The health system has been adjusted to allow for a more dynamic and participatory experience, meaning that the "memory sync" system used in the first game only helps to recharge health up to a certain point. More grievous injuries will require a trip to one of the many street-side doctors, who can help return Ezio to full strength.
As well as using water as a hiding place, the player can utilize a broader array of scenery as cover and can now blend in with any crowd rather than a group of scholars dressed in white, as in Assassin's Creed. Like in the 2006 video game Hitman: Blood Money, there will be a notoriety system, and the player will become more notorious as Ezio completes more missions, however Ezio's infamy can be reduced by bribing, removing wanted posters of him or assassinating witnesses. Also, a day and night cycle has been added to the game, giving the sense of a passage of time but additionally certain missions will only be able to be performed during the day or night. The game will also feature some sort of economic system that makes it possible to hire services from non-player characters, or "factions": Thieves, Prostitutes, and Mercenaries. Each faction has their own advantages. Thieves will help the player fight enemies and do certain activities like distracting guards, stealing money, and setting up fires for the use with the glider. Mercenaries will help in fighting and can also fight some people without involving the player himself in the fighting. Prostitutes act similarly to the monks in Assassin's Creed in that they can cover the player's presence from the guards. Additionally, they can distract guards. The player can find faction members inside cities or by going to the leader of a faction. Hiring them costs the player money, and if the faction members were recruited with help of a faction leader, the leader will require a favor from the player in order for the player to get any associated reward.
The trailer, which debuted at E3 2009, displayed many new things such as improved parkour mechanics. The main reveal of the trailer involved Ezio withdrawing his hidden blade to access a rudimentary gunpowder-based mechanic on his wristblade to take out a target from a distance. It has also been confirmed at E3 2009 that Desmond himself will "do more than just walk" in this game. Another feature, as seen in the gameplay video, no cover is safe, as guards can search them. To counter this Ezio has the ability to assassinate the incoming guards before detection, and placing the bodies in his former hiding location (he drags them into haystacks, places dead enemies on the bench he was sitting at between two allies etc.
Besides the main city of the game, the player can access hidden locations such as catacombs and caves, the contents of which have been compared by the developers to the Prince of Persia series. Exploring these locations rewards the player. It has also been said that the player can choose to throw money to the ground, which attracts the attention of nearby civilians, creating a distraction, and throw smokebombs in order to elude guards that are chasing him. Additionally, the eagle vision from the first game has been improved, now giving the option of remaining in third person with eagle vision initiated, allowing the player to spot targets while moving.
Ezio can use various types of weapons, like swords, daggers, halberds, axes and spears. The player can buy his own weapons from shops all over town, from blades to bullets. Ezio, unlike his ancestor Altaïr , the protagonist from Assassins Creed, can disarm his opponents with various attacks and counter-attacks. He learns his fighting skills from his uncle, Mario Auditore. The combat skills include boxing, Sang-raa and Krav Maga.As the player progresses throughout the game, Ezio will get stronger and more skilled. He figures out more skills and ways to kill and disarm his opponents, and builds more muscle as he finishes fights and assassinations. i just copy and paste