So a soulblade throws it's phy blade knife at a monk.

A) can the monk use deflect missiles?

B) if the damage is reduced to 0 can the monk throw it back?

A)Yes, thrown blades are ranged weapon attacks.

B)No, the blades disappear immediately after hit or miss (which this would be a hit).

Might this not be a case of specific beating general and the monk intercepting the blade and subsequently being allowed to throw it being the specific that beats the general of the blade disappearing immediately?

Psychic Blades do say they disappear the instant they hit or miss - but Deflect Missiles say you can throw it back as part of the same Reaction used to catch the item - and a Reaction is "an instant response to a trigger of some kind". So mechanically they are both instantaneous effects. I think in that case iirc - it's the creature whose turn it is that gets to choose which happens first - isn't it?

@DxJxC With deflect missile it is not a miss or a hit so based on that would it change your opinion?

Quote from coachmanak >>

@DxJxC With deflect missile it is not a miss or a hit so based on that would it change your opinion?

The condition for being able to use Deflect Missiles is being hit by a ranged attack - so it does still count as a hit for the Rogue - even if the Monk manages to deflect all of the damage.

Quote from Emmber >>

Psychic Blades do say they disappear the instant they hit or miss - but Deflect Missiles say you can throw it back as part of the same Reaction used to catch the item - and a Reaction is "an instant response to a trigger of some kind". So mechanically they are both instantaneous effects. I think in that case iirc - it's the creature whose turn it is that gets to choose which happens first - isn't it?

 And psychic blades only being usable with the rogue's action led me to the conclusion that they disappear before they can be thrown back (since disappear and deflect have the same trigger).

Quote from Emmber >>

Quote from coachmanak >>

@DxJxC With deflect missile it is not a miss or a hit so based on that would it change your opinion?

The condition for being able to use Deflect Missiles is being hit by a ranged attack - so it does still count as a hit for the Rogue - even if the Monk manages to deflect all of the damage.

 "If you reduce the damage to 0, you can catch the missile if it is small enough for you to hold in one hand and you have at least one hand free. If you catch a missile in this way"

(So I'm playing devil's advocate because I agree with both calls, and wanting to see what others think about both sides.)

So allow me to give how I see deflect missile this in my head, missle is sent to a normal person it hits and penetrates, but deflect missle let's the monk catch it as it is going in, therefore reducing damage.  So when it is reduced to 0 the missle does not enter the skin, therefore it's not a hit.

Quote from coachmanak >>

Quote from Emmber >>

Quote from coachmanak >>

@DxJxC With deflect missile it is not a miss or a hit so based on that would it change your opinion?

The condition for being able to use Deflect Missiles is being hit by a ranged attack - so it does still count as a hit for the Rogue - even if the Monk manages to deflect all of the damage.

 "If you reduce the damage to 0, you can catch the missile if it is small enough for you to hold in one hand and you have at least one hand free. If you catch a missile in this way"

(So I'm playing devil's advocate because I agree with both calls, and wanting to see what others think about both sides.)

So allow me to give how I see deflect missile this in my head, missle is sent to a normal person it hits and penetrates, but deflect missle let's the monk catch it as it is going in, therefore reducing damage.  So when it is reduced to 0 the missle does not enter the skin, therefore it's not a hit.

 But the very first sentence of the ability describes the trigger which must happen first for the feature to even be used:

you can use your reaction to deflect or catch the missile when you are hit by a ranged weapon attack.

Quote from Emmber >>

Psychic Blades do say they disappear the instant they hit or miss - but Deflect Missiles say you can throw it back as part of the same Reaction used to catch the item - and a Reaction is "an instant response to a trigger of some kind". So mechanically they are both instantaneous effects. I think in that case iirc - it's the creature whose turn it is that gets to choose which happens first - isn't it?

I agree. And so it can happen both ways depending on the context.

Scenario 1: The Rogue throws the weapon on its turn, the damage is reduced to 0 and the blade disappears.

Scenario 2: The Rogue readies its action throwing the blade on the Monk's turn. The Monk reduces the damage to 0 and throws back the blade.

Scenario 3: The Rogue readies its action to throw its blade at the Monk as soon as he's visible. The Monster drags the Monk out from cover so it can properly enjoy its meal. The Rogue throws its blade at the Monk and the game breaks down as the Monster goes "eh?".

Quote from DxJxC >>

Quote from Emmber >>

Psychic Blades do say they disappear the instant they hit or miss - but Deflect Missiles say you can throw it back as part of the same Reaction used to catch the item - and a Reaction is "an instant response to a trigger of some kind". So mechanically they are both instantaneous effects. I think in that case iirc - it's the creature whose turn it is that gets to choose which happens first - isn't it?

 And psychic blades only being usable with the rogue's action led me to the conclusion that they disappear before they can be thrown back (since disappear and deflect have the same trigger).

Yea - I can't imagine a Rogue on their turn allowing a Monk to throw their blades back at them - but they could have held their action as BeyondMisty pointed out - so the answer could very situationally be a Yes to the original question B.

Quote from ArntItheBest >>

I think that this more boils down to whether or not the blade could be caught. It is a psychic blade that is manifested by the rogue, so I would argue that it is not something that could be caught and thrown back.

This may lead to a discussion on whether or not the monk could even deflect them, but that would be a pretty hard nerf to the monk ability.

It's a weapon attack, not a spell attack, so it physically exists well enough for a monk to deflect it.  Deflect Missiles doesn't work, by contrast, against Ice Knife.