The tabletop campaign story settings of Dungeons & Dragons are full of magical swords and enchanted suits of armor, which raises two questions: who forges these panoplies of battle and why can't players also try their hands at crafting them? With a vivid imagination and an open-minded Dungeon Master, it's more than possible for a D&D player to create a heroic adventurer character who also happens to be a talented blacksmith, creating excellent weapons, armor, and tools both magical and mundane.
There are two important historical details players should keep in mind when creating a blacksmith character for their medieval and non-medieval D&D campaigns. First, real pre-modern blacksmithing was rarely a one-person job. Contrary to the image of an apron-clad Blacksmith working alone in their forge, historical smithing was a team effort, with the various members of blacksmith guilds working together to stoke the forge, heat the iron, then take turns hammering the metal into shape. Second, blacksmiths in cultures all across the world were frequently thought to have supernatural powers, thanks to their secret knowledge of how to mold metal and tame the fiercest fires. From this perspective, the archetype of a blacksmith meshes perfectly with the magical heroes so common to Dungeons & Dragons.
Theoretically, any Dungeons & Dragons character class can be a Blacksmith as long as they have a decent Strength score and proficiency in Smith's Tools. Dwarf characters automatically gain proficiency with Smith, Brewer, or Mason tools, while non-Dwarf characters can gain proficiency with any artisanal tool of their choice if they choose the Guild Artisan background (as mentioned earlier, membership in a blacksmithing or armorer guild is true to the real-life history of pre-modern smithing). The following 5th Edition classes and sub-classes, however, mesh particularly well with the "blacksmith takes up a life of adventure" concept.
D&D Blacksmith Subclass Candidate #1: Forge Domain Cleric
The Cleric, one of the four core classes of D&D, is a battle-ready priest who casts divine magic empowered through the bond of devotion they have with their patron deity. A "Forge Domain" Cleric honors and reveres a god of fire, crafting, or blacksmithing, such as the Greek god Hephaestus, gaining thematically appropriate spells such as Branding Smite or Heat Metal to supplement the usual D&D cleric spells of healing, protection, and holy damage. In addition to these spells and a resistance to fire, a Forge Domain Cleric has access to divine abilities which let them enchant weapons and armor or transform piles of random metal into any weapon, armor set, or object worth 100 gold pieces or less.
D&D Blacksmith Subclass Candidate #2: Battlesmith & Armorer Artificers
The D&D 5th edition Artificer class, first revealed in the Eberron: After The Last War setting book and expanded on in Tasha's Cauldron of Everything, is the go-to class for player who want their blacksmith characters to create magic weapons, clockwork automatons, or other achievements of magical technology. Every Artificer can infuse items with magical properties and create spell-casting relics, but two Artificer Subclasses fit the "magical blacksmith" archetype like a glove.
Besides having the word "smith" in its name, the "Battlesmith" Artificer also offers a list of close-rang spells which favor the creation of tough yet magical hammer-wielding frontline characters. Additionally, each Battlesmith has their own custom-made "Steel Defender," a mechanical companion which supports them in battle.
The "Armorer" Artificer, in contrast, is for D&D players who are fans of the Iron Man movie trilogy and want to build a magically-augmented suit of armor "in a cave, with a box of scraps." An Armorer Artificer can take any set of protective equipment and make it into a suit of "Arcane Armor," crackling with lightning and various kinds of defensive magics.
D&D Blacksmith Subclass Candidate #3: Battle Master & Gunslinger Fighters
Some D&D players may not want to be a blacksmith who invokes the powers of gods or infuses their creations with powerful enchantments. For those who want their Blacksmith PCs to be paragons of natural skill and crafters of plain, well-forged steel, two D&D Fighter subclasses may be just what they're looking for.
The "Battle Master" Fighter of D&D 5th Edition is a master of weapon techniques and tactics, using special abilities called "Maneuvers" to control the flow of battle and defeat their opponents with skill. One of their 3rd level abilities, "Student of War," also lets them gain proficiency with smith tools if their race or background didn't already grant it. A "blacksmith" Battle Master player character is a warrior who knows everything there is to know about weapons and armor: how to kill with them, repair them, or forge them anew.
The "Gunslinger" Fighter subclass, introduced by Matthew Mercer in his long-running Critical Role Dungeons & Dragons campaign, is for players who want their characters to be the designers and wielders of early firearms such as matchlock rifles, wheel-lock pistols, or pepperbox-style revolvers. Besides being able to pull off flashy "trick shots" and other feats of marksmanship, Gunslinger Fighters also have a set of abilities which let them design their own custom, yet temperamental firearms and repair them whenever they break.