As you move through the city crowds, you must constantly be aware of the amount of commotion you're causing. Beggars and drunken troublemakers test your patience and threaten to blow your cover. You can beat them down if you wish, but too much commotion triggers the attention of the guards, and the situation can quickly escalate from fisticuffs to murder. But if you work the crowd and the surroundings properly, situations can be diffused without resorting to violence. The crowd can even be turned against the guards in neighborhoods where you've helped people fight back against corruption in optional Save Citizen missions.
Doing Save Citizen missions will unlock advantages in the corresponding area of the city. If the citizen you saved is female, her husband and his gang of friends will attack any guards who are chasing you through their neighborhood.If the citizen you save is male, a crew of Monks will circulate through the neighborhood for you to blend in with. Though the Save Citizen missions are completely optional, they make evasion much easier. While you are free to choose how you interact with the public, Ubisoft pointed out several times that Assassin's Creed is not a "mass murder game" - you are penalized for killing civilians. If you kill too many in a short period of time, the game will simply stop and revert you to a save point.
