In the game, players assume the role of an assassin known as Agent 47. The game advances as players carry out contract killings by solving puzzles to arrange for stealthy, untraceable assassinations.
Gameplay: Hitman 2 features mission-based gameplay. On each level, the main character, known only as 47, is given a set of objectives to complete. Most levels require the assassination of one or more people. However, how missions are completed is up to the player, and there are almost always a variety of ways to complete missions. Instead of simply running and gunning through the mission, one can set traps, like poisoning a drink, to terminate the target in silence. Some missions have assassination possibilities unique to the level.
47 can find disguises or remove them from an incapacitated person to blend in with his surroundings and access restricted areas. This plays in with the "suspicion" system; a bar beside the health meter on the HUD represents how much suspicion 47 garners. There are multiple ways to blend in more effectively; for example, the player can make sure to carry an AK-47 assault rifle while disguised as a Russian soldier. Despite the usage of a uniform, being nearer to fellow guards will simply increase the suspicion as they would have an opportunity to more closely examine 47. Also, running, climbing and being in restricted places are other ways to garner concern.
47's cover can be blown if suspicion gets too high, and the disguise will no longer be of any use. It is possible to switch between multiple disguises throughout the level.
Hitman 2 also uses the concept of a post-mission ranking system, in which the player is given a status based on how they completed the mission, rated along a stealthy-aggressive axis, between "Silent Assassin," a stealthy player who manages to complete the level without being noticed and only killing two non targeting people excluding the intended target(s), and "Mass Murderer," a non-stealthy player who kills everyone. The game rewards the player for critical thinking and problem solving, encouraging the player not to treat the game as a simple shooter. Achieving Silent Assassin status on multiple missions rewards the player with bonus weapons. These weapons, plus items found in previous levels, can be carried over into future ones, allowing for differing means of accomplishing the tasks. Big weapons like rifles and shotguns cannot be concealed, thus the player has to either be wearing an appropriate disguise to match the weapon, or make sure no one sees the player use it.
Agent 47 has left behind his life as an assassin and retreated to a church in Sicily to seek peace. He works as a gardener for Father Vittorio, his best friend and mentor. 47 attends a confession to admit his sins, but Vittorio understands and believes 47 is decent at heart. Father Vittorio is kidnapped and a ransom note is left for 47. 47 decides to go back to his old job as an assassin to track down Father Vittorio. He contacts his agency, who thought he was dead, and makes a deal with his handler, Diana. He will work for them if the agency can help him locate Father Vittorio. They accept the deal.
Diana informs 47 that Father Vittorio was kidnapped by a Sicilian Mafia capo named Giuseppe Giuliano. The man is holding the priest in a cell under his mansion, dubbed Villa Borghese. 47 infiltrates and kills Giuliano, but fails to find his friend. He is later told that a satellite image shows Father Vittorio being taken away by 'Russian-looking types in uniform'.
47 works with the Agency to repay their attempt to find Vittorio. After both sides are satisfied the deal is fulfilled, 47 negotiates for a pay raise and continues to accept contracts. He travels to different countries, including Russia, Japan, Afghanistan, Malaysia and India, to carry out his missions, assassinating the assigned targets ranging from terrorists and criminal bosses to enemy agents and generals. Eventually 47 gives up his search for Vittorio, believing him to be dead.
47 eventually learns that Vittorio's kidnapping was a ploy orchestrated by Russian mafioso Sergei Zavorotko, the brother of one of the men 47 was cloned from, to lure 47 out of retirement. Zavorotko, who has ties to the Russian government and military, had recently purchased a nuclear warhead on the black market and needed to silence everyone involved in the deal; all of 47's targets were individuals involved in the transaction, and Zavorotko was responsible for hiring 47 on all of the jobs. 47 attempts to kill Zavorotko, but is ambushed by 17, one of the prototype clones made before 47. 47 kills 17 and pursues Zavorotko back to Sicily, where he is using Father Vittorio as a lure to draw 47 out into the open.
Infiltrating Vittorio's church, 47 discovers it being patrolled by several of Zavorotko's henchmen. 47 kills them all and eventually corners and kills Zavorotko as he holds Father Vittorio hostage in the church's confessional. Vittorio gives 47 his rosary and begs him to follow a good path. 47, having decided he is incapable of finding inner peace, leaves the rosary on the church door and resumes his life as a hitman.