Trying desperately to figure out how to homebrew a feat that allows the following:

"When not wearing armor, calculate your AC as X + your DEX modifier".

So far I have not found a way to force the system to NOT add this equation to the standard unarmored AC of 10 + DEX... I keep coming out with an unarmored AC in the 20s.

Whatever your “X” value is, subtract 10 from it. And stop adding the Dex, it’s automatically calculated in unless you specifically tell it to not include Dex.

Thank you.

How would you exclude DEX from being calculated in that?  For example if you want AC 13 + INT?

You need two modifiers:

• Modifier: Set->Subtype: Unarmored Armor Class->Ability Score: Intelligence->Fixed Value: 3
• Modifier: Ignore->Subtype: Unarmored Dex AC Bonus

The first one makes the AC Calculation 13+Int+Dex, the second one makes it drop the Dex.

Thank you!

Happy to help.

Another question in that direction:

What if I want the AC of for example a set of robes to be 10+ your spell casting ability modifier?

Quote from eyeflash >>

Another question in that direction:

What if I want the AC of for example a set of robes to be 10+ your spell casting ability modifier?

 
Provided you know what the spellcasting Ability is, see the Subclasses & Races FAQ #9: (https://www.dndbeyond.com/forums/dungeons-dragons-discussion/homebrew-house-rules/131411-a-homebrewers-how-to-faq).

That is so helpful. I kept putting fixed at 13 thinking that would put the unarmored at 13 and the AS as Dex thinking it would add the +3 from their dex.

I hope this is the right place for my question. I want to build a leather armor that ignores the dex bonus to ac and instead uses the cha bonus.
Until now I tried the following:

Basic Information -> Base Armor: Leather -> Dex Bonus: None
Modifiers -> Modifier Type: Bonus -> Modifier Subtype: Armor Class -> Ability Score: Cha 
Doesn't work.

Adding "Modifiers -> Modifier Type: Ignore -> Modifier Subtype: Unarmored Dex AC Bonus" doesn't help, I think the "Modifier Subtype: armored Dex AC Bonus" is missing.

Try these:

• Modifier: Set->Subtype: AC Max Dex Armored Modifier->Fixed Value: 0
• Modifier: Bonus->Subtype: Armored Armor Class->Ability Score: Cha

After adding those modifiers, don’t forget to re-save the whole magic item.

Thanks for the fast reply, but it still doesn't work.

Please see the General Homebrew FAQ #6: (https://www.dndbeyond.com/forums/dungeons-dragons-discussion/homebrew-house-rules/131411-a-homebrewers-how-to-faq).

• Modifier: Set->Subtype: Unarmored Armor Class->Fixed Value: 8
• Modifier: Ignore->Subtype: Unarmored Dex Natural AC Bonus

That combination of Modifiers should do the trick.

Quote from Burril >>

I hope this is the right place for my question. I want to build a leather armor that ignores the dex bonus to ac and instead uses the cha bonus.
Until now I tried the following:

Basic Information -> Base Armor: Leather -> Dex Bonus: None
Modifiers -> Modifier Type: Bonus -> Modifier Subtype: Armor Class -> Ability Score: Cha 
Doesn't work.

Adding "Modifiers -> Modifier Type: Ignore -> Modifier Subtype: Unarmored Dex AC Bonus" doesn't help, I think the "Modifier Subtype: armored Dex AC Bonus" is missing.

Don't use armor as the base item, use a wondrous item. Base armor will always add Dex to AC.

Quote from Mairondil >>

Quote from Burril >>

I hope this is the right place for my question. I want to build a leather armor that ignores the dex bonus to ac and instead uses the cha bonus.
Until now I tried the following:

Basic Information -> Base Armor: Leather -> Dex Bonus: None
Modifiers -> Modifier Type: Bonus -> Modifier Subtype: Armor Class -> Ability Score: Cha 
Doesn't work.

Adding "Modifiers -> Modifier Type: Ignore -> Modifier Subtype: Unarmored Dex AC Bonus" doesn't help, I think the "Modifier Subtype: armored Dex AC Bonus" is missing.

Don't use armor as the base item, use a wondrous item. Base armor will always add Dex to AC.

 
Just as a general heads-up, while your post is absolutely informative, 100% correct, and beautifully well illustrated (as all your posts tend to be), that post you responded to was from almost half a year ago. If they still need that solution after all this time I’d be amazed.

I know. I saw the recent exchange and scrolled up and saw earlier comments weren't completely addressed.

I know it's a hack, but it's a specific hack.

I do wonder though if some changes can be made to heavy armor that do something similar since it doesn't account for Dex either. Hmmm I wonder Initial tests are not looking promising.