I"m making a Barbarian subclass focused on weaponless combat. One of it's class features is that it's unarmed strikes deal 1d6+STR bludgeoning at 3rd level, and 1d8+STR at level 10. How would I properly add these into the homebrew so that they're visible as an attack?

Create the class feature, and then you need to “add action.” For the action itself, you need to fill out these fields:

Action Type: General Weapon
Name: [Subclas] Unarmed Strike (or if you have given that action a specific name, use that instead)
Ability Score Type: Str
Level: 3
Is Proficient: ☑️
Attack Range: Melee
Dice Count: 1
Die Type: d6
Weapon Attack Subtype: (Use Unarmed for punchykickstuffs, or Natural for hornyclawtypestuffs)
Damage Type: Bludgeoning
Display as Attack: Yes
Affected by Martial Arts: ☑️
Activation Type: Action*
Snippet: (A shortshort version of the part of the class feature’s description that specifically pertains to these attacks.**)
Description: (If you leave this blank, the character sheet will automatically default to the main description of the class feature itself.)
[SAVE]

Once you have saved the action and been automatically redirected to the form for the class feature that grants that action, then you will need to specifically edit that brand new action you just created and scroll all the way to the bottom and you will find there is a new section called “Level Overrides.” Hit “Add A Level Override,” and then fill it out like this:

Level: 10
Dice Count: 1
Die Type: d8
[SAVE]

When the website has redirected you to the form for the Action, hit save again, and when it has redirected you to that parent class feature again, you need to hit [SAVE CHANGES]. And then, you will also need to re-save the entire Subclass using the main [SAVE CHANGES] button under “Nasic Information so the system can pick all of that new stuff up. After that, it could take up to 20 minutes for the new action to push through to the character builder/sheets, so just be patient.

I hope that helps.

*If they could potentially dual wield these special unarmed strikes, then you would also need to duplicate this whole process and set the Activation Type for the second one as “Bonus Action.”
**You can learn more about snippets and how to insert special codes to automatically update the “1d6” in the text block for this feature that is vision the character sheet to 1d8 when the character hits 10th level by following this link: https://www.dndbeyond.com/forums/dungeons-dragons-discussion/homebrew-house-rules/25930-using-snippet-codes-in-your-homebrew. You can also ask questions pertaining to those codes there as well, there are some incredibly helpful and knowledgeable folks who hang out in that forum.

Thank you!

I have a similar ability for a subclass I am working on but I can't get the attack to show that the attack roll should use their proficiency bonus AND strength mod. How can I add the strength bonus to the attack roll?

Ability Score Type: STR

Thanks! I had tried that and it didn't work at first but I think it just needed time to refresh on the backend.

I followed exactly what you did above for an unarmed strike that uses the WIS instead of the STR hit/dc. For some reason when I select Ability Score: WIS it won't add my proficiency bonus so says +3 (the amount of my wisdom modifier) instead of +5 (WIS modifier + Proficiency bonus). Is there a modifier I need somehow?

You need to check the “is proficient” box.

Quote from IamSposta >>

You need to check the “is proficient” box.

 I did that.

I also created a modifier since the damage is 1d4+wisdom modifier piercing.
Modifier: Damage Subtype: Piercing Dice Roll: 1d4 Primary stat: WIS

Figured it out. I had scaling in the wrong location and after I deleted it, it worked.

A simpler way, though not exactly the same, would be to have the subclass get the Unarmed fighting style.