Can you use the Poisoner’s Feat with Psychic Blades?

A Soulknife’s Pyschic Blades are part of the Simple Melee weapon category, with Finesse and Thrown properties that manifest as shimmering blades of psychic energy.  

I read on another thread, one asking about the use of the Cunning Strike/Poison feature with Psychic blades, and they supported the idea of using by flavoring the poison as Toxic Thoughts.  Nowhere does it say you can’t, just that it’s part of the Sneak Attack.  I like the way the thread flavored the attack as Toxic Thoughts and that poisons don’t have to be liquid.  

I don’t see anything that says you can’t use poison (from the Poisoners feat) on Psychic Blades.  However, I’ve read articles where the author assumes you can’t due to the physical nature of poisons.  It’s my opinion that you can flavor the use as Toxic Thoughts or Toxic Energy, just like the Cunning Strike/Poison feature.  

Another datapoint, Mages can cast the Ray of Sickness spell that causes poison damage and applies the Poisoned condition on a hit.  

Thoughts?   (preferably not toxic ones)

The Poisoner feat requires a "weapon or piece of ammunition" - and Soulknife is neither. Soulknives also exist only for the moment it takes to make the attack, so there's no time to apply the poison. Cunning Strike is different, since it merely attaches itself to the Sneak Attack and doesn't involve a physical poison at all.

The Psychic Blades are weapons — they're explicitly defined as simple melee weapons — but you're right that they can't be used with the Poisoner feat because they only exist while making an attack with them, and there's no opportunity to use a bonus action to actually apply the poison.

Hmmmmm - grey area.

• One can take an attack action with extra-attack feature (eg Fighter 5) and move between the allowed 2 attacks.
• One can also presumably use the Misty Step bonus action between the two attacks to strike different opponents

Could one then take an attack action, summon your psychic blade, take a bonus action and poison the psychic blade, then attack with it and end your action?

As per the PHB 2024 it says you choose when to take it, no mention of not being during an action or not. So seems legit to do so.

Further - if you miss with your attack is the soul blade still poisoned for 1 minute until you hit? Do you summon the same blade each time or not??

Bonus Actions

Various class features, spells, and other abilities let you take an additional action on your turn called a Bonus Action. The Cunning Action feature, for example, allows a Rogue to take a Bonus Action. You can take a Bonus Action only when a special ability, a spell, or another feature of the game states that you can do something as a Bonus Action. You otherwise don’t have a Bonus Action to take.

You can take only one Bonus Action on your turn, so you must choose which Bonus Action to use if you have more than one available.

You choose when to take a Bonus Action during your turn unless the Bonus Action’s timing is specified. Anything that deprives you of your ability to take actions also prevents you from taking a Bonus Action.

[EDIT] Retracted - see post below [/EDIT]

I wonder if we need to step back a bit.  The Soulknife Rogue uses Psychic energy to manifest his blades, use his knack and telepathy.  What if he also used his Psychic ability to load his blades with toxic energy/thoughts, similar to the magicians Ray of Sickness.  The Poisoned condition now covers a variety of maladies, such as diseases.  What if the Soul Knife's poison is a madness based psychic energy that when delivered, stresses the victim's hold on reality.  

Applying the poison to the blades for the Rogue is effectively loading the blade with creepy thoughts.  

Quote from Jurmondur >>

There's this rule "You can take only one action at a time.", which I feel like is vague and can be interpreted to mean the english definition of action, or pretty much anything you do. If you interpret it as meaning Action, then what is it really telling you? Except for action surge and haste you can only take one Action per turn anyways and would never run into this. Of course, it is subsequently referred to as "This principle...", so it is possible it isn't meant to be a rule at all.

Ahhhh - I concur after actually reading (2024) it properly.

From the BA glossary ... "Various class features, spells, and other abilities let you take an additional action on your turn called a Bonus Action."

So it defines a BA as a type of action.

In Chapter 1 under Actions it has this bit One Thing at a Time which states you can only take one action at a time.

"The game uses actions to govern how much you can do at one time. You can take only one action at a time. This principle is most important in combat, as explained in “Combat” later in this chapter."

So yeah agree with @Jurmondur, being able to only take 1 action at a time then the poisoner feat cannot stack with the psychic blades/soul knives for the Rogue (unless your DM disagrees)

Ahhh, but per the rules, I can apply the Poison condition on a sneak attack with Soul Knives, there is nothing that states otherwise, the language doesn't get into actions or bonus actions, only that I apply toxin to the strike and the only requirement is I have a poisoner's kit.  This implies that my Knives are capable of holding poison.  

Quote from madcar_1 >>

Ahhh, but per the rules, I can apply the Poison condition on a sneak attack with Soul Knives, there is nothing that states otherwise, the language doesn't get into actions or bonus actions, only that I apply toxin to the strike and the only requirement is I have a poisoner's kit.  This implies that my Knives are capable of holding poison.  

 All true but the cunning strike poison option doesn't use an action or BA so it's valid. At the time the blade is manifested it gets (insert fluff description here) and then you strike. All part of the attack ACTION. Valid.But as you can only take 1 action at a time you cannot use a BA to poison them as they have disappeared before your BA starts leaving you looking embarrassed holding a vial of poison and wiping it on ... mid air?