Guide:Sharpshooter

Sharpshooter - a guide for a build that focuses on dealing Physical damage from a distance.

Overview

Core components for this build include:

Any kind of Hand Crossbows in each hand
Sharpshooter feat

Sharpshooter provides additional damage for a penalty to accuracy. Attacking from the distance helps to mitigate the accuracy penalty (high ground, hiding) while Hand Crossbows allow to use bonus action to make attacks. Which the bonus damage from Sharpshooter this additional attack more than compensates the fact that Hand Crossbows have less basic damage compared to the Heavy Crossbows.

This build does not require any specific Race or Class. Low mobility is also tolerated. Attacking from a distance allows to put less emphasis on the defence in this build.
As a result this build brings high damage while allowing a lot of options for utility and role-play.

Details

Having minimalistic core this build allows many approaches from the class perspective. The most notable options are:

Battle Master fighter
Hunter ranger
Gloom Stalker ranger + Assassin rogue

Attack count

This build benefits greatly from both: doing multiple attacks for each action and having multiple actions per round.
That's why Fighters, Rangers and Bards are good class choices - all of them get an Extra Attack and can attack twice for the cost of one Action.
There are several ways to get multiple Actions for each turn of the battle with the most notable:

This results in having, on average, 2-3 Actions per turn plus one Bonus action.

Ability Scores

Range weapons use Dexterity as the primary Ability Score so it should be maxed.
Secondary abilities are up to you. Constitution never hurts. For spell casting Rangers might want to improve Wisdom while Bards - Charisma.

Races

This build does not rely on any particular Race.
Halfling is a good choice because of the Lucky. Their low movement speed is less relevant - as a range striker you don't need to move much around battlefield.
Drow with Superior Darkvision is nice in the darker settings.
Dragonborn gets resistance to a damage type - especially useful for Fire damage, which is quite frequent in BG3.

Build variations comparison

Table below compares most notable features each variation brings to the core build. For explanation of numbers and percentages of specific builds see the Math section below

Battle Master version

This version of the build performs great early and mid-game, while completely outperforming other options in the late game.
Action Surge and Manoeuvers provide burst, versatility and additional damage.

Build

Put all your levels into a Fighter.

Get your starting Dex to 16 (or 17 if your are going for a +1 from the Hag).

Get yourself 2 x Hand Crossbows.

Pick an Archery Fighting Style.

At level 3 take the Battle Master subclass.
Select any Manoeuvers you like. Promising options include:

Pick Sharpshooter as your level 4 Feat and toggle the passive on.

As an extra fighter level 6 feat pick Ability Improvement to get Dexterity+2 and bring it to 18 or even 20 (depending on your game choices).

For the feats at levels 8 and 12, you can go with what you like. Some good options include:

Ability Improvement to get your Dex to 20.
Alert to win initiative reliably.
Savage Attacker which will add about 1-3 damage per attack, on average.

Make sure to drink an Elixir of Bloodlust after each long rest.
Getting someone to cast Bless and/or Haste on you will be nice as well.
Enjoy an extremely high damage spread over multiple attacks, all from a relatively safe distance.

Mid-game numbers

Check assumptions in the Math section below.

Overall Battle Master brings about 50% damage increase on top of the core Sharpshooter build.

Archery provides a +2 bonus to Attack rolls you make with ranged Weapons - 10% damage increase.

4 x Superiority Dice provide 4 x 1d8Piercing damage per short rest. This averages to 2 x 4.5Piercing damage per turn, almost 50% of an Attack - about 10% damage increase.

From an extra feat of Ability Improvement having Dexterity+2 will give +5% chance to hit and +1 damage (about +5% damage) - total of 10% damage increase.

For the turn where Action Surge is used, 2 additional Attacks will result in 40% damage increase. Per turn, for a battle, it brings around 20% damage increase.

Late-game numbers

At level 11 you are getting one more Extra Attack now making 3 Attacks for each Action.

Having on average 2.5 Actions per turn will result in 2.5 additional Attacks per turn - about 50% damage increase.

This brings damage of Battle Master version of Sharpshooter on next level, compared to all other version at level 11 and beyond.

Late Heavy Crossbow

The main argument for having Hand Crossbows in each hand is an extra attack on a Bonus action. With level 11, doing 3 Attacks on each Action, you will have on average about 9 Attacks per turn. This warrants switching to a Heavy Crossbow and using your Bonus action for non-attacking purposes.
Heavy Crossbows do, on average, 2 damage more compared to Hand Crossbows. For 9 Attacks this is additional 18 damage which comes close to doing an additional attack on a Bonus action with a Hand Crossbow setup.
For your Action Surge turn this is additional 24 damage which fully equalises with an additional Bonus action attack.

On top of this, Heavy Crossbow will give you a Brace (Ranged) ability.

Even more - now you have your Bonus action free. You can use it for repositioning, getting utility, etc. By this level you should have a lot of items granting you all sorts of additional abilities that require a Bonus action.

Other class options

Beast Master: overall a viable alternative for the Ranger approach.
This subclass does not bring improvements to the range combat hence putting the option into "Other" section. Still beasts are strong and overall Beast Master version will bring both firepower as well as survivability and flexibility to the party.

Champion: an alternative option for the Fighter approach.
Main benefit of this version is an improved critical (equivalent to about 5% overall damage increase). For a ranged build a Champion is more interesting than for a melee one - there are a lot of ways to guarantee crits for melee strikers in bg3. Still Battle Master Manoeuvers provide a comparable damage increase together with a ton of utility and flexibility.
Do note that Champion subclass makes more sense for this build if you try to minimise amount of long & short rests.

College of Valor: an option for a Bard approach.
Brings a full caster in addition to getting 2 attacks (as a ranger or a fighter). Bardic Inspiration brings damage increase comparable to a Battle Master or a Hunter.
The main upside of the Bard approach - ability to utilise Concentration way better. Main downside - bardic inspiration takes a Bonus action to be used, which will make this version of a build doing less damage comparing to some fighter and ranger options.
While having an access to the awesome Bard's spell list is great, with this build you are still usually going to use your Action for attacking with the ranged weapon.

Thief rogue should also be a viable choice (that I have not tested yet)