Unchained rogue damage output

Question

I'm in the middle of my first campaign and am still confused about calculating hits and damage.
I'm a level 5 unchained rogue, 18 Dex, weapon focus on daggers and 2 masterwork mithral daggers. I just got TFW, so what am I looking at in terms of combat capabilities, numbers wise?
I don't understand when should I use my BAB: when rolling the attack, the damage or both?
It feels like I can do a lot of damage with my 3d6 sneak attack, but I am missing something.
Please explain to me how to do these calcs!

Answer 1

Base attack bonus is—as the name hints at, although somewhat subtly—a bonus on your attack rolls. It is not added to your damage rolls, or really to much of anything else (your combat maneuver bonus includes it, that’s the only thing I can think of off the top of my head, and that’s kinda-sorta a special attack bonus).

So as a 5th-level rogue (unchained) with 18 Dex and a masterwork weapon, your full attack bonus is +8 (+3 from BAB, +4 from Dex, +1 from masterwork). If you use both of those daggers at the the same time with the Two-Weapon Fighting feat, you take a −2 penalty on each attack, so you make two attacks at +6. Remember that you can only use two-weapon fighting as part of a full attack: you can’t move more than 5 feet (via the 5-foot step free action) on the same round as you do that. In any round where you use an actual move action, you’re limited to a standard attack, which is just the one attack at +8.

Your dagger damage, for your main hand attack (or your one attack, when using the standard attack option) is 1d4+4 (1d4 for a Medium dagger, +4 from Dex thanks to the unchained rogue’s finesse training). Your offhand attack (the second one during a full attack) does 1d4+2 damage (the Dex bonus is halved for an offhand attack).

In both cases, if the target is flanked or denied its Dexterity bonus to AC (and it’s not immune), you also add +3d6 damage from sneak attack. Important: sneak attack applies to every qualifying attack. There is no limit on how many attacks can benefit from it. If you qualify for sneak attack because of something that’s ruined by attacking—like hiding, or an invisibility spell—then your subsequent attacks won’t get sneak attack, but if you qualify for sneak attack because of something persistent—like flanking—you can get sneak attack on every attack.

So you should be aiming to be making two +6 attacks per round, for 1d4+4+3d6 damage and then 1d4+2+3d6 damage. This is usually most easily achieved through flanking.