Economic system

The economic system referred to an interaction feature that was first introduced in the Animus 2.0, based on the transactions and trade that an ancestor partook in.

Currency
As the heart of economic system, money has played a part in the everyday operations of the Assassins since the Renaissance. Measured in  in Italy,  in the Ottoman Empire, and  during the American Revolution, money could be obtained during the course of Ezio Auditore da Firenze and Connor Kenway's memories, by progressing through the tasks set before them, or by a variety of other means, such as assassination contracts and crafting.

Notably, thieves could steal from an Assassin without them noticing. In the event that money had been stolen from him, Ezio could tackle or kill the thief in order to get it back, as well as using a throwing knife on them to retrieve it.

Earning money
Ezio Auditore also had a number of options for earning money, some respectable, some less so.

Looting and robbing
Ezio could obtain money, and sometimes other useful items, by looting treasure chests and dead bodies.

Pickpocketing civilians was another way for him to acquire a few coins at a time. Significantly more could be gained by tackling other pickpockets or Borgia messengers. After completing a number of guild challenges set by the thieves in Rome and Constantinople, a hired group would automatically begin pickpocketing money for Ezio.

Upgrading Monteriggioni
The city of Monteriggioni was introduced to Ezio in a state of disrepair, with many buildings in poor condition or closed completely; leaving him with the task of restoring it to its former glory. Though the Villa Auditore was not directly upgraded, it was cleaned and improved along with the rest of Monteriggioni as Ezio spent money on renovations and upgrades for it.

Any money invested in Monteriggioni would increase its value, and the city would gain a higher income from rent and taxes as Ezio upgraded it, with the profit being retrievable from a chest behind the desk at which Claudia Auditore da Firenze worked. Also, as the landlord of Monteriggioni, Ezio was entitled to discounts at the stores in the city, of which the percentage elevated as they were repaired.

Upgrading Rome
When Ezio arrived in Rome, he found the city in a state of disrepair, on a much wider scale than that of Monteriggioni, after an extended period of Borgia rule. Vowing to help return the city to its previous splendour, Ezio firstly destroyed the Borgia towers around Rome, which allowed him to buy shops and faction buildings, repair aqueducts, restore sewer tunnels, and buy shares in landmarks.

Income was then gained from rent generated by the restored city buildings, and would be deposited in banks for Ezio to collect periodically. Upon restoring the city of Rome completely, Ezio received the Auditore cape for his efforts.

Trading
In Ezio's time in Rome, money was not the only treasure to be found in chests or the pockets of his deceased enemies. Gems, spices and other exotic items could be looted and sold at shops for additional income.

After collecting specific items for shop owners in the Tiber Island area of Rome, Ezio gained access to various upgrades and items that he could utilise.

Upgrading Constantinople
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 addition 15% tax cost on all shop 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 and bomb ingredients.

Spending money
There were also a number of ways to spend money in the series.

Hiring factions
Ezio could hire thieves, courtesans and mercenaries throughout Italy to distract or kill enemies.

In Constantinople however, courtesans were not accepted in Ottoman society, so the Romani took their place for Ezio to depend upon.

Blacksmiths
Ezio could buy armor – or have it repaired – and weapons at blacksmiths. Upgrading his armor and weapons provided Ezio with better resistance to attacks, or larger damage bonuses in combat.

With this in mind, most armor and weapons needed to be bought, though exceptions included the armors of Altaïr, Brutus, and Ishak Pasha, along with the Master Assassin Armor.

When it came to weapons, the Hidden Blades could only be upgraded by visiting Leonardo da Vinci, and faction challenge weapons had to have their prerequisites met before they were awarded to the Assassin. Ezio also had two swords that cost him nothing, which were the common sword and the Assassin Yataghan sword.

Aside from purchasing armor and weapons, blacksmiths also sold ammunition like throwing knives, bullets for the Hidden Gun, and crossbow bolts. Also, once Ezio acquired a pouch to store them in, blacksmiths also sold smoke bombs for him to refill it with.

Doctors
Doctors sold both medicine and poison, as well as offering instant healing services.

Once provided with the necessary trade items in Rome, doctors offered a more potent poison for Ezio to use, which sent his victims into a state of instant delirium.

Tailors
Buying additional pouches at tailor shops allowed Ezio to carry more equipment – including more medicine, smoke bombs etc.

On visiting a tailor, Ezio could also get his robes dyed in new colors to change his appearance.

Also, after Ezio had destroyed all of Leonardo's war machines, the inventor offered him the use of the parachutes that he had had created, and told him that he could go to a tailor whenever he needed to buy more.

Art merchants
Art merchants sold treasure maps – useful investments in the search for more money – as well as artwork to enhance the value of Ezio's hideout in either Monteriggioni or Rome's Tiber Island.

Book shops
In Constantinople and Cappadocia, Ezio could buy books and treasure maps from book shops, which replaced art merchants in the Ottoman Empire.

By doing this, he expanded the library back at the Assassin headquarters in Galata, also increasing the amount of akçe that he received periodically.

Bombs
Ezio could also buy ingredients for bombs from doctors, blacksmiths, black market dealers and from Piri Reis's shop in the Grand Bazaar, which allowed him to stockpile ingredients to use at bomb-crafting stations.

Heralds
To decrease notoriety in Italian cities, or Templar awareness in Constantinople, Ezio could bribe heralds so that they spoke of different news, concealing the actions of the Assassins from the general public; this bribe consisted of 500 florins or 100 akçe.

Combat skills
In order for Ezio to receive training for long weapons, two-handed weapons and ranged weapons, he needed pay the trainers at the Villa Auditore in Monteriggioni for the cost of their tutelage.

Generosity
By throwing away a handful of coins, Ezio could attract a crowd of greedy civilians, distracting both guards and his targets alike.

Hunting
The Assassin Connor Kenway could sell pelts and other resources collected from hunting animals, such as bears or elk. The value and quantity given for them 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 an example.

Property
Though not much is currently known about it, there was a property system that Connor could make use of.

Source

 * Assassin's Creed II
 * Assassin's Creed: Brotherhood
 * Assassin's Creed: Revelations
 * Assassin's Creed III