So.  Sneak attack requires a finesse weapon and does the weapon's damage.  Arcane Trickster can get Wizard spells.  Therefore, Arcane Trickster can cast shadow blade, sneak attack, and deal massive psychic damage every turn.  Is there anything I missed with this?  An Arcane Trickster can get shadow blade at as early as 7th level, since it is an illusion spell, which doesn't eat into spells known of any school, and only requires a 2nd level spell slot.

This seems like one of those "too good to be true" synergies. Someone is going to tell us that you can't sneak attack with a melee spell attack, I bet.

Thing is, it's not a spell attack, it creates a weapon that you can make weapon attacks with.

yes an arcane trickster can sneak attack with the shadow blade for massive psychic damage... all legal and up front from every aspect of the rules... RAW, RAI, ROC, and even the creators wanted it this way... so no prob

Yeah, probably will never get to do it, but was just an interesting idea that I had.

Hope you've had a great day!

If you want, get the Green Flame Blade from whatever source, and add that to your single swing as a Rogue.

Just don't get hit...Shadow Blade is a concentration spell.

And if the psychic blade has a physical shell, apply poison to it for even more damage.

Sorry, could you explain that?  This is an illusory blade made by a spell, right?  What is this 'shell' that we're talking about?

Some illusions have solidity, if the blade is one of these then you can apply poison, if it isnt, you cant. It seems unlikely as it deals psychic damage but it also attacks as a physical weapon requiring you pierce armour with strength or dexterity, implying physical factors are involved. Your DM will let you know either way. Probably a no, but then most people get scared about what poison can add to a fight without considering how much it costs to use.

edit for spelling and this next bit!

Oh when you drop the blade or throw it, The implication is you can pick it up again if quick, this implies it doesnt simply fall through the earth again implying a physical state or a shared illusion or mental shaping the planet shares.

Oooohhhh.  I didn't know what you meant by shell.  Yeah, it's kinda weird, but I guess RAW you can apply poison to it as long as it exists, but RAI... Idk.

Quote from Nthal >>

If you want, get the Green Flame Blade from whatever source, and add that to your single swing as a Rogue.

Just don't get hit...Shadow Blade is a concentration spell.

 That sounds great!  And even better since that and Booming Blade are from the wizard spell list, which AT gets!  The only problem I could see with it is there's no way to do it while hiding, since it requires Verbal components.

Quote from Yharim >>

Quote from Nthal >>

If you want, get the Green Flame Blade from whatever source, and add that to your single swing as a Rogue.

Just don't get hit...Shadow Blade is a concentration spell.

 That sounds great!  And even better since Green Flame is from the wizard spell list!  The only problem I could see with it is there's no way to do it while hiding, since it requires Verbal components.

 Be a ghostwise halfling? Shout your completely telepathic to one person vocals, no one can hear you!

Quote from Moondruidsneversleep >>

 

Quote from Yharim >>

Quote from Nthal >>

If you want, get the Green Flame Blade from whatever source, and add that to your single swing as a Rogue.

Just don't get hit...Shadow Blade is a concentration spell.

 That sounds great!  And even better since Green Flame is from the wizard spell list!  The only problem I could see with it is there's no way to do it while hiding, since it requires Verbal components.

 Be a ghostwise halfling? Shout your completely telepathic to one person vocals, no can hear you!

 Uh, does that work?  Sorry if I'm a bit skeptical, but the page with components in the PHB says that verbal components requires certain sounds, and even if you could, who would not hear a burst of flame or thunder flare up on a sword?

I would say no to the ghostwise.  That's communication not spell casting.

But no need.  Striking from hidden while casting GFB is viable.  Its the equivalent of saying "Surprise <<Humorous censoring bit>>"  you lose hiding on the attack, hit or miss anyway as the verbal is part of the attack.   (That's how I read it).

Oh on the poison bit;  sure if you want to waste the turn on it.  But since the blade dissipates after a throw or drop IF you don't manually pick it up, you probably lose the poison in that case.  I'm not convinced on the value at higher levels due to con saves, but I don't know the math.

That could work.  I'm just imagining a 20th level AT doing this.  "I deal 4d8 + 5 + 20d6 Psychic damage because I crit.  Plus the person next to them takes 4d8 fire damage."  Hilarity ensues as you one hit the boss with psychic damage.

Also, wouldn't there be more potent poison at higher levels?

Quote from Yharim >>

Also, wouldn't there be more potent poison at higher levels?

 There are.  But it doesn't seem to scale as fast your opponents CON.  I would need to look at the math and see if and what poisons are worth it.

But just applying it, you lose 1 round of attacks out of 10.  Another math exercise on if it is worth it.

Yeah, poison probably wouldn't be the best unless you are an assassin targeting a king or some other weak humanoid.  And then, why and how on earth would you use a shadow blade for it?  Poison should become more practical.  Maybe there should be a magical poison that lasts forever or until the weapon is destroyed.

P.S.  There is no reason to do the math on poison.  I wasn't really interested in it.

If you are a thief subclass you gain use object as a bonus action, you would need to learn how to apply poison safely (poison kit proficiency) but after that you dont have to give up a turn - alternatively and more immediately as an arcane trickster you could use your mage hand to apply it. (as manipulating it is a bonus action) In that case you dont have to worry so much about accidental poisoning - your mage hand might get a bit damp though.

On a crit at 20th (non assassin) you would deal 20d6 sneak (10d6 doubled) you can only do 6d8 psychic as thats 3d8 (max 4th level spell slot) and if green flame blade was applied as well another 6d8 (3d8 doubled from the crit.) and at 2000 gold a dose for one whole hit, purple worm poison (most potent injury poison by dmg) 24d6 (double 12d6) but a con save for 1/2

Totalled 44d6+6d8 (however a con 19 reduces the damage to only 32d6+6d8) Crits double all dice rolled but never just flat numerical damage. 181 average damage if no save made, although check the math on that. (oh if a diviner is your friend they can make that con save fail on most days with the letter d in them)

Quote from Moondruidsneversleep >>

If you are a thief subclass you gain use object as a bonus action, you would need to learn how to apply poison safely (poison kit proficiency) but after that you dont have to give up a turn - alternatively and more immediately as an arcane trickster you could use your mage hand to apply it. (as manipulating it is a bonus action) In that case you dont have to worry so much about accidental poisoning - your mage hand might get a bit damp though.

On a crit at 20th (non assassin) you would deal 20d6 sneak (10d6 doubled) you can only do 6d8 psychic as thats 3d8 (max 4th level spell slot) and if green flame blade was applied as well another 6d8 (3d8 doubled from the crit.) and at 2000 gold a dose for one whole hit, purple worm poison (most potent injury poison by dmg) 24d6 (double 12d6) but a con save for 1/2

Totalled 44d6+6d8 (however a con 19 reduces the damage to only 32d6+6d8) Crits double all dice rolled but never just flat numerical damage. 181 average damage if no save made, although check the math on that. (oh if a diviner is your friend they can make that con save fail on most days with the letter d in them)

 Just a quick note, I don't think crits increase Green Flame at all, because it is not part of the attack, it just causes another person to take fire damage.  Otherwise this looks correct.