- "Take these carrier pigeons for example. Each one sent from Machiavelli bears the name of an important Templar in Roma. Eliminate them and you will have more of an impact than a battle ever could."
- ―Pantasilea Baglioni to Ezio Auditore, 1500.[src]
Assassination contracts were assignments given to the Assassins, marking one or more individuals as a threat and ordering their elimination. The details of these contracts were generally sent via carrier pigeon or couriers.
Under the leadership of Rashid ad-Din Sinan, word of the intended target was sent to the Rafiq present within the target's city or region. Novice Assassins were then sent out by the Rafiq to investigate the plans, routines and surroundings of the intended target, amassing information that could be crucial to the actual assasination, which would be carried out by an Assassin of higher rank.
Before said assassination was carried out, the Assassin would be judged on the value of their knowledge and, if deemed sufficient, handed a feather marker which would serve as proof of their success when dipped in the target's blood. Master Assassins, due to their skill, were not obligated to meet with the Rafiq after the investigation had been completed and could immediately proceed with the elimination of the target. Although rare, investigations and assassinations were sometimes carried out by the same person, as was the case with the disgraced Assassin Altaïr Ibn-La'Ahad.
By the 15th century, much of these practices had been abolished, with the Assassin receiving the contract also being the one that carried it out. Following his rescue of Lorenzo de' Medici, Ezio Auditore da Firenze began to serve as the man's unofficial assassin, carrying out contracts in the cities of Florence, Tuscany, Romagna, and Venice. Since these targets were picked out by Lorenzo, they were frequently enemies of the House of Medici; in particular, people that had collaborated with the Pazzi. 
When he was a Master Assassin living in Rome, Ezio's contracts were provided by Niccolò Machiavelli and relayed to him through Pantasilea Baglioni. By eliminating these targets, who were primarily affiliates of the Borgia family, the Brotherhood gradually weakened the position of power held by the Templars.
Ezio could also provide contracts of his own for his Assassin recruits, sending them to countries across Europe and beyond. In completing their missions, the apprentices damaged the Templars' presence in various regions and gained the experience necessary to progress through the Assassin Order.
Having grown somewhat weary by the time he reached Constantinople, Ezio no longer carried out assassination contracts himself, though he still aided the local guild in other ways. As he did in Rome, Ezio recruited citizens and then sent them out on strategic missions across the Mediterranean to train them. This proved critical not only to the apprentices' development but also to the expansion of the Assassins' knowledge and influence in the region.
Age of EmpiresEdit
Upon being introduced to the Assassins in 1716, the pirate Edward Kenway was persuaded by James Kidd to work assassination contracts in the Caribbean for monetary reward. These contracts could be found on a plethora of islands, with the majority being located in the more densely populated cities of Havana, Nassau and Kingston. The people targeted by the Assassins were not limited to Templars however, but also included cruel slave traders, corrupt officials and criminals of all sorts.
In 18th century New Orleans, Aveline de Grandpré would occasionally carry out assassinations on the order of her Mentor, Agaté, who left messages for her in the Saint Peter Cemetery. These missions were meant to sabotage the Templars' attempts to gain power within the region, eliminating new recruits or vital enemy contacts. Similarly, Aveline would receive contracts from Gérald Blanc's informants, targeting various corrupt Templar business rivals active in the city. By eliminating them, more shops became eligible for renovation, allowing slaves to attain employment and a decent wage.
Edward's grandson, Ratonhnhaké:ton, occasionally accepted assassination contracts given to him through couriers, who identified the locations of Templars nearby, allowing him to complete them in his own time. Following his liberation of the Boston and New York districts, Ratonhnhaké:ton also recruited six individuals, who were sent to fulfill contracts around the British American colonies. In this way, his recruits gained experience, acquired valuable resources for the Brotherhood and aided the Continental war effort during the American Revolution.
- In Assassin's Creed II, during memory sequences 13 and 14, as well as the succeeding free-roaming sequence, assassination contracts were still available, even though Lorenzo de' Medici had already died by that point. As it turned out, Ezio was also tasked to assassinate associates of various characters who had been dead for years by then.
- In "Hunting the Hunter," the attacking guards bore Medici colors.
- If Ezio looted the scarecrow target afterward, it yielded a set of keys.
- Contracts were available for Edward to complete as soon as he reached Havana in 1715, despite him not being officially introduced to the system until 1716.