D&D 5E How powerful is substituting Proficiency Bonus for ability modifier?

[Quartz]

I'm thinking along the lines of the Battlemaster Fighter or Monk here. Call it the Disciplined Warrior. At some point, perhaps instead of getting Indomitable, the Fighter gets the ability to substitute their Proficiency Bonus for any ability modifier 1 or 2 per Short Rest, at will and for one roll only or to the end of the round (note, not the end of the Fighter's turn), whichever comes first. So the PB +4 Int 10 Fighter could apply that +4 to their Int save if they were attacked by an Intellect Devourer. It would not just apply to saves but anything. E.g. a low-Cha PC could apply it to a social roll. Or even a low-Dex fighter having to pick up a bow. To prevent multiclassing cheese you'd have to limit the bonus to the lower of the PB or levels in the fighter class.

Or perhaps this might be better as a Feat?

 

[GMforPowergamers]

Where I don't know that I would allow a feature of some kind like that

 

[Maxperson]

I'm thinking along the lines of the Battlemaster Fighter or Monk here. Call it the Disciplined Warrior. At some point, perhaps instead of getting Indomitable, the Fighter gets the ability to substitute their Proficiency Bonus for any ability modifier 1 or 2 per Short Rest, at will and for one roll only or to the end of the round (note, not the end of the Fighter's turn), whichever comes first. So the PB +4 Int 10 Fighter could apply that +4 to their Int save if they were attacked by an Intellect Devourer. It would not just apply to saves but anything. E.g. a low-Cha PC could apply it to a social roll. Or even a low-Dex fighter having to pick up a bow. To prevent multiclassing cheese you'd have to limit the bonus to the lower of the PB or levels in the fighter class.

Or perhaps this might be better as a Feat?

It's not going to break things and would give the fighter some extra needed oomph outside of combat. If you're doing it per short rest, I'd limit it to once. If it's per long rest, then 2 or 3 times would be okay.

 

[Horwath]

@Quartz

I'm thinking of trying a variant where you add proficiency modifier instead of ability modifier on everything that is not a ability check.

So, attacks, damage, DCs, saves.
Where you are proficient, you add twice your proficiency bonus.

 

[jgsugden]

It is not problematic from a balance standpoint, but it has to make sense. Why does a fighter suddenly have more training in a knowledge based intelligence skill at that brief moment? Why do they suddenly get faster for a brief moment? Why do they suddeny become more charismatic?

This seems like the tail wagging the dog. We're looking at a mechanic and then trying to fit it into a class instead of thinking of an ability that would thematically exist and then coming up with the balanced mechanic for it.

 

[Undrave]

It's not going to break things and would give the fighter some extra needed oomph outside of combat. If you're doing it per short rest, I'd limit it to once. If it's per long rest, then 2 or 3 times would be okay.

Proficiency bonus times per day

 

[Quartz]

Why does a fighter suddenly have more training in a knowledge based intelligence skill at that brief moment?

The fluff would be that the PC is pulling on experience, focus, or (for saves) sheer stubbornness as appropriate. You could call it "Taking a deep breath." or "Stopping and thinking." or "A flash of inspiration."

 

[ART!]

I think if it's something the character might have an unreliable knack for because of their background, that makes sense; a soldier might have a poor CHA, but once in a while can haggle with the best of them over armor prices.

 

[NotAYakk]

I'd find it an awkward mechanic.

Basically it is +X but with a -Y which depends on the roll.

If you compare with flash of genius, which is just a +X.

The difference is that here, it works better on things you are worse at, and worse at things you are better at. Except this only applies to one dimension of what makes you good at something; ability or innate talent, not proficiency.

A cleaner way to make that work would be "substitute a con save for a different save". This has the advantage of not having the -Y.

Another way would be to just gain proficiency. Here, again, we are +X with no -Y, as half proficiency is rare, so you'll only do this when you lack proficiency in the first place.

Simpler math, similar narrative and mechanical effects.

 

[ad_hoc]

I don't like the idea of using indomitable for it.

I actually think indomitable should be like a legendary save where it just succeeds (could require to use before the roll to make it a bit weaker than a legendary save).

As for making up for weaknesses with PB I don't like it as I find low stats to be part of their character.