Economic system

The economic system referred to the transactions and trade that individuals partook in. To do this, money could be earned to purchase weapons and equipment from merchants by fulfilling missions, pickpocketing, hiring thieves, looting treasure chests, or other more legitimate means.

Known currencies

 * in Renaissance Italy.
 *  in the Ottoman Empire.
 * during the Golden Age of Piracy.
 * in Colonial America. People also paid with Spanish, French, and Portuguese coins,, or colony-specific bills, but it was simplified to just Pounds sterling in the Animus 3.0.
 * in Colonial Louisiana.

15th century
Banks were an essential part of everyday Renaissance life. Ezio Auditore da Firenze came from a family of bankers, and by investing in renovating Monteriggioni, he and his sister Claudia received a share of the profits. Ezio used the money to pay for the following:
 * Services offered by blacksmiths, doctors and tailors
 * Hiring mercenaries, courtesans and thieves
 * Bribing heralds
 * Buying paintings - improving the value of the Villa Auditore - and maps from art merchants to find treasure chests
 * Lessons from mercenaries on how to use long weapons, two-handed weapons and ranged weapons
 * Caravan travel

Thieves would also attempt to rob Ezio; in the event that money had been stolen from him, Ezio could tackle or kill the thief to get it back.

16th century
During the liberation of Rome, Ezio generated income by lending money to reopen shops and faction buildings, repair aqueducts, restore sewer tunnels, and buy shares in landmarks. He could also find exotic items in chests around the city to trade for special upgrades from the stores in Tiber Island, and repurchase the inventions of Altaïr Ibn-La'Ahad's Codex from Leonardo da Vinci. Upon restoring the city of Rome completely, Ezio received the Auditore cape for his efforts.

When Ezio arrived in Constantinople, many shops had been closed after the Byzantines captured the Assassin Dens and the surrounding area. After recapturing a Den, Ezio could reopen the shops, banks and faction buildings, and they would remain open even if the Templars reoccupied a Den. However, should the Templars ever do so, there would be an additional 15% tax cost on all items that could be bought.

Ezio could then use the money earned by his share in Constantinople's shops to renovate other cities reclaimed from the Templars, increasing his daily payment of akçe. He could also increase his revenue by purchasing items from book shops, improving the value of the library in Galata headquarters. During his time in the city, he learned to use bombs and began buying them from black market dealers, and received ingredients from his apprentices in other cities.

18th century
The economy of the American colonies in the 18th century were based around the crafting and trading of goods. Connor and Aveline de Grandpré earned money by arranging the transportation of materials and goods found or bought from those on the Davenport Homestead via land and naval convoys. Profits made through the convoy were determined by where the merchant they traded with, with naval convoys earning more than than those sent to Boston, New York or the Frontier.

Lance O'Donnell could craft a total of three land convoys, with a maximum capacity of eight items to trade per convoy, and three naval convoys with a maximum capacity of fifteen tradeable items. Liberating forts and undertaking privateer contracts in the Aquila made the trade routes safer, lowering the risk percentage as well as lowering taxes. For example, the risk of a naval convoy being attacked dropped from 80% to 5% after the Aquila cleared the route. In the event of the convoy being attacked while on the road, Connor would be notified that it was in danger, and had to defend it himself or send his recruits to do so, otherwise the profits would be lost. There was nothing that could be done if a naval convoy was lost at sea however.

Unlike Renaissance Italy, general stores provided all the items Connor needed. He could make money by selling them his hunting spoils, the value and quantity of which depended on how the animal was killed, with those slain by a single strike of an arrow or the Hidden Blade earning him more than those that were slashed or shot by a weapon multiple times, as firearms, trip mines, and rope darts all ruined the pelt. The Aquila could also be upgraded with purchases made from the harbormasters.

Trivia

 * Ezio and Connor could throw money to attract a crowd of greedy civilians, distracting both guards and their targets alike, or to dismiss irritating minstrels or orphans.
 * In Assassin's Creed: Bloodlines, upgrades to Altaïr Ibn-La'Ahad could be purchased by finding Templar coins.