Do you add your proficiency bonus if you are not proficient in the skill but you are proficient in the stat?

Question

I have a sorcerer with 10 dex, which is +0 and 16 cha which is +3

So if I make a dex saving throw, I get +0 as I have no proficiency If I make a cha saving throw, I get +3 and since I am proficient in charisma I get my proficiency bonus which is +2

The bit I am struggling with is, if I make a performance (cha) check, which I don't have proficiency in, do I get just +3, or do I get +5 because I am proficient in charisma even if I'm not proficient in performance? Or does that only apply to saving throws?

Likewise if I make a persuasion check and I have persuasion proficiency, is it +5 (+3 and +2 prof. bonus because it doesn't stack twice)?

Answer 1

No. You are never proficient in an ability like Charisma. Sorcerers are proficient in Charisma saving throws, so you add your proficiency whenever you must make a Charisma saving throw.

This proficiency wouldn't apply to a Charisma (Performance) roll, since that's an ability check, not a saving throw. You'd only gain your proficiency bonus on a Performance roll if you had a feature that gave you proficiency in Performance (or proficiency with the tool/instrument being used, or a feature that otherwise applied to the circumstances).

Answer 2

Proficiency in Saving Throws and Proficiency in Skills are Two Different Things

Having proficiency in Charisma saving throws simply means that if your DM ever asks you to make a Charisma saving throw, you get to add your proficiency bonus to that roll. If you want to add your proficiency bonus to a skill, you must be trained/proficient in that skill. You are not automatically trained/proficient in a skill simply because you have proficiency in the saving throws for the governing attribute.

In your above examples, you would have a +3 to your Performance check because you get to add your Charisma modifier always, and you get to add your proficiency bonus only if you are proficient with that skill. Since you said you are not proficient in Performance, then you do not get to add your proficiency bonus.

In your second example, you are correct that your final modifier would be +5. This is because you get to add your Charisma modifier (+3) and, since you are trained/proficient in Persuasion, you also get to add your proficiency bonus (+2).

Answer 3

No, proficiency in Charisma means you get to apply your proficiency bonus to a SAVING THROW involving that attribute. It doesn't mean you are proficient in a skill based on that attribute.

From page 83 of the System Reference Document 5.0

Each class gives proficiency in at least two saving throws. The wizard, for example, is proficient in Intelligence saves. As with skill proficiencies, proficiency in a saving throw lets a character add his or her proficiency bonus to saving throws made using a particular ability score. Some monsters have saving throw proficiencies as well.