Artillerist (5A)

This is an Artificer Specialization for 5A.

An Artillerist specializes in using magic to hurl energy, projectiles, and explosions on a battlefield. This destructive power is valued by armies in the wars on many different worlds. And when war passes, some members of this specialization seek to build a more peaceful world by using their powers to fight the resurgence of strife. The world-hopping gnome artificer Vi has been especially vocal about making things right: "It's about time we fixed things instead of blowing them all to hell."

Greyhawk: Mainly practiced by gnomes and a few humans, many artillerists see their cannon as a toy and only employ it as weapons when they must. A more unusual variant exists among the Flan, where it is not seen as artificing at all, but as totem worship.

Sources: Tasha's Cauldron of Everything/Eberron: Rising from the Last War

Subclass features

Tool Proficiency

When you adopt this specialization at 3rd level, you gain proficiency with woodcarver's tools. If you already have this proficiency, you gain proficiency with one other type of artisan's tools of your choice.

Artillerist Spells

Starting at 3rd level, you always have certain spells prepared after you reach particular levels in this class, as shown in the Artillerist Spells table. These spells count as artificer spells for you, but they don’t count against the number of artificer spells you prepare.

**Artillerist Spells Table**
Artificer Level	Artillerist Spells
3	Shield of Faith, Thunderwave
5	Scorching Ray, Shatter
9	Fireball, Wind Wall
13	Ice Storm, Wall of Fire
17	Cone of Cold, Wall of Force

Eldritch Cannon

Also at 3rd level, you've learned how to create a magical cannon. Using woodcarver's tools or smith's tools, you can take an action to magically create a Small or Tiny eldritch cannon in an unoccupied space on a horizontal surface within 5 feet of you. A Small eldritch cannon occupies its space, and a Tiny one can be held in one hand or worn and counts as an attended object. Once you create a cannon, you can't do so again until you finish a long rest or until you expend a spell slot to create one. You can have only one cannon at a time, and can't create one while your cannon is present.

The cannon is a magical object. Regardless of size, the cannon has an AC of 18 and a number of hit points equal to five times your artificer level. It is immune to poison damage and psychic damage, and the blinded, charmed, deafened, exhaustion, frightened, paralyzed, petrified, and poisoned conditions. If it is forced to make an ability check or a saving throw, treat all its ability scores as 10 (+0). If the Mending spell is cast on it, it regains 2d6 hit points. It disappears if it is reduced to 0 hit points, or after 1 hour. You can dismiss it early as an action.

When you create the cannon, you determine its appearance and whether it has legs. You also decide which type it is, choosing from the options on the Eldritch Cannons table. At 9th level, you can choose two options. At 15th level, your Eldritch Cannon can use all three abilities. The Eldritch Cannon can only use one of these abilities each time you activate it. On each of your turns, you can take a bonus action to cause the cannon to activate if you are within 60 feet of it. A Small cannon can also move on its own with a land and climb speed of 40 ft. whether you activate it or not. As part of the same bonus action, you can direct the cannon to walk or climb up to 15 feet to an unoccupied space, provided it has legs.

Eldritch Cannon Table

Flamethrower: The cannon exhales fire in an adjacent 15-foot cone that you designate. Each creature in that area must make a Dexterity saving throw against your spell save DC, taking 2d8 fire damage on a failed save or half as much damage on a successful one. The fire ignites any flammable objects in the area that aren't being worn or carried.
Force Ballista: Make a ranged spell attack, originating from the cannon, at one creature or object within 120 feet of it. On a hit, the target takes 2d8 force damage, and if the target is a creature, it is pushed up to 5 feet away from the cannon.
Protector: The cannon emits a burst of positive energy that grants itself and each creature of your choice within 10 feet of it a number of temporary hit points equal to 1d8 + your Intelligence modifier (minimum of +1).

Arcane firearm

At 5th level, you know how to turn a wand, staff, or rod into an create an Arcane firearm, a conduit for your destructive spells.

When you finish a long rest, you can use woodcarver's tools to carve special sigils into a ranged weapon, a tiny arcane cannon you made, or a, wand, staff, or rod and thereby turn it into your arcane firearm. The sigils disappear from the object if you later carve them on a different item. The sigils otherwise last indefinitely.

You can use your arcane firearm as a spellcasting focus for your artificer spells. When you cast an artificer spell through the firearm, roll a d8 and gain a bonus to one of the spell's damage rolls equal to the number rolled.

If your arcane firearm is a ranged weapon, you can you can use it as a weapon with your Intelligence modifier (instead of Dexterity modifier) for the attack and damage rolls. The damage of your ranged weapon attacks with your arcane firearm also increases by 1d8.

If your arcane firearm is a tiny arcane cannon you made and you are wielding it as a weapon, you can use an action to activate your arcane cannon. You can use this on the same turn in which you used a bonus action to activate your arcane cannon, thus activating it twice in the same turn. When you create two arcane cannon at level 15, you can wield one in each hand and activate both with one action.

Explosive Cannon

Starting at 9th level, every eldritch cannon you create is more destructive:

The cannon's damage rolls and temporary hit points granted all increase by 1d8.
The range of the canon are doubled. The flamethrower now has a 30 ft. cone. The force ballista has a range of 250 ft, and the protector bot has a radius of a 20 feet.
As an action, you can command the cannon to detonate if you are within 60 feet of it. Doing so destroys the cannon and forces each creature within 20 feet of it to make a Dexterity saving throw against your spell save DC, 3d8 force damage taking the damage of both a flamethrower and ballista attack on a failed save or half as much damage on a successful one. You can throw a Tiny cannon you are holding up to 30 ft as a part of this action.

Fortified Position

By 15th level, you’re a master at forming well-defended emplacements using Eldritch Cannon:

The cannon's damage rolls and temporary hit points granted all increase by 2d8. This replaces the 1d8 gained at level 9.
You and your allies have half cover while within 10 feet of a cannon you create with Eldritch Cannon, as a result of a shimmering field of magical protection that the cannon emits.
You can now have two cannons at the same time. You can create two with the same action, (but not the same spell slot) and you can activate both of them with the same bonus action. You determine whether the cannons are identical to each other or different. You can't create a third cannon while you have two.

Editor's Notes

Polish, polish, polish. The artillerist was in my not so humble opinion a mess.

Defined the difference between Tiny and Small cannon and how it is created.
You can now create as many cannon as you like, but you can only have a limited number active at once.
The cannon now gains multiple options as you advance.
Your arcane firearm can be a missile weapon, in which case you can use that weapon with Intelligence.
At 9th and 15th level damage and (this is new) the temporary hit points granted improve.