RAW, can you use the Sharpshooter and Great Weapon Master feats to make an improvised weapon attack with a longbow?

Question

Occasionally when looking through posts I see people talk about taking Sharpshooter and Great Weapon Master so that they can make an improvised weapon attack with a longbow at -10 to hit +20 damage. Do the rules allow this?

Here is Jeremy Crawford on Twitter saying that it can't be. Whereas here is an answer to another question that uses just the PHB without Sage Advice and says otherwise.

Is there anything in the books that backs Jeremy Crawford's ruling? If so, where in the rules does it say this exactly?

I don't want to just say no due to the "Sage Advice says this" reason because having to look up Sage Advice for rulings constantly for this edition is tiring.

Am I wrong in saying that the rules say:

• This shouldn't work because the Sharpshooter and Great Weapon Master feats say you have to be proficient. And with improvised weapons, you're not proficient unless you have Tavern Brawler.
• Even if you had all three feats, on page 147-148 PHB under "Improvised Weapons", it doesn't say anything about a weapon losing its traits.

The reason I am asking is a player has recently been asking a lot of munchkin questions (new to 5e from 3.5) and I don't wanna say flat-out no without a decent explanation as to why. If I do allow 3 feats to be taken for 1d4+20+Str at 1d20+prof+Str-10 to hit. Statistically, that doesn't sound better than 1d12+10+Str at only -5. But then again he might want the Archery fighting style and a lot of other weird things.

Answer 1

The Sharpshooter feat only affects range attacks

So a longbow hitting in melee would be a improvised melee attack with a ranged weapon. Right?

There is no such thing as "melee attack with a ranged weapon" in 5e. When you smack somebody with a crossbow, you use the crossbow as an improvised weapon. All features requiring a range weapon do not work in this case.

When rules are ambiguous, a DM should use common sense and consider intent behind the rules. Sharpshooter is meant to be used only with ranged weapons. If you use a longbow as an improvised melee weapon, it loses its "ranged" property. This was tweeted by the rules author. Therefore, Sharpshooter only affects range attacks.

As a DM, be more assertive

The reason I am asking is a player has recently been asking a lot of munchkin questions (new to 5e from 3.5) and I don't wanna say flat out no without decent explanation as to why.

The thing is — D&D 5th edition empowers the DM in ways that 3rd, 3.5, and 4th did not. While rule zero has always applied, 5th edition chooses not to explicitly codify many things. If the DM says you can't, you can't.

If you are the DM, and you think that Sharpshooter shouldn't affect melee attacks, all you need to do is saying to your players "In my games Sharpshooter feat only affects shots, not melee attacks".

If a player asks you to back this up with any citation of game text, quote the feat description:

You have mastered ranged weapons and can make shots that others find impossible.

Answer 2

There are a couple reasons why this would not work.

The rule for improvised weapons states:

An object that bears no resemblance to a weapon deals 1d4 damage (the GM assigns a damage type appropriate to the object). If a character uses a ranged weapon to make a melee attack, or throws a melee weapon that does not have the thrown property, it also deals 1d4 damage.

The longbow used as a melee weapon is therefore an improvised weapon, not a ranged weapon. The weapon literally changes type for the attack. Sharpshooter requires a ranged weapon for the attack. Sharpshooter (PHB, p. 170) says:

Before you make an attack with a ranged weapon that you are proficient with, you can choose to take a -5 penalty to the attack roll.

Two, Sharpshooter requires a weapon with which you are proficient and, unless a character has the Tavern Brawler feat (PHB, p. 170), they are not proficient with improvised weapons:

You are proficient with improvised weapons.

Answer 3

Due to way 5e has been worded and built, a strict RAW interpretation regarding whether it can be done would indicate that yes, this is possible.

It doesn't say specifically anywhere that improvised weapons lose the traits or are replaced by only it being improvised.

And outside of flavor text for Sharpshooter, it says nothing about specifically ranged attacks on the -5 to hit +10 to damage.

This is only possible with the Tavern Brawler feat. As such, to do this silly thing as it is put strictly RAW and is easily appealed and ruled against by any DM who isn't just allowing it because it's funny.

This also means thrown greatswords with Tavern Brawler and using a dart in melee with Sharpshooter and Tavern Brawler could also work.

In the end it is up to the DM if they want this kind of play in their campaign, and if they wish to ignore the optional Sage Advice.

Other than using RAI and the DM making a decision when it comes to the rules in the book, this works. But it is not recommended to open that can of worms and look so in-depth into the exact wording of 5e. 5e is meant to be interpreted and read in plain English with reasoning.