Currently? Best rogue build is thief with dual hand crossbows.

Hell, once sharpshooter is implemented that might be the best rogue build in full game as well, even when loading is also implemented.

Depends what you want to do, I suppose. Metrics for character strength include more than damage output.

If you're looking for raw damage output though...

You should be able to get 18dex and 16con, assuming you use the hag hair for con.

Dual wield +1 shortswords, thief subclass, apply poison to your weapons or dip them in fire. Attack 3 times a round.

Always park your rogue next to your battlemaster fighter, and give your fighter Menacing Attack. Your rogue will be able to make an additional opportunity attack if the target gets feared.

At level 5 in a full round this equates to 6d6+3d4+5, and a potential additional 1d6+1d4+5. The total averages for damage with no crits or misses accounted for are 33.5 and possibly up to 44.5.

If you can land a hold person on a target, it guarantees that all melee attacks against that target are crits, and your damage total would be approximately 62.

HOWEVER, I've found that sneak is very easy to abuse in this game, and it's easy to keep your rogue out of initiative order, and just sort of sit back and plug whatever they want with a bow without having to worry about turn orders or anything like that at all, so mechanically that's probably the most powerful option.

The best is to initiate the fight with your other party members and then use your rogue, that isn't in the battle, to launch as many arrows as you want in the enemies. So before the enemy can make one move you have already killed everyone.

Astarion because of his bite.

Halfling dual-wielding hand crossbows John Woo style.

Just go theif at lv3 then get dex to 18 on lv4

Thief with its 2 bonus actions is OP. (This is one thing Larian REALLY needs to go back to TTRPG rules about, make using items an action instead of a bonus, then give the bonus action use of items to the Thief subclass only.)

Closing the game and firing up Solasta.

Ask r/Nissan

If you don't mind abusing a hand crossbow glitch then using the thief subclass and sharp shooter lets you do the 10 extra damage with hand crossbows with your two bonus attack shots from your off hand without taking the -5 attack roll penalty. Multiclass rouge 6/ fighter 6 and take archery fighting style for another +2 to attack rolls, ability to wear breastplate, shields, extra attack, action surge, second wind and with the extra feat at lvl 6 from fighter you still end up with 3 out of 4 feats. You miss out on evasion and reliable talent but the stuff you get from fighter is just too good to pass up.

Alternatively if you want to be a crazy assassin then the assassin subclass and half-orc race go like bread and butter. 3X damage on crits from orc and guarantied crits from assassin go crazy.

Assassin is fun with a dagger and/bow of any kind and high dex. Always get a stealth attack on the first round of combat (if I remember correctly it's a stealth attack if the enemy hasn't taken a turn yet?) Hits like a truck.

Not tried thief or arcane trickster yet but they look fun

Hexblade swashbuckler is great. 5/7, 7/5, 8/4, 9/3 are all great

I just finished a hexblade assassin play through 9/3 split, able to upcast shadow blade to max and able to make use of sneak attacks

Aside from the Hexbuckler, you can technically also make the EB Spammer build with Assassin/Thief, Sorcerer, whatever Warlock, and Fighter optionally. They do fill the niche of a Expertise + CHA build, and even though they are traditionally more played with GOO for spreading Fear, Hexblade is still a possibility if you drop Fighter and wanted Medium Armor and Shield proficiency still.

Hex buckler. Thief are not that good since bonus action attacks won't be able to use hexed weapon.

Buckler can use it though

9 Hexblade Warlock / 3 Swashbucker Rogue I think is the move if you want to use Shadow Blade.

If not wanting to use Shadow Blade because it's overkill: 5 Hexblade / 7 Swashbuckler is pretty good. I like using Phalar aluve or Larethian's Wrath w/ GWM. Big hits that also use sneak attack. Can upgrade to Dancing Breeze in Act 3 :)

Thief is great because it gives you an extra bonus action every turn, pair this with dual wielding you can get a lot of damage/utility just from the rogue alone, my first playthrough I went full rogue/thief and enjoyed it

On my honor playthrough I had astarion do the glookstalker/thief and I started by going 3 in rogue to get to thief, then 5 in ranger for the extra attack, and then 2 in fighter for action surge. If you do assassin instead of thief you can get like 8 attacks in the first turn with a haste potion/spell it’s kinda of crazy

Thief is considered the best rogue subclass for one reason: you get a second bonus action. This is great when dual wielding (melee weapons or hand crossbows), because that enables you to attack with bonus actions. It also supports a playstyle where you use one of your bonus actions to hide after attacking each turn, to set up sneak attack the following turn. 3 levels of Thief is also a great multiclass addition to other classes that can make good use of the bonus action, like Monks and Barbarians. Assassin is also good, especially when not dual-wielding. Arcane Trickster sucks.

Gloomstalker/rogue builds are very strong, and generally better than a pure rogue (which falls off at higher levels, from a damage perspective) while having a similar vibe/playstyle. Highly optimized versions of this build are contenders for the best possible single-target damage in the game. The important thing is 5+ levels of Ranger (for extra attack) and 3+ levels of rogue, the rest is up to you. I like to do 5 ranger / 5 rogue / 2 fighter for archery builds. The fighter dip gets you action surge and allows you to have both the archery and two-weapon fighting styles (one style each from ranger and fighter). The rogue subclass is up to you - thief and assassin are both good. I would go for thief if you plan to use hand crossbows, or assassin to maximize first-turn damage with normal bows. It works well to use thief for the first 2/3 of the game, and switch to assassin for act 3.

How you approach the levels in the early game is up to you. Rogue and Ranger are both good early. Personally I prefer rogue, sneak attack and dual-wielding give you better damage potential in the level 1-4 range, when most classes don't really "come online" until level 5. Ranger is one of those classes, but early access to hunter's mark and dread ambusher is also pretty good. Once you hit level 5 it's good to respec into pure ranger to get extra attack as soon as possible, and then start adding rogue levels after that.

This is some fairly in the weeds multiclass min/maxing stuff. If you find that fun like I do, go for it. But don't feel like you have to - the game is generally not hard enough that optimized builds are required, especially if you aren't on the highest difficulty. Any single-class build is good enough to beat the game.

FYI you can freely (well, cheaply and pickpocket the gold back) respec your characters at any time, so it's perfectly viable to change your level split or the order of your classes at any time. And just generally, you're never locked into your build choices so that takes some of the pressure off when leveling up.

My first run I ran a thief rogue, and the extra bonus action was nice since I was dual wielding. I switched to assassin in the rest of my runs because I wanted advantage to sneak attack to start combat, and then an automatic second sneak attack in the first round.

Just pick something. Rogues in 5e are a little under-served, and BG3 doesn't make it any better. Bards get the same expertise they do, so make just as good choices for "who disarms the traps". And all the really hard locks are going to be picked by your wizard casting a Knock spell anyway.

Most power builds involving rogue take just a few levels, most importantly for the extra bonus action Thiefs get get at level 3 (and then use it for some other class ability like a dual wielding fighter -- this answers your question about why thiefs are best).

A pure rogue isn't useless, but it's not going to stand out.

I would recommend starting as ranger getting 5 levels and dipping 3 levels of rogue. After this, I would get 4 levels on fighter (get the defense fighting style, and probably battle master) for action surge + another feat

You could even respec into fighter for heavy armour prof and go for fighter 6, rogue 3 and ranger 4 for an extra feat (max out dex and sharpshooter)

How far in are you?

Pre hard mode you really can’t

Hard mode it gets slightly better

Post Moon Lord is finally stealth strikes start paying off as you have accessories which start doing crazy things.

You need to prioritize the normal attack skill and the invisible skill before others (shadow slash and Molotov). But join the discord for other opinions and stats build priorities

with invisibility and poison cloud at high level, you can alternate both skills to bé able to kill almost any enemy without taking damage

Level up 1,3,5,8,9 first.

Dagger cut is your main skill, I like to use invisibility, shadow cover both to reduce damage nor 0 dmg, poison cloud stuns enemy and do dmg and the dagger attack (it's always critical when you are invisible) for boss fight switch the last 2 skills for poison daggers and Molotov. Stats to prioritise: armour penetration > critical damage > damage > attack speed.

Dex 16, con 14 is probably the only things you actually need. Everything else is pretty arguable and mostly comes down to preferences on mostly secondary trade offs. I'd say that if you want to do social checks good pick Charisma, otherwise take Wisdom as perception is good and wisdom saves suck to fail.

Dex 17, Rest Like u wanna play. Get as soon as possible dex 20, finished

Dexterity. Everything else is preference.

Have you considered the Church of Skirmishing brought to you by our lord and savior Remus71?

If nothing else this should give you some ideas until you get to act 3 for the Bhaalist stuff.

https://www.reddit.com/r/BG3Builds/comments/1k69s59/drunken_master_build_guide/

Monk (Drunk) 8 / Rogue (Thief) 4

shines a spotlight on skirmishing on the drunk monk chassis

the easiest classes to solo honour are EK 12 or some form of rogue with atleast 5 for uncanny dodge or better 7, even 11 and 1 level for proficiensies is very much great.

Of those 3 option, my favorite is the shadow monk multiclass. There are a few variants and Im not sure that that one is my favorite specifically because I dont I care for the fighter dip as much, but Im sure that preference will vary between players. Getting two weapon fighting is definitely nice.

Ive only tested a couple shadow monk variants with thief and assassin, but I think the thief version works better if you want to utilize the dual daggers.

Do the usual gloomstalker/assassin builds not work for dual daggers? Seems like they would.

I've done it with pure assassin 12. It's scary but still fun until you get Bloodlust Elixir, then it's less scary and way more awesome.