Firearm

Firearms are a class of long-ranged weapons that launch projectiles at a high velocity through the confined burning of propellants. They were used as early as the late Middle Ages.

High Middle Ages
"The knowledge of projectile combat is not new to us, having been observed amongst our Eastern neighbors. But their weapons were much larger – and insufficient for our needs."

- Altaïr Ibn-La'Ahad's Codex, page 28.

Though he knew of firearms that were being used in ancient China, the Assassin Altaïr Ibn-La'Ahad took little interest in them; realizing that the weapons were of no use to his Order in their current size.

As such, upon obtaining the Apple of Eden, he successfully used the knowledge it held to miniaturize the design, "embedding their fiery weapon into a form that can be worn on the wrist."

Along with the formulation of a combustible powder that could be made from common ingredients, Altaïr kept the schematics for the Hidden Gun a secret, available to only the Brotherhood's most trusted allies. Sometime afterwards, he recorded all details of these in his personal journal.

Renaissance
In Italy during the Renaissance, another Assassin, Ezio Auditore da Firenze, came into possession of Altaïr's Codex, and showed the pages to Leonardo da Vinci. Leonardo deciphered the instructions, and was able to construct the Hidden Gun for Ezio's use.

Though firearms were uncommon until the early 16th century, after Cesare Borgia forcibly recruited Leonardo into his employ around 1499, the engineer was made to design a wheel-lock firearm for use by the Borgia armies.

Cesare's ally, the French baron Octavian de Valois, received a personalized, golden wheel-lock firearm from Leonardo, and kept it with him at all times. During the Fall of Monteriggioni, Cesare used this pistol to kill Mario Auditore.

A variety of firearms began to circulate among common guards as well, with arquebusiers wielding long muskets or arquebuses, and with several horsemen and Papal Guards using shorter pistols.

During Ezio's travels to Constantinople, he encountered Turkish soldiers using Ottoman flintlock muskets, as well as Janissaries who used short pistols. The Assassins of the local guild also made use of firearms to guard nearby dens, ranging from simple muskets to cannons.

Meanwhile, the Byzantines forces had designed an early version of a flamethrower, which they used to deliver Greek Fire. They also had a form of a machine gun, which was similar in construct to Leonardo da Vinci's prototype. Both of these were then later adapted by the Assassins, in order to aid them in defending their dens.

Colonial America
By the Golden Age of Piracy, muskets with bayonets had become standard equipment for armies and navies, while high-ranking soldiers like officers and Jägers wielded flintlock pistols.

As it still took time to reload and clean firearms, pirates were usually accustomed to carrying multiple pistols at any one time. As such, the pirate and Assassin, Edward Kenway, wielded four flintlock pistols in combat.

By the 1760s, the French-African Assassin Aveline de Grandpré was able to wield muskets, as well as two Queen Anne pistols. Similar to the flintlock pistols, these were single shot weapons and took time to reload. The Colonial Assassin Connor was able to wield a musket as well as two flintlock pistols. By the American Revolutionary War, some pistols were advanced enough to carry two shots at a time.

Russian Revolution
During the late 19th and early 20th century, in the Russian Revolution, the Russian Assassin Nikolai Orelov wielded a modern bolt-action, alongside the usual weaponry of his time.

Modern times
In 2012, Assassins continued to wield firearms in combat, and once used them on a direct assault on Abstergo Industries, in an attempt to rescue Desmond Miles.

Though Desmond overheard the exchanged gunshots through the facility's intercom, Dr. Warren Vidic eventually told him that the rescue attempt had failed, and that most of the team had been killed. Firearms were, at this point, standard equipment for Abstergo guards in the Rome facility.

Daniel Cross threatened Desmond with a pistol when he found the first power source. When Desmond searched for the second source, Cross, as well as Abstergo guards shot at him. Over an intercom, Warren Vidic authorized guards to use deadly force when Desmond assassinated Cross at the Abstergo facility.

When rescuing his father from Vidic, Desmond took Cross' pistol and could use it in the latter half of his assault. The pistol, a, worked similarly to Connor's flintlocks, only that it had a much larger magazine, a higher rate of fire, and had a suppressor attached.

Trivia

 * A number of firearms were available in Assassin's Creed: Project Legacy, including the, , and.
 * Owning two M1917 revolvers in Project Legacy granted the "Akimbo" achievement.
 * In Assassin's Creed III, the Pirate Flintlock was awarded upon the completion of the memory "Sinking a Secret".