The Gunsmith (credit: 3BH "Outlaws and Obelisks")

Artificer subclass created by Jeremy Cobb and Jasper William Cartwright from the Three Black Halflings podcast for their "Outlaws and Obelisks" campaign.

Modded-out Equalizer

At Level 5 you gain proficiency with firearms and can even fashion your own. As part of a long rest, you can turn a non-magical firearm into your Custom Firearm, which can take the form of either the Peacemaker (handgun) or Boomstick (long gun). You can retool your Custom Firearm as part of a long rest, allowing you to switch between the Peacemaker and the Boomstick.

The Peacemaker does 1d10 piercing damage, has a reload score of 6, a misfire score of 1, has 60/240 range, and grants you advantage on Initiative rolls.

The Boomstick does 1d12 piercing damage, has a reload score of 4 and a misfire score of 2, the range is 80/320.

When you attack with your Custom Firearm, you can use your Intelligence modifier, instead of your Strength or Dexterity modifier, for the attack and damage rolls. The damage from your Custom Firearm counts as magical for the purpose of overcoming resistance and immunity to non-magical attacks and damage.

Arcane Munitionist

At Level 3, your technological mastery allows you to upgrade to technologically enhance your Custom Firearm in a variety of ways. You can learn 3 upgrades. You can only use 1 upgrade die per attack if the upgrade involves an attack, you must choose to use it when you make the attack.

You learn 1 additional upgrade of your choice at 7th, 10, and 15th level. Each time you learn an upgrade, you can also replace one upgrade you know with a different one.

Upgrade Dice. You have four upgrade dice, which are d6s. An upgrade die is expended when you use it. You regain all of your expended upgrade dice when you finish a short or long rest. You gain another upgrade die at 7th level and one more at 15th level. Your upgrade dice also increase in size to a d8 at Level 10 and 1d10 at Level 18

Saving Throws. Some of your upgrades require your target to make a saving throw to resist the upgrade’s effects. The saving throw DC is calculated as follows:

Upgrade save DC = 8 + your proficiency bonus + your Intelligence modifier

Upgrades

Armor Piercing: Every creature in a line 30 feet long and 5 feet wide must make a Dexterity saving throw. The first creature to fail takes damage plus upgrade die damage, and every subsequent creature who fails takes damage equal to the number rolled on the upgrade die.

Assassin Round: Deals poison damage and forces the target to make a Constitution saving throw or be poisoned until the end of their next turn. You can also add the number rolled on the upgrade die to the damage of the attack.

Brandish: Lets you add the damage from the upgrade die to the damage of the attack and forces the target to make a Wisdom saving throw or be frightened of you until the start of your next turn

Concussive Round: Deals force damage and forces the target to succeed on a Constitution saving throw or be stunned until the start of their next turn or until they next take damage. You can also add the number rolled on the upgrade die to the damage of the attack.

Corrosive Round: Deals acid damage and the target's AC is reduced by 1 until the start of their next turn. You can also add the number rolled on the upgrade die to the damage of the attack.

Deadeye: Lets you aim the shot, cutting your movement in half and adding the number rolled on the upgrade die to the attack roll and damage.

Explosive Round: Every creature within 5 feet of the target (including the target) must succeed on a Dexterity saving throw or take bludgeoning damage equal to the number rolled on the upgrade die.

Flaming Round: Deals fire damage and lights the target on fire. They must use an action to put themselves out or take fire damage qual to half the number rolled on the upgrade die at the start of each of their turns (minimum of 1). You can also add the number rolled on the upgrade die to the damage of the initial attack.

Flashbang: Deals radiant damage and forces the target to succeed on a Constitution saving throw or subtract the number on the upgrade die from their next attack roll. You can also add the number rolled on the upgrade die to the damage of the attack.

Flechette: Deals slashing damage and the target must succeed on a Constitution saving throw or take necrotic damage equal to the number rolled on the upgrade die at the start of each of their turns. A target can repeat the Constitution saving throw at the end of their turn, ending the effect on a success. You can also add the number rolled on the upgrade die to the damage of the initial attack.

Frozen Round: Deals cold damage and the target's speed is halved until the start of their next turn. You can also add the number rolled on the upgrade die to the damage of the attack.

Grappling Hook: Forces the target to make a Strength saving throw or be pulled towards you by a number of feet equal to 5 x the number rolled on the upgrade die. The range is limited to how much rope you have. You can also add the number rolled on the upgrade die to the damage of the attack.

Lightning Round: Deals lightning damage and the target takes half the upgrade die damage the next time they touch metal. You can also add the number rolled on the upgrade die to the damage of the attack.

Lone Ranger: The target must make a Strength saving throw or drop one item of your choice that they're holding. You can also add the number rolled on the upgrade die to the damage of the attack.

Net: Large or smaller creature must make a Dexterity saving throw or be restrained. They can use an action to repeat the saving throw on each of their subsequent turns, escaping on a success. You can also add the number rolled on the upgrade die to the damage of the attack.

Quickdraw: At the top of the round, you can use your reaction jump forward in the initiative order by the number you roll on the upgrade die, you return to your original spot after that turn.

Ricochet: Lets you ignore half cover, treat 3/4 cover like half cover, and full cover as 3/4 cover. The target must be within range of the weapon You can also add the number rolled on the upgrade die to the damage of the attack.

Sapping Round: Deals necrotic damage and the target must succeed on a Constitution saving throw or subtract the number on the upgrade die from their next saving throw before the start of their next turn.

Slug: Deals bludgeoning damage and the target must make a Str save or be knocked prone. You can also add the number rolled on the upgrade die to the damage of the attack.

Snub Nose: Lets you shorten the muzzle, allowing you to add the number rolled on the upgrade die to your Sleight of Hand check to conceal your Custom Firearm.

Thunderstruck: Deals thunder damage and the target must succeed on a Constitution saving throw or be knocked back a number of feet equal to the 5+the number rolled on the upgrade die and deafened until the start of their next turn. You can also add the number rolled on the upgrade die to the damage of the attack.

Tracer Round: The number on the upgrade die gets added to the next attack roll against the target. You can also add the number rolled on the upgrade die to the damage of the initial attack.

Armor Piercing

Every creature in a line 30 feet long and 5 feet wide must make a Dexterity saving throw. The first creature to fail takes damage plus upgrade die damage, and every subsequent creature who fails takes damage equal to the number rolled on the upgrade die.

Assassin Round

Deals poison damage and forces the target to make a Constitution saving throw or be poisoned until the end of their next turn. You can also add the number rolled on the upgrade die to the damage of the attack.

Brandish

Lets you add the damage from the upgrade die to the damage of the attack and forces the target to make a Wisdom saving throw or be frightened of you until the start of your next turn

Concussive Round

Deals force damage and forces the target to succeed on a Constitution saving throw or be stunned until the start of their next turn or until they next take damage. You can also add the number rolled on the upgrade die to the damage of the attack.

Corrosive Round

Deals acid damage and the target's AC is reduced by 1 until the start of their next turn. You can also add the number rolled on the upgrade die to the damage of the attack.

Deadeye

Lets you aim the shot, cutting your movement in half and adding the number rolled on the upgrade die to the attack roll and damage.

Explosive Round

Every creature within 5 feet of the target (including the target) must succeed on a Dexterity saving throw or take bludgeoning damage equal to the number rolled on the upgrade die.

Flaming Round

Deals fire damage and lights the target on fire. They must use an action to put themselves out or take fire damage qual to half the number rolled on the upgrade die at the start of each of their turns (minimum of 1). You can also add the number rolled on the upgrade die to the damage of the initial attack.

Flashbang

Deals radiant damage and forces the target to succeed on a Constitution saving throw or subtract the number on the upgrade die from their next attack roll. You can also add the number rolled on the upgrade die to the damage of the attack.

Flechette

Deals slashing damage and the target must succeed on a Constitution saving throw or take necrotic damage equal to the number rolled on the upgrade die at the start of each of their turns. A target can repeat the Constitution saving throw at the end of their turn, ending the effect on a success. You can also add the number rolled on the upgrade die to the damage of the initial attack.

Frozen Round

Deals cold damage and the target's speed is halved until the start of their next turn. You can also add the number rolled on the upgrade die to the damage of the attack.

Grappling Hook

Forces the target to make a Strength saving throw or be pulled towards you by a number of feet equal to 5 x the number rolled on the upgrade die. The range is limited to how much rope you have. You can also add the number rolled on the upgrade die to the damage of the attack.

Lightning Round

Deals lightning damage and the target takes half the upgrade die damage the next time they touch metal. You can also add the number rolled on the upgrade die to the damage of the attack.

Lone Ranger

The target must make a Strength saving throw or drop one item of your choice that they're holding. You can also add the number rolled on the upgrade die to the damage of the attack.

Net

Large or smaller creatures must make a Dexterity saving throw or be restrained. They can use an action to repeat the saving throw on each of their subsequent turns, escaping on a success. You can also add the number rolled on the upgrade die to the damage of the attack.

Quickdraw

At the top of the round, you can use your reaction jump forward in the initiative order by the number you roll on the upgrade die, you return to your original spot after that turn.

Ricochet

Lets you ignore half cover, treat 3/4 cover like half cover, and full cover as 3/4 cover. The target must be within range of the weapon You can also add the number rolled on the upgrade die to the damage of the attack.

Sapping Round

Deals necrotic damage and the target must succeed on a Constitution saving throw or subtract the number on the upgrade die from their next saving throw before the start of their next turn.

Slug

Deals bludgeoning damage and the target must make a Str save or be knocked prone. You can also add the number rolled on the upgrade die to the damage of the attack.

Snub Nose

Lets you shorten the muzzle, allowing you to add the number rolled on the upgrade die to your Sleight of Hand check to conceal your Custom Firearm.

Thunderstruck

Deals thunder damage and the target must succeed on a Constitution saving throw or be knocked back a number of feet equal to the 5+the number rolled on the upgrade die and deafened until the start of their next turn. You can also add the number rolled on the upgrade die to the damage of the attack.

Tracer Round

The number on the upgrade die gets added to the next attack roll against the target. You can also add the number rolled on the upgrade die to the damage of the initial attack.

Semi-Automatic

At 5th level you can attack twice, instead of once when you take the attack action on your turn. 

In addition, the maximum number of items you can infuse at once increases by 1, but that extra item must be your Custom Firearm.

Maximum Stopping Power

At 9th level you gain additional specializations for your firearm. You can switch between these specializations on a short rest. You can also switch between them when you retool between Peacemaker and Boomstick.

You can modify the Peacemaker into:

Big Iron, which scores a critical hit on an attack roll of 19 or 20. Additionally, you can now add double your Intelligence modifier to the damage when you score a critical hit, which is in addition to the normal damage

Slip Gun, which lets you rapid fire up to 6 shots when you take the attack action. Each shot after the second suffers a stacking -3 penalty to the attack roll.

You can modify your Boomstick into:

Punt Gun, which deals bludgeoning damage instead of piercing damage and forces any Medium or smaller creature you hit with an attack to make a Strength saving throw against your spell save DC or be knocked prone. Additionally, once per turn as an action you can expend an upgrade die to reduce your speed to 0 and use Scattershot Blast, which forces every creature in a 30 foot cone to make a Dexterity saving throw against your upgrade save DC, taking bludgeoning damage equal to 1d12 plus your Intelligence modifier if they fail and half as much if they succeed. Medium or smaller creatures who fail the saving throw are also knocked prone. You can expend additional upgrade dice as part of the attack, adding another 1d12 for each die you spend. When you use Scattershot Blast, you must also succeed a Strength saving throw against your spell save DC or be knocked prone.

Sniper, which doubles your weapon's range. As a bonus action, you can reduce your speed to 0 and use No Scope, which lets you add twice the number rolled on any Upgrade dice you spend that round to the attack roll and damage.

Unlimited Dakka

Starting at 15th level, when you roll initiative and have no upgrade dice remaining, you regain 1 upgrade die.

Additionally, you now have 2 extra infusions that can be used on your Custom Firearm instead of 1.