first time building a rogue

[Mnemius]

We just had some players leave, and rather than bring new people in mid story, we're starting a new one!
Party so far has
dwarf cleric
half-elf sorcerer (focus on blasting)
warpriest (whips)
Bard (face)
Halfling Ranger

and then me, as an unchained rogue (seemed like trapfinding might be useful)
Thinking as a slyph. I haven't played a rogue before, everything has been something with spell slots... be it paladin, warpriest, witch, bard, etc. Building to arcane trickster seemed like an idea... but MAD and my DCs would probably suck.

I don't know starting level yet, probably somewhere between 1 and 5.
Thinking to start with the following stats (25 point buy)
Str: 9
Dex: 20 (18 + 2 for slyph racial)
Con: 12 (14 - 2 slyph)
Int: 14 (12 + 2 slyph)
Wis: 12
Cha: 10

thinking of starting with a rapier and studded leather.
Is two weapon fighting worth going towards?

Thinking feat at level 1 will be improved initiative. (Unchained rogues get weapon finesse for free at level 1... and dex to damage at 3)
For traits, Reactionary... and... uh... ideas?

Canny Observer and Trap Spotter for my first two rogue talents.

Level ups feel quick with this DM, to the point that it seems like wealth falls behind till he starts throwing enemies all armed with magic weapons at us. Good luck getting specific items you want.
Trying to shop is always an adventure because he likes to turn all shopping trips into RP, and half the time it's like "It'll take a week but I can get it for ya." We can't get back to that town for a month...
Starting, a character has whatever they had the funds to be created with.

On the bright side, only time a crit confirm roll is called for is if the monster would take you a natural 20 to even hit it. That applies to everything though... so yeah, splatted characters are a thing. I know the GM likes to use an alternate spell system where all the spells cost points equal to their level, points can be regenerated at 1 per full round action that leaves you wide open to attack (so out of combat cheese), and classes get points based upon their spell casting progression. (I've broken that system several times already with him. Trying not to again.)

Any tips and tricks for a rogue? Things that sound good but actually suck? Hidden gems people miss?

[BowStreetRunner]

Is two weapon fighting worth going towards?The biggest problem with two weapon fighting is that it normally spreads out its total damage among multiple hits, whereas power attacking with a two handed weapon puts all that damage into a single hit. This can appear to be evenly balanced, but when damage reduction comes into play suddenly the DR gets multiplied by the number of hits and two weapon fighting falls behind. So for two weapon fighting to be effective, you need a way to get increase the damage of every hit. Then that damage also gets multiplied over every hit and overcomes the DR. Fortunately, Sneak Attack has the potential to accomplish this - if you can mange to apply sneak attack damage to all of those hits. (Scenarios where it only applies to the first hit or you are only making a single attack aren't going to help here.)

Rogue builds love two weapon fighting. However, you need to consciously seek out ways to full attack with sneak attack damage. Flanking is probably the easiest way to achieve this, followed by attacking while an opponent is flat-footed. Other methods like using invisibility often only give you sneak attack on the first hit.

Just remember, you are going to be much more squishy than the fighter types. So work out a strategy that allows you to get next to opponents you can drop with your overwhelming damage and avoid being next to someone who is going to take it and then full attack you back on their turn.

[Ellrin]

If you’re interested in “rogue with casting,” well, arcane trickster is certainly one path, but you might also consider the eldritch scoundrel rogue archetype, which gives the rogue native 2/3 casting, or the investigator, which in many ways is just better at rogue things than actual rogues (including trapfinding), while also getting 2/3 pseudo-casting.

Also regarding crit confirmation: that’s there to protect players, not hinder them. I mean, if your group doesn’t mind that house rule, that’s fine, but taking that out really hurts the PCs way more than their enemies.

[Mnemius]

Well, now I know a little more of our campaign setting. Not Golarion. We're in an empire that follows the Golarion pantheon, but there are other pantheons too.

The gods (in general) test this world every thousand years, We are at that thousand year junction. Failing the test means destruction of the mortal realm? plane? planet? This has supposedly repeatedly happened, no stories of a world surviving.

My chaotic good unchained rogue will become very, very angry at learning of this callous disregard for life, for not being allowed to make their own choices, for snuffing out the innocent.

The goal now... steal divinity itself, those jerks who call themselves gods don't deserve it if they are just going to snuff the entire planet for failing some test. And/or stealing the keys to the afterlife because there's probably several worlds worth of angry souls due to the gods' cruelty.

Starting at level 4, unchained rogue, chaotic good. Pathfinder material is legal. Ideas/optimization?

[Palanan]

Originally Posted by Ellrin
…but you might also consider the eldritch scoundrel rogue archetype….

Seconding this. If you’re starting at fourth level, then you’ll be casting second-level arcane spells, and you’ll be free to focus on utility spells while the half-elf sorcerer is blasting things.

Also, as a sylph you’ll have access to the Air Insight alternate racial trait, which lets some of your summoned monsters last for two extra rounds. You might also consider the Whispering Wind alternate racial trait, which gives you a +4 to Stealth.

[Kurald Galain]

Is two weapon fighting worth going towards?
For a rogue? Yes, definitely.

I've found Arc Trickster to be problematic though, because sneak attack damage applies to only one hit of (e.g.) scorching ray. Eldritch Scoundrel is solid, though. Take the Accomplished Sneak Attacker feat to get your SA damage back. Alternatively, Ninja is decent for a magical rogue, for its swift-action Invisibility ability.

You're probably over-investing in initiative; pick a trait that boosts damage (e.g. Blade of the Society) or that helps your AC or saves.

[Geddy2112]

Seconding this. If you’re starting at fourth level, then you’ll be casting second-level arcane spells, and you’ll be free to focus on utility spells while the half-elf sorcerer is blasting things.

Also, as a sylph you’ll have access to the Air Insight alternate racial trait, which lets some of your summoned monsters last for two extra rounds. You might also consider the Whispering Wind alternate racial trait, which gives you a +4 to Stealth.

+1 to eldritch scoundrel and +1 to whispering wind. With good dex and wanting to be sneaky as a rogue anyways, might as well get a racial +4. I also suggest breeze kissed to replace air affinity for +2 AC against ranged and the ability to bull rush or trip enemies once a day.

Even with garbage DC's, as said above just focus on buffing and utility spells. Leave blasting to the sorcerer. With a good enough mix and spell points, you should be able to fill the arcane niches the bard and sorcerer missed.

If you are not going eldritch scoundrel I would consider making strength 8, wisdom 14 and int 12 to get a bit better will save and perception bonus. With 12 int and 8 skill ranks you are already good at everything, and with the campaign being as is UMD rogue is not really going to work. Max perception, acrobatics, maybe a social skill(your bard cleric and sorcerer should cover this fine but never bad) stealth, disable device, then the world is your oyster skillswise.

For two weapon fighting, you generally want paired weapons to benefit from skill focus, improved crit, dex to damage, etc. Short swords are the gold standard, but you can get kukri's with knife master archetype for crit goodness, which is great with your crit rules. Also consider dual wielding sap's as backups to have the ability to knock stuff out. Saps pair well with the enforcer feat if you wanna focus on debuffing(great with your 4th level debilitating injury) and want to focus on intimidate. If you are going to TWF you need to get it as your first level feat; I agree your initiative will be fine enough as is without improved initiative but it is never a bad feat. TWF is feat intensive, meaning you need rogue talents to carry you.

One rogue talent worth considering is dampen presence-at higher levels negating blindsight/sense is a big deal for stealth characters, and this allows you to bypass the skill focus requirement. Get on good terms with your ranger bro and have them spot you negate aroma and pass without trace, making you dang near impossible to find. The bard might even be nice and invis you if you don't bring your own to the party. With spell points being a thing, there should be no reason these are not constant or near constant on you.

If you are starting level 4 get something better than studded leather; eventually you will use only dex for AC so anything with 8+ max dex bonus is worth looking at. Even a humble haramaki is fine so you can spend more money on your weapons and belt of dex. Carry a crossbow or shortbow for backup ranged options just in case.

[Vyanie]

What is available to you? Are you looking for a damage machine, a stealth type person? a skill monkey?

Personally I love going goblin and getting color thief trait with the second one depending on the campaign,
My stats usually are something similar to 10/18/14/12/10/7 before racials, if need be i can drop dex to 17 and put points into wisdom
Knife master archtype if you dont mind dropping trapfinding for extra damage,
Feats
1 Two Weapon fighting
3 extra rogue talent
5 Flensing strike

for rogue talents
Bleeding attack
Faste stealth
False attacker (or dampen presence)

You can obviously change out the lvl 3 feat for anything else you want but with this you become both amazing at damage and really help with debuffing an enemy sicken + rogue debuff + destroying natural armor = amazing
with this also if the enemy doesnt have a special way to find you you should never fail stealth checks.

[RNightstalker]

If you want to do TWF, get a Rogue Blade or two. It lets you blink for 6 rounds 2x/day...when you're blinking you're attacking from concealment so you get to SA and you have a miss chance so you don't get smashed when it's not your turn...almost got TPK'd by one around 10th level or so.