Blacksmiths were metalworkers who made various objects ranging from weapons of war to simple objects of daily use, such as utensils and locks. During the Renaissance, skilled blacksmiths began to apply their practical craft towards making art, to which architectural ironwork flourished.
Blacksmiths also made a wide variety of weapons and armor, and capitalizing on this opportunity, the Assassins armed themselves by purchasing blacksmiths' wares. The Templars also used the blacksmiths throughout history to arm themselves and their troops, one example being Cesare Borgia employing at least one skilled blacksmith – Auguste Oberlin – to his workforce, who crafted weapons for most of Cesare's army.
Blacksmiths repaired both broken and partially broken armor. Ezio Auditore da Firenze could get all of his equipped armor repaired at once, or as individual pieces. The cost to repair a piece of armor varied with its quality and where on the body it was worn.
During Ezio's travels throughout the various cities of Italy, and during his visit to Constantinople, he bought several pieces of armor, ranging from simple leather armor, to complex, decorated pieces of metal armor.
Under the rule of the Borgia, most merchants had been forced to shut down. As the Assassins under Ezio began to liberate the city, they reopened several shops. In return, the blacksmiths began to sell weapons to the Assassins at a discounted rate, and the blacksmith on Tiber Island sold certain weapons and pieces of armor in exchange for a collection of items.
As well as weapons, Assassins bought ammunition for their ranged weapons from blacksmiths. Ammunition included throwing knives, smoke bombs, and bullets. From the start of the 16th century, once the crossbow was bought, crossbow bolts became available as well.
Blacksmiths seemed to be more brash towards Ezio than the other merchants, blatantly admitting surprise that he was able to afford any of their wares. However, in Assassin's Creed: Brotherhood, this aspect was toned down; they instead made subtly offensive remarks like "One man's coin is as good as another's" when Ezio bought something from them.
When going to a blacksmith in Brotherhood, Ezio had the option to sell trading items for different amounts of money.