Rolling for playing an instrument with instrument proficiency, performance proficiency and expertise?

Question

My character has proficiency with an instrument, she also has expertise with in performance. I know the rules say you add and multiple proficiency once.

The RAW for instrument proficiency states

Musical Instrument: Several of the most common types of musical instruments are shown on the table as examples. If you have proficiency with a given musical instrument, you can add your proficiency bonus to any Ability Checks you make to play music with the instrument. A bard can use a musical instrument as a spellcasting focus. Each type of musical instrument requires a separate proficiency.

Expertise states

Your proficiency bonus is doubled for any ability check you make that uses either of the chosen proficiencies.

At first, I questioned if this meant I don't roll a performance check for how well I played my instrument. Similar to how picking a lock has you roll dexterity + proficiency / expertise (but only if you are proficient in thieves tools).

Yesterday me and my GM found two different contradicting Sage Advice answers.

This first link here, states that the GM decides whether they use performance or the tool proficiency, or the DM can allow the player to choose which proficiency to use.

But this second one here, states that the player uses both on the same roll.

They are both written by the same person. The RAW and the Sage Advice tweets from Mike Mearls seem to contradict themselves.

My DM and I tried to figure it out, but neither of us could come up with something that did not seem like making it too effective or too ineffective.

• Using both would mean I could get expertise twice

  We agreed while that'd amount to next to nothing in a combat scenario, on the role play side that would mean my minimum roll at level 3 with a 16 charisma is a 15. It could be argued it balances out since I am only that skilled in that instrument, and it eats up an extra expertise choice.

• Even without that second expertise it is still a minimum roll of 13.

  It kinda makes sense that someone who has put that much effort into their instrument of choice would never preform less than a 10.

When playing an instrument, do you use your instrument proficiency bonus, your performance skill bonus, or both?

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I asked this question a few months back, but it was closed because I could not correctly get across what I was asking about. Now I think I can.

Answer 1

Reference the tool proficiency optional rules from Xanathar's Guide to Everything

You can't apply your proficiency bonus more than once to a single roll, as you've established; it seems like you should probably make this roll using your expertise in performance, since performance is a relevant skill and with expertise that grants you the best modifier. However, there are options to represent your particular combination of proficiencies beyond simply adding more bonuses to the roll.

Xanathar's Guide to Everything, in the Dungeon Master's Tools chapter, includes a section titled Tools and Skills Together, which addresses exactly this situation where a character might have overlapping tool and skill proficiencies. It makes a couple of suggestions about how a DM could adjudicate the situation:

Advantage. If the use of a tool and the use of a skill both apply to a check, and a character is proficient with the tool and the skill, consider allowing the character to make the check with advantage.

[...]

Added Benefit. In addition, consider giving characters who have both a relevant skill and a relevant tool proficiency an added benefit on a successful check. This benefit might be in the form of more detailed information or could simulate the effect of a different sort of successful check.

The chapter then goes on to describe the possible benefits of various tool proficiencies, and gaining advantage on a performance check incorporating that instrument is given as a benefit of proficiency with a musical instrument:

Skills. Every tool potentially provides advantage on a check when used in conjunction with certain skills, provided a character is proficient with the tool and the skill.

[...]

Performance. Your ability to put on a good show is improved when you incorporate an instrument into your act.

An extra benefit to a successful check might perhaps be allowing the bard an automatic success (or at least granting advantage) on a subsequent social skill check to influence the audience after the performance.

The intent of these optional rules from Xanathar's is to make tool proficiencies more valuable, in order to encourage players to take and make use of them as character options, and reward characters who have invested in such specialisation.

Answer 2

You use/apply only one of the proficiency modifiers to a check. Which you use depends on the situation

Which skill you use is up to the DM.

In the event that you have expertise in the Performance skill from being a Bard, then your proficiency modifier for a Performance check is doubled.

For example if you are performing for a crowd then it might make more sense to use your Performance modifier.

But if instead you are practicing/composing a song in your room then it might make more sense to use the Instrument proficiency.

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Are the designers tweets contradictory?

The two tweets are not contradictory, just use slightly confusing wording.

The first tweet ([italicised clarification] mine) :

DM rules which one to use [Instrument or Performance] - or can rule a character can use either, but not both at same time for double bonus

States that you only add one or the other.

The second tweet (emphasis mine)

I'd make that a Performance check and apply double bonus if the bard has Expertise in that skill (PHB, p 54)

Isn't saying that you add both proficiencies. Instead it is saying he would treat the attempt to entertain using an instrument as a performance check and add the relevant proficiency bonus.

If the Bard has chosen one of their expertise choices as Performance then the proficiency bonus is doubled.

So they are consistent.

The rule he is referring to in the second tweet is this one: (PHB pg 54)

EXPERTISE

At 3rd level, choose two of your skill proficiencies. Your proficiency bonus is doubled for any ability check you make that uses either of the chosen proficiencies. At 10th level, you can choose another two skill proficiencies to gain this benefit.

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Does this make instrument proficiency redundant?

This might make it seem like taking proficiency in your instrument is irrelevant, but it isn't.

In a game I was playing in the Bard attempted to use an instrument they were not proficient in to perform.

The DM ruled that the Bard needed to make an Instrument check (with no proficiency bonus) to make sure that they didn't break the unfamiliar instrument/see if they could play it at all.

This was followed by a Performance check to see how well they played it.

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Additional Commentary

The implicit ruling that I've seen, in all games I have played in (or watched online), is that if you are proficient in an instrument/tool then assume you pass the Instrument/Tool check in the example above for checking ability to use the instrument/tool.

Answer 3

As someone who mains a bard most of the time, and DMs, and has a degree in music, let me offer some advice:

1. Proficiency with the tools can be looked at separately from the performance. If you're making a performance, it should be just a Charisma (Performance) check, whereas if you're just playing your instrument, that would be an instrument check.

2. In older editions (or maybe it was home rules), it used to be a +5 to the check. I translate this into my 5e games in a different way.

3. My thought on the matter is that if you try to do a performance without instrument proficiency, you have disadvantage on the roll. I've seen a few times where someone picks up an instrument, doesn't play it that well, but still owns the stage and makes a performance. I've also seen someone with high Charisma bomb a performance because they let self-doubt overcome what they were doing.

Examples:

1. My firbolg fighter has proficiency with pan pipes from home as an outlander. He may sit in the back corner and play the pipes to soothe his nerves in the crowded pub. I'd roll and add my proficiency bonus (no ability, just proficiency added) to the role play. He's not trying to grab attention or be the center, he's just playing. High roll - he lost himself in the music and his haunting tune captivated the tavern. Medium roll - he was good enough to calm his nerves, and no one noticed. Low roll - he couldn't shake his nerves that night and ran out with everyone booing him.

2. My dragonborn bard is playing the tavern and doing well, making his Charisma (Performance) checks without disadvantage because he's using his accordion. Someone hands him a fife and asks for a tune. He then tries to make another Charisma (Performance) check, this time with disadvantage because he doesn't know the instrument that well. He may still own it (maybe he didn't play the right tune, but was within the chord structures to still make a good song), or maybe he biffs it, the instrument being to foreign in his hands and the crowd's pressure got to him.

These are in no way fastened rules, but just some ideas to go off of.