two Weapon Fighting, Combat Expertise, Weapon finesse, sneak attack
Level 2 Knife Master: Underhanded Trick (Improved Dirty Trick)
Level 3 Knife Master: Kitsune Style, Finesse Training, sneak attack
Level 4 Knife Master: Combat Trick (Agile Maneuvers)
Level 5 Urban Barbarian: Double Slice
Level 6 Urban Barbarian : Two Fang Pounce
Level 7 Urban Barbarian: Improved Two Weapon Fighting
Level 8 Urban Barbarian : Animal Fury
Level 9 Urban Barbarians: Greater Dirty Trick
Level 10 Urban Barbarian: Savage Dirty Trick
Level 11 Knife Master: Accomplished Sneak Attack, two extra dice of sneak attack
Level 12 Knife Master: Weapon Training (Weapon focus dagger)
The build takes a few levels to develop. Starting at 6th level the character can make a charge and get two dagger attacks, one of those is a dirty trick (Chose blinded condition). The second attack will get sneak attack damage. At 10th level while the character is raging it can make a dirty trick check to blind the target and get sneak attack damage on the rest of the attacks. You still can use the normal methods of gaining sneak attack (flanking, surprise, etc.), but this gives you some option not available to other. At 11th level you will be adding 4 dice of sneak attack.
@ Mysterious Stranger
So for daggers any weapon abilities that stand out for this build or should I just go Strait +s
Also depending on the campaign I'll choose what material to make them out of. Any non-magical adjustments I can make to them to make them feel unique. Visually I'm picturing over size curved daggers for the flavor kind a Fang theme ,
Like for ah example is there rules/ Item for have the dagger on a small rope so icant drop them / hard to disarm them from me?
rogues should be attack from stealth, flanking, invisibility, so +'s are less valuable that extra damage, so go for a +1 or +2 dagger, then add flaming/shock/frost, etc. anything that ups the number of d6's you roll with each attach. a Kukri is nice for the extra crit range, but not that essential since most of your damage is from sneak/element, etc.
yes, there is a rope you can use
Since you are using multiple daggers there is no reason they all have to be the same material or have the same enchantment. Having weapons be different gives you more defenses you can bypass. What materials you should use is going to depend on what creatures are common in the campaign. Another thing I would keep in mind is that some materials may have out of combat uses.
Adamantine has the ability to ignore hardness of less than 20. Having a dagger that can cut through most objects is a definite advantage. I would probably suggest at least one adamantine dagger. For the second dagger probably cold iron or mithral would be a good choice. Mithral counts as silver but does not take the damage penalty.
If you are going to fighting a lot of evil foes Holy might be a good enchantment. Put it on the cold iron/mithral dagger. For the other some sort of elemental damage is probably a good choice. If you can afford it also look into adding ghost touch to the holy weapon.
Also keep lots of normal daggers for this character for throwing at targets. You will not get DEX to damage when throwing but will often be able to get your sneak attack on a thrown dagger. You are a high DEX character with a decent BAB so don’t limit yourself to melee combat.
A +4 Bonus is the equivalent of Adamantine in regards to damage reduction. So consider the cost of materials vs the cost of upgrade
It really comes down to what the character is going to be fighting. Since he is going to need two weapons buying a single weapon with a high enchantment bonus is probably not a good option. Silver and Cold Iron are the most common DR types. It might be worth getting one of each for use in combat. Dealing with incorporeal creatures may also be a concern.
Even if you don’t purchase an enchanted adamantine dagger picking up a non-magic one would be a good idea. Being able to cut through things is something a rogue will find useful.
Unless you have a huge amount of wealth I would not worry about masterwork for throwing daggers. You will probably lose quite a few of them and at 302 gold per dagger that is going to get expensive.
Since you don’t have quick draw you are going to be limited in when and how many daggers you can throw. This is going to be something that gives you a bit more versatility not something you will be doing often.
Daggers are a part of the close weapons group. +3 damage with close weapons and +2 damage for weapon specialization significantly ups the damage floor. Piranha Strike also helps raise the floor.
Correct me if I am wrong but according to AoN Fighter Weapon Groups only the Punching Dagger is in the Close Weapon Group. Most other Daggers are in in Blades, Light Weapon Group.
I think I'll make having multiple Daggers part is the flavor of the character
I'll use a Cold Iron Dagger and a mithral Dagger as My main weapon
Have a Adamtine Dagger and keep a reasonable amount of Master work Daggers on me for throwing
Instead of having a stash of masterwork (or later even magical) Daggers for throwing, maybe safe money and buy a Blinkback Belt. With that you'll be able to throw any Dagger you possess and get it back immediately after throwing it.