Railgunner

A Railgunner fights with a potent and lethal hand-crafted Railgun, making use of rounds that can devastate single targets. While many compare their destructive abilities to those of an Artillerist, Railgunners prefer the precision and silence before unleashing a deadly, single shot.

Original subclass made by Rain-Junkie.

Level 3: Tools of the Trade

You gain the following benefits.

Ranged Weaponry. You gain proficiency with Martial Ranged weapons.

Tool Proficiency. You gain proficiency with Smith’s Tools. If you already have this tool proficiency, you gain proficiency with one other type of Artisan’s Tools of your choice.

Ballistic Crafting. When you craft nonmagical or magic Ammunition, the amount of time required to craft it is halved.

Tool Proficiency

You gain proficiency with Smith’s Tools. If you already have this tool proficiency, you gain proficiency with one other type of Artisan’s Tools of your choice.

Level 3: Railgunner Spells

When you reach an Artificer level specified in the Railgunner Spells table, you thereafter always have the listed spells prepared. Additionally, you ignore the Melee Weapon requirement for the spells gained from this feature if you use your railgun.
Unfortunately, due to corporate greed, most of these spells (Hail of Thorns, Zephyr Strike, Conjure Barrage, Staggering Smite, Banishing Smite, & Conjure Volley) need to be added manually.

Railgunner Spells

Artificer Level	Prepared Spells
3	Hail of Thorns, Zephyr Strike
5	Locate Object, Shining Smite
9	Nondetection, Conjure Barrage
13	Freedom of Movement, Staggering Smite
17	Banishing Smite, Conjure Volley

Level 3: Lorentz Railgun

Your experiments have resulted in a deadly firearm, a Lorentz Railgun. It counts as a Martial Ranged weapon, but only you're proficient with it. It deals 1d12 Piercing damage on a hit, and it has the Ammunition, Range (150/600), Heavy, and Two-Handed properties. You can only make an attack with your Lorentz Railgun once per turn, as it vents the heat from its last shot.

In addition, you also create an ammunition pouch for your Lorentz Railgun. As a Bonus Action you can conjure 10 nonmagical firearm bullets, which appear inside the pouch. These bullets last until you use this feature again.

Your Lorentz Railgun's damage die increases when you reach certain levels in this class, at 5th level (2d12), 9th level (3d12), 13th level (4d12), and 17th level (5d12).

At the end of a Long Rest while you have your Smith's Tools with you, you can create a new Lorentz Railgun with 50gp worth of supplies, ammunition pouch, or both. If you already have a Lorentz Railgun, the original breaks and stops functioning.

Adaptive Protocol

Starting at 3rd level, your tinkering has allowed you to adapt your Railgun with a variety of firing modes, called Protocols. You gain two Protocol options of your choice. You gain another one at 5th, 9th, and 15th level. When you finish a Long Rest, you can also replace one Protocol you have with a different one.

As a Bonus Action, you can activate one of your Protocols. Each Protocol grants you a benefit while it's active, and a Protocol lasts for 1 minute or until you activate a different Protocol. Once you activate an Adaptive Protocol, you can’t activate that same Protocol again until you finish a Short or Long Rest or until you expend a spell slot of 1st level or higher.

Acidblast RGP-0751

Turning your shots into a highly corrosive payload, the Acidblast RGP-0751 eats away at anything you target with it. You can have attacks with your Railgun deal Acid damage, rather than piercing damage. When you damage a creature with an attack from your Railgun, that creature takes an additional 3d4 Acid damage at the start of their next turn.

Cyroclasm RGP-0273

Intended to disrupt faster foes, the Cyroclasm RGP-0273 provides the assurance that your foes won't be reaching you. You can have attacks with your Railgun deal Cold damage, rather than Piercing damage. When you damage a creature with an attack from your Railgun, its Speed is halved until the start of your next turn.

Flashfire RGP-0079

Designed to blast through tight ranks, the Flashfire RGP-0079 makes quick work of many foes. You can have attacks with your railgun deal Fire damage, rather than Piercing damage. When you damage a creature with an attack from your railgun, other creatures within 5 feet of your target take Fire damage equal to your proficiency bonus.

Longshot RGP-3540

Calibrated for longer range engagements, the Longshot RGP-3540 ensures every bullet counts. You can have attacks with your Railgun deal Force damage, rather than Piercing damage. Attacks with your Railgun while this Protocol is active score a Critical Hit on a roll of 19 or 20, and attacking with your Railgun at long range doesn't impose Disadvantage on your attack rolls.

Sparkstriker RGP-1774

Made to increase your gun’s energy output, the Sparkstriker RGP-1774 sends a massive surge of electricity into your target’s body. You can have attacks with your Railgun deal Lightning damage, rather than Piercing damage. When you damage a creature with an attack from your Railgun, the first time that creature willingly moves 5 feet or more before the start of your next turn, it takes 3d6 Lightning damage.

Thundermonger RGP-0165

Tuned to give your shots as much force as possible, the Thundermonger RGP-0165 punches holes through enemy ranks. You can have attacks with your Railgun deal Thunder damage, rather than Piercing damage. When you damage a creature with an attack from your Railgun, you can push it up to 10 feet directly away from you.

Venomdrive RGP-5735

With the purpose of debilitating the enemy, the Venomdrive RGP-5735 blasts your target with a powerful toxin. You can have attacks with your Railgun deal Poison damage, rather than Piercing damage. When you damage a creature with an attack from your Railgun, that creature has Disadvantage on the next attack roll it makes.

Wallbreaker RGP-3578

Designed for if your target is behind cover, the Wallbreaker RGP-3578 punches through even the toughest of terrain. You can have attacks with your Railgun deal Bludgeoning damage, rather than Piercing damage. Whenever your Railgun hits an object, the hit is a Critical Hit, and nonmagical Total Cover is treated as Three-Quarters Cover.

Level 5: Magnetic Acceleration

At 5th level, when you roll a 1 or 2 on a damage die for an attack you make with your Railgun, you can reroll the die and must use the new roll, even if the new roll is a 1 or a 2. Additionally, while you have a Protocol active, you can add your Intelligence modifier to the damage of your Railgun.

Railgun Upgrade. You gain a +1 bonus to attack and damage rolls made with your Railgun. This bonus increases to +2 at level 9. (The bonus to attack rolls must be added manually.)

Exhaust Vents

Starting at 9th level, improvements to your Railgun allow you to siphon any excess heat for more practical uses. When you make an attack with your Railgun, you can choose one of the following options:

• The force of the shot pushes you up to 20 feet in a direction of your choice. This movement doesn't provoke Opportunity Attacks.
• A 5-foot radius Sphere centered on you becomes Lightly Obscured until the start of your next turn. Creatures inside this Sphere gain Half Cover from attacks originating outside the Sphere.

You can use this feature a number of times equal to your Intelligence modifier (minimum of 1), and regain all uses when you finish a Long Rest. Additionally while a Protocol is active, attacks you make with your Railgun deal an additional 1d12 damage.

Level 15: Overclock

By 15th level, you have became adept in pushing your Railgun to its limits. When you activate a Protocol, you can activate an additional Protocol without expending an additional spell slot. You gain the benefits of both Protocols. Additionally, when you miss an attack roll with your Railgun while a Protocol is active, you can expend one use of your Flash of Genius feature to grant a bonus to the attack roll equal to your Intelligence modifier (Minimum of 1), potentially causing the attack to hit.