Artificer

Uses technology and inventions as his adventuring power. Ideas for Archetypes are called Crafts; possible Crafts include the Alchemist and the Clockwork Tinkerer.

Class makes inventions which replicate spell effects.

Represents a medieval engineering adventurer.


As a Wizard School

The Artificer represents the technology user of the fantasy world. Often it is portrayed as an alternative casting class. Rather than trying to implement new mechanics, I wanted to offer an alternative that simply reimagines the abilities of existing classes. The problem with this implementation is that the archetype bonuses make it too powerful. The artificer should ultimately have just as wide ranging of spells, but probably fewer of them since its archetype makes up for the benefits gained. Perhaps using the Sorcerer as the base would be better.

Instead of casting spells, you create inventions, contraptions, gizmos, and gadgets.

You are the master of your craft and it is through your craft that you brave the world of adventuring. The artificer is capable of making incredible technological wonders comparable to the magic of wizards.

Instead of spells and cantrips, you create technological devices which do the same thing. Instead of a spellbook, you have a Book of Schematics which you study and use to make your contraptions.

A simple gizmo and gadget would be an alchemical gauntlet which can fire blasts of fire, replicating the Firebolt spell.

An example of this would be a series of wires, tubes, and cloth which replicate the Feather Fall spell.

Instead of an Arcane Tradition, you have a Craft, such as those below.

Craft (Alchemy, Clockwork Tinkerer)
You gain proficiency in a special time on invention, either Alchemy or Clockwork Tinkering. You gain a Craft feature at levels 2, 6, 10, and 14.

Alchemy
Level 2
Bonus Proficiencies
Proficiency with Alchemist’s Supplies

Bombs
As an action, you can create a quick-reacting alchemical bomb from components, found in a spell component pouch or from plants and natural resources from your surroundings and a glass vial, and throw the bomb targeting a corner of a square within range. Only Alchemists can use the materials you have in the same way you can.

Your bombs deal 2d6 + your Intelligence modifier fire damage in a 5-foot radius. Any target in range of the explosion can make a Reflex Save for half damage. If your attack roll is high enough to hit a target standing in the square of the corner you target, they make their Reflex Save at Disadvantage.

Not throwing a bomb on the turn you make it causes it to explode in your hand for 3d6 + your Intelligence modifier fire damage to you and 2d6 damage to everyone within 5ft of you.

You can use an invention slot to increase the damage of a bomb by 1d6 per level of the invention slot.

At levels 5, 11, and 17, this damage increases by 1d6.

Throw Alchemical Device
You can throw an alchemical device, like alchemist’s fire or bomb, with proficiency at a range of 20/60.

Level 6
Expertise (Alchemist’s Supplies)

Potions
You can use an invention slot to create a potion, which can be drank by you or another creature. The invention slot must be high enough to replicate the spell being concocted in the potion. The potion can only affect the creature that imbibes it. A potion made with this ability can replicate the effects of Alter Self, Cure Wounds, Enhance Ability, Enlarge/Reduce, Freedom of Movement, Invisibility, Jump, Lesser Restoration, or Longstrider spells. A potion remains potent for one hour.

Level 10
Intricate Bombs
Beginning at 10th level, you can concoct bombs which deal acid or cold damage in addition to fire.
In addition, you can choose one of the following effects and add it to your bombs. You can do this two times per short rest.
Volatility. Your bombs explode in a 10-foot radius, rather than 5-foot.
Delay. You can set a delay for your bombs, allowing them to explode after a one round delay up to a ten round delay.
Globs. Your bombs cause those who fail their Reflex Saving Throw to burn for one minute after impact, taking an additional 1d6 damage of the type of the exposion per turn until they take an action to remove the globs.
Ingestible. You can ingest your bombs, allowing you to breath the bomb out as a 20-foot cone. Once imbibed, you can hold the liquid in your mouth for up to two rounds. During this time, you cannot speak.

Level 14
Mutagens
Beginning at 14th level, you can concoct a Mutagen by expending an invention slot, a vial, and some reagents.
When the mutagen is imbibed by you, it increases either your Strength, Dexterity, or Constitution by 4, but reduces your Intelligence, Wisdom, or Charisma by 2. Increasing your Strength reduces Intelligence, Dexterity reduces Wisdom, and Constitution reduces Charisma.
The Mutagen lasts for a number of minutes equal to the invention slot level expended. At the end of the duration, you gain one level of Exhaustion. You cannot imbibe another Mutagen until you finish a long rest.

Clockwork Tinkerer
Level 2
Tinker’s Tools and Light Armor Proficiency

Clockwork Arm
The clockwork arm can assist you with all sorts of actions. It can perform basic functions, but not those requiring finesse, like opening a lock.
As a bonus action, it can slam a target, attacking with your Intelligence modifier for 1d6 damage plus your Intelligence modifier.
As an action, your arm can throw an object at a range of 20/60.

Level 6
Expertise (Tinker’s Tools)
Clockwork Bots
You can create bots which replicate the Unseen Servant spell.

Level 10
Gizmo and Gadget Arm
Your Clockwork Arm can activate a gizmo and gadget that you have constructed. The Arm uses your bonus action to activate the gizmo and gadget.

Level 14
Clockwork Golem
You can create a clockwork golem which does your bidding.

@eisdrachen has made an Artificer class, but it is more of a craftsman or infuser of sorts. Giants in the Playground made one and has published it to the DM’s Guild. It is a solid implementation and I would recommend it, though review would be a good thing.

This Unearthed Arcana provides another Artificer.

It touches on the concepts of both types of Artificers I have seen, whether that be the one from the DM’s Guild or @eisdrachen’s.