https://www.dndbeyond.com/classes/rogue#SoulknifeUA

I really like the soulknife subclass for the rogue. It looks like it has really cool potential as an infiltrator type rouge, or a flashy stylish combat rouge. I really appreciate the design team's attention to detail, and all the little touches that tie together the flavor and mechanics of the soulknife. For instance, because the soulknife is supposed to be a scary infiltrator type, they specify that

(a). Your soulknives disappear after you attack with them (hit or miss).

(b). They leave no visible injury.

You can imagine that would make for a pretty good assassin. Also for some reason I've always had this niche in my mind for a character that could just keep making throwing weapons and then just throw them all over the place.

But anyway, this is just for general discussion of the soulknife rogue.

I prefer the old soul knife, not the new one. I don't really like the psi die, but the general idea is still very similar. I totally agree with you on your concept.

Quote from OboeLauren >>

Oh hi, Cally the warforged soulknife rogue here!  :D

I completely agree that the soulknife has a lot of spooky, scary potential. Though I have been having fun playing against that type with my character's personality. A friendly, happy character who just happens to be able to turn deadly if necessary has been a fun dichotomy! 

At a low level the most fun aspect for ME has been the psychic whispers feature. While it's most obviously useful when sneaking ahead and relaying information back to the team, just activating it to keep in mental contact during role playing has also been a lot of fun. It's supposed to be one on one communication ("For 1 hour, the chosen creatures can speak telepathically with you, and you can speak telepathically with them.") so often I'll just announce that I'm relaying the conversation between everyone so we can have a more natural conversation. But it's also fun to remember that limitation in the psychic whispers, especially when using it with someone who isn't a member of my party. Nothing like sending a message directly into someone's mind without them knowing who it is or what is happening.

 Huh, I didn't pay much attention to the psychic whispers, but that's just because whenever I look at a new subclass, I tend to gravitate towards looking at the optimal strategies for using the combat related features. But that seems fun, especially in conjunction with the whole invisibility thing for scouting.

It would be fun to try to use deception + psychic whispers to make someone think that what you said to them was their own thought, inception style.

Psi-Bolstered Knack is also extremely powerful when it applies. It takes so many rolls to lose your Psionic Talent die that in practice you have a permanent Bardic Inspiration for your proficient skills and tools. Coupled with Expertise that gives you the potential to hit very high DCs with ease. By 5th level you're looking at +6 from double proficiency and an average of +2.5 to +4.5 depending on die size, and that's before adding your ability modifier.

I could also see psychic teleportation being used for some cool stunts if you want to be flashy. For example, you could throw a knife over a flying creature, and then teleport onto it's back, or you could use it to get trough a trap filled hallway. I've always liked teleporting abilities.

One problem I've noticed about the subclass is that you have to be third level (as per usual), which means it's hard to make a backstory where your powers manifest before you start adventuring (unless your campaign starts at level 3). But I guess that's what they had to do to make it work as a rogue subclass.

also, the 17th level ability seems slightly under-powered.

I absolutely love the Soulknife. I've never played one, but it's so creepy/cool. I like the new Psi Dice mechanic, and the teleportation ability is fun.

Quote from ALinkToTheTacocat >>

One problem I've noticed about the subclass is that you have to be third level (as per usual), which means it's hard to make a backstory where your powers manifest before you start adventuring (unless your campaign starts at level 3). But I guess that's what they had to do to make it work as a rogue subclass.

To be fair the powers you get at 3rd level are pretty powerful (not just mechanically, also in terms of its story implications) and also a bit too complex for a new player (which is the main consideration behind 1st level characters being super simple.)

Unless we're talking Adventurer's League there's nothing stopping a DM from working some minor psionic powers into your background. Of all the dials and levers the game exposes to tailor a character to a player's story, backgrounds are the biggest and also the most underutilized.

And if you really want some tangible benefit at 1st level that's not subject to the DM's creativity you can always go Variant Human and pick the Wild Talent feat. Both benefits are pretty decent for a Rogue.

Luckily for me, I'm playing a (mtof variant, can't remember which) tiefling, so I get minor illusion and can flavor it as psionics. That or high elf or any other race with innate spellcasting is probably the way to go if you want to have a character who always had psionic powers. You could also do variant human with magic initiate.

But I agree that getting soulblade powers from level 1 would be overwhelming to a new player. I don't know about tying psionic powers to your background, but maybe you could flavor a good persuasion, insight, or deception check or two as using psionics to invade someone's mind.

Quote from ALinkToTheTacocat >>

I don't know about tying psionic powers to your background, but maybe you could flavor a good persuasion, insight, or deception check or two as using psionics to invade someone's mind.

It doesn't have to be a significant benefit. Something as minor as casting a cantrip like true strike, message, mage hand, or friends (whichever is most appropriate for the character) with no components once per day would be suitable for a background. Or even something completely ad hoc but trivial like being able to sense an NPC's emotional state.

Yeah, that's probably a good way to do it, but I wonder what people will do if/when it becomes AL legal.

Quote from OboeLauren >>

Oh hi, Cally the warforged soulknife rogue here!  :D

I completely agree that the soulknife has a lot of spooky, scary potential. Though I have been having fun playing against that type with my character's personality. A friendly, happy character who just happens to be able to turn deadly if necessary has been a fun dichotomy! 

At a low level the most fun aspect for ME has been the psychic whispers feature. While it's most obviously useful when sneaking ahead and relaying information back to the team, just activating it to keep in mental contact during role playing has also been a lot of fun. It's supposed to be one on one communication ("For 1 hour, the chosen creatures can speak telepathically with you, and you can speak telepathically with them.") so often I'll just announce that I'm relaying the conversation between everyone so we can have a more natural conversation. But it's also fun to remember that limitation in the psychic whispers, especially when using it with someone who isn't a member of my party. Nothing like sending a message directly into someone's mind without them knowing who it is or what is happening.

Also any one who hasn't had a chance to experience OboeLauren as Cally Zaffrab in action on "Silver and Steel" is missing out, She's a character with more heart than the other characters, (except Sofieus) without actually having a heart. 

Two questions:

1) The knives are referred to as 'magic blades', but is the intention they count as magical attacks? (I read they do)

2) Is there any limit to the size of the psionic talent dice? It isn't explicit that the 'rolling a 1 increases the dice size' is a one time thing and I infer that if I keep rolling '1' it keeps going up in size - can it do all the way (d4 > d6 > d8 > d10 > d12 > d20)?

Any views/semi-official responses appreciated.

Quote from Felix6557>>

1) The knives are referred to as 'magic blades', but is the intention they count as magical attacks? (I read they do)

Yes. From the Basic Rules chapter 12 and Monster Manual Introduction:

Vulnerabilities, Resistances, and Immunities

Some creatures have vulnerability, resistance, or immunity to certain types of damage. Particular creatures are even resistant or immune to damage from nonmagical attacks (a magical attack is an attack delivered by a spell, a magic item, or another magical source). In addition, some creatures are immune to certain conditions.

The blades are magic weapons.

In practice, it doesn't matter, since resistance or immunity to nonmagical attacks only applies to bludgeoning, piercing, and slashing damage 99% of the time. I've yet to see an official monster stat block saying "psychic damage from nonmagical attacks" in its resistances.

2) Is there any limit to the size of the psionic talent dice? It isn't explicit that the 'rolling a 1 increases the dice size' is a one time thing and I infer that if I keep rolling '1' it keeps going up in size - can it do all the way (d4 > d6 > d8 > d10 > d12 > d20)?

The limit is its starting size.

Changing the Die’s Size. If you roll the highest number on your Psionic Talent die, it decreases by one die size after the roll. This represents you burning through your psionic energy. For example, if the die is a d6 and you roll a 6, it becomes a d4. If it’s a d4 and you roll a 4, it becomes unusable until you finish a long rest. Conversely, if you roll a 1 on your Psionic Talent die, it increases by one die size after the roll, up to its starting size.

I remember when this was a prestige class for 3rd Edition. Mainly because I have the psionics handbook for some reason.

Question : At level 3, I want to attack with my rapier as the damage die is higher. After I attack with the rapier, as a bonus action, do I have the option of creating and attacking using a psionic blade in my free hand? And would that be a 1d4? 

"After you attack with the blade, you can make a melee or ranged weapon attack with a second psychic blade as bonus action on the same turn, provided your other hand is free to create it. The damage die of this bonus attack is 1d4, instead of 1d6."

And if the bonus attack with psionic blade is only 1d4, then would duel wielding 2 light melee weapons (2x short swords) would be better? 

You can only make the second attack after you attack with the psychic blade first.

After you attack with the blade, you can make a melee or ranged weapon attack with a second psychic blade as a bonus action on the same turn, provided your other hand is free to create it. The damage die of this bonus attack is 1d4, instead of 1d6.

You are right that the second attack would use a d4.

Dual-wielding shortswords does give you 2 d6 attacks, which could, in some cases, be better than a d4 and a d6. On the other hand, psychic blades deal psychic damage, which almost no creatures have resistance to, while shortswords deal slashing, which many creatures are resistant or immune to. In addition, psychic blades can be thrown with a decent range, providing ranged options. If it matters to you, psychic blades also don't leave a mark on the target, which is great for assassination. Dual-wielding shortswords would not allow you to add your modifier to the damage of the second strike, while Psychic Blades does. This is better than the damage die increasing by a size, especially if you have a high Dexterity modifier.

At higher levels, you get additional benefits for using the blades. Homing strikes allows you to add your psionic talent die to the attack roll. Psychic teleportation lets you move to the blades. Rend mind lets you stun targets that you damage. All of these features require the use of your psychic blades.