Runesmith

When you choose this subclass at 3rd level, you learn a language of your choice among Giant, Draconic or Sylvan. This becomes your Runic Script. Your Runic Script has a School of magic associated with it: Abjuration for Giant. Evocation for Draconic and Conjuration for Sylvan. Whenever you cast a spell of the school associated with your runic script, you gain a +1 bonus to your spellcasting ability.

In addition, you gain proficiency with the Battleaxe, Greataxe, Longsword and Greatsword.

Runesmith Spells

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

Runesmith Spells
Artificer Level	Runesmith Spells
3rd	Ice Knife, Protection from Evil and Good
5th	Aganazzar's Scorcher, Warding Bond
9th	Crusader's Mantle, Thunder Step
13th	Fire Shield, Death Ward
17th	Steel Wind Strike, Dispel Evil and Good

Runecrafting

At 3rd level, you can use your smithing tools to inscribe spells in the form of runes into your armor, weapons and shield. At the end of a long rest, choose a number of artificer spells you know equal to your proficiency bonus, they must be of the transmutation school or the school associated with your runic script. Each of the spells becomes a rune inscribed into a piece or armor, a shield or a weapon you are proficient with. The item must be made of metal. 

While you are holding the weapon or shield, or wearing the piece of armor, you can cast the inscribed spell without spell components. The rune then fades from the item. At the end of a long rest any remaining runes fade.

Extra Attack

Beginning at 5th level, you can attack twice, instead of once, whenever you take the Attack action on your turn.

Runic Warrior

Starting at 9th level, whenever you take the attack action on your turn, you can forgo one of your attacks and cast a spell inscribed as a rune. The spell has to have a casting time of one action.

in addition, whenever you finish a short rest, you can reinscribe one of your expended runes. 

Runic Secrets

At 15th level, you encovered an acient secret rune. You learn one spell of any class of a school associated with your runic script. A spell you choose must be of a level you can cast, as shown in the artificer table, or a cantrip. The chosen spell counts as an artificer spell for you and does not count against the number of spells known.