War machine
- "War machines. I have constructed weapons for all the Borgia guards and other terrible monstrosities besides."
- ―Leonardo about his machines.[src]
The War Machines were four mechanical devices designed by Leonardo da Vinci for the Borgia forces during the early 16th century.
They each feature in one of four exotic missions for Assassin's Creed: Brotherhood, and can be found in cities or towns outside Rome. In order to destroy them, Ezio commandeered and destroyed all four of these machines, severely reducing the Borgia's military strength. To ensure that they would not be rebuilt, each machines' blueprint was burned before commandeering it.
The War Machines
Chariot machine gun
Like the name says, its a chariot with a fast-firing cannon that can be used to take out dozens of enemies easily, while riding or not. Because of the fast moving and fast firing, the chariot machine gun is great for chases or surprise attacks.
In order to destroy the machine, Ezio traveled to Colli Albani. After finding and burning the machine plans, Ezio managed to blow the machine gun, however, a second one appeared, and Ezio chased it by with a horse. When Ezio took control of the weapons several mounted arquebusiers and Archers at rooftops tried to stop him, but Ezio managed to escape and destroyed the weapon once and for all.
The Bomber

A advanced version of the flying machine, refereed as "Flying Machine 2.0" by the memory's name. This version of the flying machine works just like the first one, using fire to keep itself on the air, but equipped with a cannon mounted on top. In order to keep it on air, Ezio must shoot the ground to make fire.
To destroy the Bomber, Ezio went to Valnerina and interrogated the weapons engineer. With the plans location, Ezio avoided the guards and burned the plans, then he found the tower where the machine was kept. After a lot of climbing, Ezio finally reach the top of the tower and the bomber. With the weapon, Ezio destroy several factories and some chariots with materials as well, before finally crashing into a tower, destroying the bomber.

The naval cannon is modified gondola carrying a gun that shoots fireballs. The speed and small size of the weapon make it a hard target for the enemies, while the powerful cannon can destroy even the biggest ships. The weapon needs two people to work, however, Ezio manages to use it alone.
At the docks of Naples, Ezio find the engineer of the weapon. The engineer choose to aid Ezio, showing him the way to the place where the weapon is kept. When Ezio found the weapon he killed all the guards guarding it, and managed to flood the place to steal the weapon. Once in the sea, Ezio used the weapon to destroy four Templar ships. Once all of them are destroyed, Ezio uses the boat's cannon on the boat itself destroying it.
The Tank

The most powerful weapon made by Leonardo, the tank is a mobile cannon platform with wooden armor, that can shot in several directions. Thanks to the strong armor, the tank can't be damaged by bullets and can resist to several cannon balls before being destroyed. But this power comes with a price, a crew of at least three people is needed to use the weapon.
When Ezio arrives at Monte Circeo, he finds the engineer of the weapon and it's bodyguard. Ezio follows them to a heavily guarded factory, where he interrogates the engineer, who tells him the location of the machine plans, the machine itself and also a group of mercenaries that could help him. Once the plans are burned and the mercenaries free, Ezio and his "crew" venture in a series of caverns. At the end of the cavern, he finds the tank and use it to battle his way to the factory. Once all other tanks are destroyed, Ezio uses a mounted cannon to finally destroy his tank.
Trivia
- Every one of Leonardo's machines in the game has infinite ammunition.
- When Ezio first arrives in Rome, a herald can be heard announcing the exhibition of the "war machines of Maestro da Vinci" to the crowd.
- In the Assassin's Creed: Brotherhood novel, there are no fully functioning war machines. Leonardo tells Ezio that he created the design so it wouldn't work, but in a discreet way.
- In the tank memory, Ezio destroys his own tank with only one cannon ball, even if takes several shots to destroy it during the battle.
- A miniature replica of each one of the machines are found at the hideout after completing their memories.