Level 1: Identify, Searing Smite

Level 3: Heat Metal, Magic Weapon

Level 5: Elemental Weapon, Protection from Energy

Level 7: Fabricate, Wall of Fire

Level 9: Animate Objects, Creation

When you choose this domain at 1st level, you gain proficiency with heavy armor and smith’s tools. 

At 1st level, you gain the ability to imbue magic into a weapon or armor. At the end of a long rest, you can touch one nonmagical object that is a suit of armor or a simple or martial weapon. Until the end of your next long rest or until you die, the object becomes a magic item, granting a +1 bonus to AC if it’s armor or a +1 bonus to attack and damage rolls if it’s a weapon.

Starting at 2nd level, you can use your Channel Divinity to create simple items.

You conduct an hour-long ritual that crafts a nonmagical item that must include some metal: a simple or martial weapon, a suit of armor, ten pieces of ammunition, a set of tools, or another metal object (see chapter 5, “Equipment,” in the Player’s Handbook for examples of these items). The creation is completed at the end of the hour, coalescing in an unoccupied space of your choice on a surface within 5 feet of you.

The thing you create can be something that is worth no more than 100 gp. As part of this ritual, you must lay out metal, which can include coins, with a value equal to the creation. The metal irretrievably coalesces and transforms into the creation at the ritual’s end, magically forming even nonmetal parts of the creation.

The ritual can create a duplicate of a nonmagical item that contains metal, such as a key, if you possess the original during the ritual.

Starting at 6th level, your mastery of the forge grants you special abilities:

• You gain resistance to fire damage.

• While wearing heavy armor, you gain a +1 bonus to AC.

At 8th level, you gain the ability to infuse your weapon strikes with the fiery power of the forge. Once on each of your turns when you hit a creature with a weapon attack, you can cause the attack to deal an extra 1d8 fire damage to the target. When you reach 14th level, the extra damage increases to 2d8. 

At 17th level, your blessed affinity with fire and metal becomes more powerful:

• You gain immunity to fire damage.

• While wearing heavy armor, you have resistance to bludgeoning, piercing, and slashing damage from nonmagical attacks.