If I'm reading the packet correctly, it looks like a sneak attack could be made on the second attack while two-weapon fighting and retaining advantage on the first attack. Is this correct? If so it seems the optimal way to play the rogue would be two-weapon fighting, make the first attack with advantage, maximizing the chance of hitting, getting crits, deadly strike damage, and ability modifier damage, and making the sneak attack on the second attack, which would not affect the chance of getting sneak attack damage (since sneak attack attempts can only be made once per turn.)

Two-Weapon Fighting: When you wield two light melee weapons at the same time, you can use your action to make an attack with each weapon. You don’t add your ability modifier to the damage of the second attack.

Sneak Attack: Once per turn, if you do not have disadvantage when making an attack, you can attempt a Sneak Attack. When you do so, you make the attack with disadvantage. If the attack hits, it deals 1d6 extra damage.

Backstab: Once on your turn when you make a melee attack, you can give yourself advantage on that attack roll if there is at least one creature hostile to your target within 5 feet of it.

You would only gain advantage with one of the attacks, so either gain advantage on the primary attack and still retain disadvantage on the secondary attack, or make both attacks normally.

Also note the 'Once per turn' and 'Once on your turn'. Would this mean that Sneak Attack could be applied to Reaction Attacks of Opportunity?

Disclaimer: Wizards of the Coast is not responsible for the consequences of any failed saving throw, including but not limited to petrification, poison, death magic, dragon breath, spells, orvorpal sword-related decapitations.That is the same conclusion I developed from reading it, now the question becomes which does more

Advantage + Disdvantage or Double Normal

Even if you have 5 causes for advantage and 1 cause for disadvantage they completely cancel each other out and you make a normal roll. Likewise for the reverse. So you can't just double stack advantage to keep you there despite disadvantage. I didn't look closely enough at the last packet to know if this is new or not.

But it could let you make a normal attack with advantage and the sneak attack normal, yeah. Someone else was doing math on advantage vs normal vs disadvantage and the average damage through hit chance, I'm pretty sure until later levels attacking at advantage is always better than normal sneak attacks, and attacking normal is better than disadvantaged sneak attacks.

That was the point, I know that multiple advantage and disadvantage cancels out, and cannot stack. However, given the nature of backstab, you choose to apply it to one attack once on your turn, its therefore feasable if you had multiple abilities with a similar effect, i.e two abilites that allowed you to gain advantage for one attack, that you could apply advantage to each attack from two-weapon fighting (separately and once from each effect), and then make a sneak attack with the second attack, which would not be at disadvantage.

Given the wording, I believe so. Seems particularly useful with seize the opportunity and riposte.

(Rogue using rapier mainhand, short sword offhand)

EDIT: I did not factor in criticals. That might shift things in the other direction. Math is giving me a headache. Normal crits occur 5% of the time, mainhand advantage crits occur 9.75% of the time, and offhand disadvantage crits occur 0.25% of the time. Mainhand crits (24.5 avg dmg) aren't as great as offhand crits (39.5 avg dmg). I feel like it might balance out over the long run.

AC 10Level 9 rogue (+6 to hit, deadly strike, +4 dexterity, +5d6 sneak attack) vs. AC 10:

Mainhand normal: 2d8 + 4 (13 avg), 85% chance to hit => Average DPR 11.05

Offhand normal: 1d6 + 5d6 (21 avg), 85% chance to hit => Average DPR 17.85

Total DPR:

28.9Level 9 rogue (+6 to hit, deadly strike, +5d6 sneak attack) vs. AC 10:

Mainhand w/adv: 2d8 + 4 (13 avg), 97.75% chance to hit => Average DPR 12.71

Offhand w/dis: 1d6 + 5d6 (21 avg), 72.25% chance to hit => Average DPR 15.17

Total DPR:

27.88Normal wins by 1.02 DPR

AC 14

Level 9 rogue (+6 to hit, deadly strike, +4 dexterity, +5d6 sneak attack) vs. AC 14:

Mainhand normal: 2d8 + 4 (13 avg), 65% hit chance => Average DPR 8.45

Offhand normal: 1d6 + 5d6 (21 avg), 65% hit chance => Average DPR 13.65

Total DPR:

22.1Level 9 rogue (+6 to hit, deadly strike, +5d6 sneak attack) vs. AC 14:

Mainhand w/adv: 2d8 + 4 (13 avg), 87.75% hit chance => Average DPR 11.41

Offhand w/dis: 1d6 + 5d6 (21 avg), 42.25% hit chance => Average DPR 8.87

Total DPR:

20.28Normal wins by 1.82 DPRAC 18Level 9 rogue (+6 to hit, deadly strike, +4 dexterity, +5d6 sneak attack) vs. AC 18:

Mainhand normal: 2d8 + 4 (13 avg), 45% hit chance => Average DPR 5.85

Offhand normal: 1d6 + 5d6 (21 avg), 45% hit chance => Average DPR 9.45

Total DPR:

15.30Level 9 rogue (+6 to hit, deadly strike, +5d6 sneak attack) vs. AC 18:

Mainhand w/adv: 2d8 + 4 (13 avg), 69.75% hit chance => Average DPR 9.07

Offhand w/dis: 1d6 + 5d6 (21 avg), 20.25% hit chance => Average DPR 4.25

Total DPR:

13.32Normal wins by 1.98 DPRI double checked your numbers and they are correct. Criticals do not make a significant difference. Two weapon fighting is another reason why you don't want disadvantage on your offhand attacks, if you take that feat (and you should).

AC 14Level 9 rogue (+6 to hit, deadly strike, +4 dexterity, +5d6 sneak attack) vs. AC 14:

Mainhand normal: 2d8 + 4 (13 avg), 60% hit chance => Average DPR 7.8

Crit MH N: 1d8+20 (24.5) 5% >> 1.23

Offhand normal: 1d6 + 5d6 (21 avg), 60% hit chance => Average DPR 12.6

Crit OH N 1d6+36 (39.5) 5% >> 1.975

Total DPR:

23.61

Level 9 rogue (+6 to hit, deadly strike, +5d6 sneak attack) vs. AC 14:Mainhand w/adv: 2d8 + 4 (13 avg), 84% hit chance => Average DPR 10.92

Crit MH N: 1d8+20 (24.5) 9.75% >> 2.39

Offhand w/dis: 1d6 + 5d6 (21 avg), 36% hit chance => Average DPR 7.56

Crit OH N 1d6+36 (39.5) 0.25% >> 0.1

Total DPR:

20.97

I think Crits matter, problem is your big damage is never going to really crit with disadvantage2.64 DPR (12.5% more)

Edit - No Sneak Attack

Level 9 rogue (+6 to hit, deadly strike, +5d6 sneak attack) vs. AC 14:

Mainhand w/adv: 2d8 + 4 (13 avg), 84% hit chance => Average DPR 10.92

Crit MH N: 1d8+20 (24.5) 9.75% >> 2.39

Offhand: 1d

8(4.5 avg), 60% hit chance => Average DPR 2.7Crit OH N 1d6+6 (9.5) 5% >> 0.475

Total DPR:

16.485