so I have a player who has built a Githyanki Barbarian (Stormherald) She’s very into the Gith and was doing research on them and stumbled across the Gith stat blocks as monsters. The Githyanky warriors, I believe, deal 2d6 psychic damage on their first attack or something (honestly, i’ve Never used Gith as monsters). My player read this and asked me why she hadn’t been adding this to her rolls. I told her cause the gith in the monster Manual are trained differently, but she was a little uh hot about it I guess. Any advice? Should I let her add that extra damage? Honestly it wouldn’t set me back too badly, generally my combat scenarios are more focused on achieving a specfic goal then just “Kill all bad guys” 

Just doing some quick research, it appears ( and I'm sure someone will be along to correct me if I'm wrong :D ) that one interpretation is that the Githyanki Warriors do not inflict psychic damage as an innate ability, but as a result of the weapons that they wield.

Silver Swords. In ancient times, gith knights created special weapons to combat their mind flayer masters. These silver swords channel the force of the wielder’s will, dealing psychic as well as physical damage. A githyanki can’t become a knight until it masters the singular discipline needed to will such a blade into existence. A silver sword is equivalent to a greatsword, and takes on the properties of a +3 greatsword in the hands of its creator.

In the eyes of the githyanki, each silver sword is a priceless relic and a work of art. Githyanki knights will hunt down and destroy any non-githyanki that dares to carry or wield a silver sword, reclaiming it for their people.

If I had a Player angling for this, I'd tell them that they can inflict that damage if-and-when they have a Silver Sword. I would also interpret that text as each sword being the singular creation of a trained Githyanki warrior - since they need to "[master] the singular discipline needed to will such a blade into existence." So - until they can will one into existence, they can't do that, and if they steal one, the owner is going to come gunning for them. If they kill someone for theirs - that's a crime which they'd be hunted for.

While it's totally a personal interpretation, I'd probably have these swords dissipate when their creator dies - since it's a manifestation of their will, so you couldn't kill for one anyway. That's totally a homebrew spin on it though.

However, it could be an interesting personal quest for this Character to find a means of learning the skills needed to will one into existence! You could build adventure arcs around that, if that Player wants to become a creator/wielder of such a weapon.

Also:

Outposts in the Mortal Realm. Since creatures that dwell on the Astral Plane don’t age, the githyanki establish creches in remote areas of the Material Plane to raise their young. Doubling as military academies, these creches train young githyanki to harness their psychic and combat abilities. When a githyanki grows to adulthood and slays a mind flayer as part of a sacred rite of passage, it is permitted to rejoin its people on the Astral Plane.

Given that your Player's Character is probably only on the material plane as a young Githyanki, expected to develop her psychic and combat abilities ( how did she end up a Barbarian?! Not impossible, but there's got to be some interesting backstory there! ) and eventually rejoin her race, it wouldn't be impossible for her to learn to do this, I don't think.

However, I'd make this a very high level ability - taking a long time to master, as you're essentially giving them a magic weapon which inflicts double damage.

Just some thoughts :)

All the Gith monsters do deal additional psychic damage with their attacks. But the damage amount varies. And the playable race does not get this bonus (because it would unbalance it).

The monsters do the extra damage to present more of a challenge. Players have class levels to increase their challenge.

If you are fine with your player gaining this psychic damage bonus, make it a feat they have to take. Something like static 1d8 extra psychic damage, and/or they can use a bonus action to empower their next attack with 2d8 psychic damage.

Quote from Vedexent >>

 expected to develop her psychic and combat abilities ( how did she end up a Barbarian?! Not impossible, but there's got to be some interesting backstory there! )

 Pyrokinesis (Desert), cryokinesis (Tundra), or various other forms of psychokinesis (Sea). 

Oh the Silver Sword Idea is cool. Her backstory is that she was a space to the Illithid in the underdark, subject to a life of horrible sadness. And one day during a hunting/gathering job She “snapped” and a blazing fire surrounded her and she blacked out. Once she awoke, she was in the middle of a pile of scortched illithid and Gith bodies. She fled, found her way to Undermountain, where she runs into Volo, who thought she was curious, and takes her under wing. 

I think I’ll tell her that she would need to train with a Gith Blacksmith(silversmith?) And that She must forge the weapon. That would be satisfying I think. 

Thanks for the help guys! 

You're welcome :)

I wouldn't interpret that as needing to learn blacksmithing/forging/silversmithing. Remember - A githyanki can’t become a knight until it masters the singular discipline needed to will such a blade into existence.

To me that implies that the creation of the blade is the result of a direct act of will. She would need to develop the willpower and mental skills that would allow her to create the blade literally out of nothing :) 

That's a lot more nebulous as how to handle it mechanically. I think at the very least she'd need to track down a Githyanki Master ( adventure there ), convince them to train her ( possibly more adventures there as she needs to 'prove herself' ), go through exercises to train her abilities ( adventures here as well ), maybe find the sacred space she needs to do it, and gather the items needed for the ceremony ( guess what that will entail? ), and then will her blade into existence, somewhere around level 16, probably.

But - you can create whatever means that she'll need to create the blade that you like. There's lots of room for DM creativity here.

Have fun!

Seems like you're already happy with the answers you got and know what you want to do, but just to add my two cents, I totally second everything Vedexent has said about the silver swords. The gith are my favorite race in 5th Edition, and I agree with you, Revalow, that working the sword angle into your campaign will be very cool and potentially a lot of fun for you and your player. Much better and ultimately more satisfying than simply saying, okay fine, you can have psychic damage powers. :)

Haha so it’s basically a Gith “Brainblast” Jimmy Neutron style. A cool Idea I’d thought up last night was that the Githyanki knights train in order to  create a kind of Mind Palace if you will. And here they can forge a silvered weapon. And thus the training element is about achieving this internal state requiring some Yoda style training. Which could be fun thing sense she’s a Barbarian. 

Thanks for input ChrisC1066 all the advice I can get is much appreciated. 

Failing all of that, you could also give her some access to Wrathful Smite once a day like some races have access to other spells. Maybe later when she is higher level, bump it up to a Staggering Smite.

Quote from Revalow >>

Haha so it’s basically a Gith “Brainblast” Jimmy Neutron style. A cool Idea I’d thought up last night was that the Githyanki knights train in order to  create a kind of Mind Palace if you will. And here they can forge a silvered weapon. And thus the training element is about achieving this internal state requiring some Yoda style training. Which could be fun thing sense she’s a Barbarian. 

Thanks for input ChrisC1066 all the advice I can get is much appreciated. 

 

That's a really cool idea :)

I realized that the Silver Sword dealing 2d6 psychic damage is really just no more - or less - powerful than a Flame Tongue Longsword.

The MM gith do psychic damage, but they're trained as Gith warriors.  Your player's character is trained as a barbarian, so she gets those features that "regular" gith don't.

That said, it would probably be pretty easy to reskin some of the stormherald abilities to be psychic in nature.  It would  be real easy with a zealot.

Quote from Vedexent >>

I realized that the Silver Sword dealing 2d6 psychic damage is really just no more - or less - powerful than a Flame Tongue Longsword.

 It's a little more power, given how many creatures are resistant or immune to fire damage.

Quote from Generic_Poster >>

Quote from Vedexent >>

I realized that the Silver Sword dealing 2d6 psychic damage is really just no more - or less - powerful than a Flame Tongue Longsword.

 It's a little more power, given how many creatures are resistant or immune to fire damage.

 But you don't get light.  On the other hand, that lets you use stealth.  On yet another hand, I can think of more ways to take damage from dealing psychic damage than from dealing fire damage. 

If your character is traveling with non Githyanki and is a Barbarian, I'm guessing that for whatever reason, they aren't with their Githyanki brethren. Whether the separation was amicable, you can decide, but for Githyanki, I'd guess not. That would also suggest they might not have access to typical Githyanki training methods, such as channeling psychic power into weapons. 

I actually homebrewed a background for Githyanki based on this idea.

I homebrewed (haven't run it past my DM yet...) a Gith Greatsword of Mind Stealing.
Built on a Sword of Life Stealing, of course, but maybe more thematic?

Does typical 2d6+bonus damage, but with a 20 on the attack roll, it does 10 points of psychic damage, and it gives me 10 temporary HP.