D&D 5E Rogues are Awesome. Is it the Tasha's Effect?

[Ovinomancer]

Your made a small error here. I think at AC16 your numbers for a Rapier would have been correct.

With +3Dex and +2 proficiency vs 15AC you have a 50% non-crit hit chance (10-19 rolled) and a 5% crit chance (20) and a 45% miss (1-9 rolled).

Numbers underlined and bolded below are the difference:

Case1:
CASE 1 (non crit hit) 0.7
--case 1a -- first non-crit hits, second misses -- .5*.45 = 0.225
--case 1b -- first misses, second non-crit hits -- .45*.5 = 0.225
--case 1c -- both non-crit hit -- .5*.5 = 0.25

.225+.225+.25=0.7

Average damage Case 1: 14.5 * 0.7 = 10.15

Case 1 + Case 2 average damage: 10.15 + 2.535 = 12.685

For TWF

Case 1 -- 1st non crit hits, second misses - 13.5*.5*.45=3.0375
Case 2 -- 1st misses, second non-crit hits - 10.5*.45*.5=2.3625
Case 3 -- 1st crits, second misses - 24*.05*.45=0.54
Case 4 -- 1st misses, second crits - 21*.45*.05=0.4725
Case 5 -- both non-crit hit - 17 * .5*.5=4.25
Case 6 -- 1st crits, second non-crit hits 27.5*.05*.5=0.6875
Case 7 -- 1st non-crit hits, second crits 20.5* .5* .05=0.5125 <--- This is where the TWF really loses damage
Case 8 -- both crit 31*.05*.05=0.0775

Total=11.9400

Yup, I was using .5 for the total hit chance instead of .55. Same numbers for your level 3, but we still diverge for 7 and 11.

I get ADV 20.7675 and TWF 20.73 for level 7, and ADV 29.4 and TWF 30.35 for level 11.

At level 7, overall hit chance is .65, DEX is 4, and Sneak is 14. At level 11, overall hit chance is .75, DEX is 5, and sneak is 21. These are the only changes happening. The effect on crit chances for TWF is still present -- it shifts dramatically towards both hit 1 crit. This is the same spreadsheet that generates you level 3 numbers and does so when I corrected the base hit chance from .5 to .55. So, approach was correct, data entry failed.

 

[AtomicPope]

I ran a campaign to 20th level and beyond (lots of Boons), and the Arcane Trickster does VERY well. Even though they have a relatively small spell list, it goes far due to the high number of skills, feats, and abilities available to the Rogue class. Their Magical Ambush is extremely powerful. Spells like Shield and Mirror Image are extremely powerful for a Dex class with light armor. High damage is not really a big concern. From my experience they do just fine for damage. Yes, it's not as high as a DPS Paladin or Fighter build but they have a deep tool box and much higher survivability than other Rogue sub classes with spells like Misty Step to simply escape an impossible situation. From my experience as a DM to a 3 year campaign, the Arcane Trickster is very difficult to pin down and hurt.

 

[FrogReaver]

I like combats with lots of weak foes supporting the stronger foes (which 5e shines in), so this is more a case in point than a trivial example for me.

Trivial doesn’t mean uncommon, it means obvious. It’s obvious that if you are attacking a bunch of enemies both characters can kill in one hit that the character with more attacks and less damage per attack will perform better.

That may be a rarity or very common depending on campaign.

 

[Mistwell]

Steady Aim/Familiar Help Action + Booming Blade/Green Flame Blade + Magic Rapier + Sneak Attack continues to be incredibly devastating to opponents. Particularly when I have Mirror Image up prior to doing it.

The danger of course is I remain next to a foe in melee combat. But realistically, very few foes survive a single attack from that so far in my experience with this PC. This little halfling is dishing out so much damage in a single hit that he's one-shotting frequently. And even if he does get caught, his AC remains decent, if he has Mirror Image up the attack usually hits one of those instead, and he can use his reaction to halve the damage of any attack with Uncanny Dodge. Evasion seems to come up fairly often as well.

Rogues really are pretty awesome.

 

[Ovinomancer]

Steady Aim/Familiar Help Action + Booming Blade/Green Flame Blade + Magic Rapier + Sneak Attack continues to be incredibly devastating to opponents. Particularly when I have Mirror Image up prior to doing it.

The danger of course is I remain next to a foe in melee combat. But realistically, very few foes survive a single attack from that so far in my experience with this PC. This little halfling is dishing out so much damage in a single hit that he's one-shotting frequently. And even if he does get caught, his AC remains decent, if he has Mirror Image up the attack usually hits one of those instead, and he can use his reaction to halve the damage of any attack with Uncanny Dodge. Evasion seems to come up fairly often as well.

Rogues really are pretty awesome.

You must fight lots of low CR creatures if that's one-shotting. Even on crits, that should rarely oneshot due to how 5e bloats hp.

11th level rogue, 20 DEX, +2 rapier, BB/GFB would do d8 weapon, 2d8 spell, +5 DEX, +2 magic, 6d8 sneak. On average, that does 41.5 damage. A CR 3 creature by the CR table, well below punching weight for 11th level, has 101-115 hitpoints. That's enough to soak your average crit. You'd have to roll near max on a crit to one shot, on 18 dice! That's very uncommon -- you have a 4% chance to do this for 101hp, and there's less than a 1% chance to hit 115.

I mean, it's a nice bit of damage, for sure, but your specific experience seems to be dealing with low CR creatures if you're routinely one shotting.

 

[Mistwell]

You must fight lots of low CR creatures if that's one-shotting. Even on crits, that should rarely oneshot due to how 5e bloats hp.

11th level rogue, 20 DEX, +2 rapier, BB/GFB would do d8 weapon, 2d8 spell, +5 DEX, +2 magic, 6d8 sneak. On average, that does 41.5 damage. A CR 3 creature by the CR table, well below punching weight for 11th level, has 101-115 hitpoints. That's enough to soak your average crit. You'd have to roll near max on a crit to one shot, on 18 dice! That's very uncommon -- you have a 4% chance to do this for 101hp, and there's less than a 1% chance to hit 115.

I mean, it's a nice bit of damage, for sure, but your specific experience seems to be dealing with low CR creatures if you're routinely one shotting.

We are 7th level and adventuring in Dungeon of the Mad Mage. I am sure it will not one-shot foes at higher levels but for now it does it fairly often. I think a lot of people enjoy a few "hard" or "deadly" encounters per day for 5e but we're closer to the stated norm from the core books with a lot more encounters in an adventuring day.

My rogue does 1d8+5 (rapier) + 1d8 (Booming Blade) + 4d6 (sneak attack) for an average of 28, and then another 2d8 (9) if the foe moves after the hit. Which sometimes happens if I used the familiar with the help action to grant advantage (or just attacked without advantage and used something else for sneak attack) and used my bonus action to disengage with cunning action and move off, or if our wizard threw a bonfire on their space (which happens often).