Bomb

Bombs were explosive weapons available since the Middle Ages, and could be used for a variety of tactics, including escape, assault and distraction.

Smoke bombs
Smoke bombs were devices that were used more for distraction, rather than attack. Using a powder technology from the Far East, the bomb released a thick, grayish smoke screen for about eight seconds when thrown.

With one, an Assassin was able to halt any enemy or target, and allow for an easy assassination or escape. This allowed them to strike specific targets, or take down larger groups of enemies without being seen or encountering resistance.

History
Altaïr Ibn-La'Ahad had access to smoke bombs during his quest for the Chalice. He could carry up to five of them at a time, though evidently stopped using them after the events at Solomon's Temple.

Smoke bombs were the only type of bombs that were commonly available to Ezio Auditore da Firenze up until the 16th century. However, upon traveling to Constantinople during his search for the Seals, he gained access to a far more extensive choice of bombs.

In the Renaissance, smoke bombs were disposable, and had to be purchased for 350 florins each. Ezio could carry a maximum of three at once, which he stored in a non-upgradeable pouch.

Ezio also made use of smoke bombs in Rome, though the actual cloud itself was visually a lot smaller than during the previous century. Smoke bombs were also used by Assassin recruits to stun guards once they reached the rank of Veterano (Veteran).

Hand-held bombs
"Quite little bombs, but effective enough to, say, wreck ships or disperse a camp."

- Leonardo da Vinci.

Hand-held bombs were small explosive devices designed and manufactured by Leonardo da Vinci. Consisting of a small, steel ball filled with sulfur, charcoal and potassium nitrate, they also possessed a small fuse which required lighting before the device could be detonated.

History
The bombs were first used against Cesare Borgia's diehards, who had amassed a sizable military force in the city of Valencia.

During the attack on Valencia, Ezio and Niccolò Machiavelli, each equipped with ten hand-held bombs, brought chaos to Cesare's military forces. They destroyed twelve Borgia ships, and an entire military encampment.

Crafting
Upon traveling to Constantinople, Ezio learned how to create a wide range of bombs, with up to 300 variations. In general, they are divided into three categories: lethal, tactical and diversion.

The Assassins have set up Bombs Crafting Stations troughout the cities to be able to craft bombs where ever a station is.

The bombs could be customized based on their different components; casing, gunpowder layer, and effect layer. The gunpowder layer defined the properties of the explosion itself, and the effect layer a further result after it; such as the scattering of caltrops.

Ezio could collect different resources for each of these, and could craft up to five bombs per pouch, given a single combination.

Tripwire
Tripwire bombs take a moment to be set, but once armed, they explode when stepped on. One bomb is able to kill multiple opponents upon being detonated.

Splinter
Splinter bombs killed or injured targets upon impact, and could disperse enemies with its deadly shrapnel.

Caltrop
Caltrop bombs impeded enemy movement by dispersing small spikes across the ground, rendering its victims vulnerable in combat. They could also be used for halting or slowing enemies during a chase.

Lamb Blood

Lamb blood bombs scare enemies by causing a mist of blood to rise after detination.

Assassin's Creed II

 * The smoke bomb pouch is labelled as "small" despite not having any upgrades.
 * In the memory "Cheaters Never Prosper," the three guards and Dante Moro are immune to smoke bombs.
 * While looting Brutes, there is a high chance of obtaining smoke bombs.
 * Smoke bombs are very helpful for earning the achievements "No Hitter", "Messer Sandman," and "Sweeper."

Assassin's Creed: Brotherhood

 * The smoke bomb appears as a multiplayer ability.
 * There seems to be a small spark of light when a smoke bomb is deployed, unlike in Assassin's Creed II, where there is no spark.
 * One BAM (Brotherhood Assist Move) has the Assassins throw numerous smoke bombs around Ezio before descending to aid him.
 * The player may lock onto a far-off NPC before pressing the "throw bomb" button to throw the smoke bomb from a distance.
 * Papal guards are immune to the effects of smoke bombs if not taken by surprise, i.e. in combat.
 * Cesare Borgia and pickpockets are completely immune to Smoke Bombs.

Assassin's Creed: Revelations

 * Both Smoke bombs and Tripwire bombs exist as Multiplayer abilities in Assassin's Creed: Revelations.
 * It is confirmed that enemies in Assassin's Creed: Revelations have the ability to use smoke bombs.