Many new features were introduced in Blood Money. These include the capability to climb through more obstacles, improved unarmed combat, the ability to use a non-player character (NPC) as a human shield with the help of a weapon (and to knock them unconscious afterwards), the ability to dispose of dead or unconscious bodies into containers, improved character animations, a new game engine, and the ability to upgrade weapons and equipment. Five of the featured weapons in the game, as well as assorted pieces of equipment such as bombs and armor, can be upgraded. Every level contains some method to make the target's death look like an accident; for example, tampering with someone's grill to make it explode when it is turned on, rigging a chandelier to fall on a target, or simply pushing the target off a balcony. There are also improvised weapons, such as nail-guns, a child's air rifle, kitchen knives, screwdrivers, stilettos, cane swords, fire extinguishers, hammers, and hedge clippers.
Also added was the "Notoriety System". If the player, during a mission, gets caught on camera surveillance or is witnessed committing murder, 47's notoriety will rise. Conversely, if the player executes the mission perfectly with none of the aforementioned events occurring, 47's notoriety will be minimal. However, if the only factor affecting 47's notoriety in a certain mission is the fact that he was recorded on CCTV, the player may enter the location in which the tape that recorded him is located, usually in disguise, and retrieve it, thus eliminating that factor; if the player retrieves the tape before being recorded, this eliminates the risk of being recorded in the first place. The higher Agent 47's notoriety is, the easier it will be for NPCs to identify him. Players may use the bribery system to negate accumulated notoriety. Notoriety gained in early missions will affect later missions. Earlier missions in which 47 has gained notoriety in can be replayed to reduce notoriety in later missions. The "Notoriety System" is not enabled on "Rookie" mode, the easiest difficulty setting.
At the end of each mission, a newspaper article is displayed about the hit, in which the content varies depending on the investigation results and the player's notoriety. It will detail the weapon most frequently used, how accurately it was used, the number of police, security, and civilians killed or injured, and if there were any witnesses. Any injured people will be counted as witnesses, who affect notoriety. Sketch drawings are also sometimes visible showing Agent 47's face, which grow progressively more accurate as 47's notoriety grows. The newspaper announces in the headline how many people were killed, whereas executing the target without any problems will simply have 47 as 'wanted by police'. The article's title relates to the player's mission rating. "Silent Assassin", in which one assassinates the targets as cleanly and quietly as possible and draws no unnecessary attention to themself, is the best rating possible. On higher difficulty levels, something as simple as 47 exiting the level in a disguise rather than his original suit will adversely affect the player's notoriety, as well as deduct $5,000 from their payment for the mission. As one advances further into the game, more and more newspapers containing the headline from the last mission will be scattered around levels.
Blood Money also improved the melee weapons system, allowing the player to lethally throw certain weapons at NPCs. Once thrown into anyone, however, the weapon cannot be retrieved. There is an exception for the hammer, which can be retrieved even though thrown into a victim. Also unlike previous games, melee weapons cannot be transferred to the player's inventory.
If 47 renders a NPC unconscious, either by using his syringe filled with sedative or knocking them out with close combat, they will not awaken for the entirety of the level until a security guard checks it, unlike previous games. In addition, if both uses of 47's sedative syringe have been used and the player does not wish to use close combat (which increases their violence rating and by extension affects their mission rating), the player may take the person they wish to sedate as a human shield and knock them out with their weapon.
47's ability to hide bodies has also been revamped. In previous games, 47 had to drag the body to a secluded area without "hiding" it, and either eliminate everyone who could possibly see the body where he left it or be quick enough to finish the mission before the next person entered. Now, 47 can dispose of unconscious or dead bodies in containers to hide them from view of guards. If the container's lid is closed, no NPCs or guards will look inside it, thus ensuring the body stays hidden and 47's cover is not blown. In addition, if 47 kills someone in an elevator by climbing through the hatch and strangling them, their body is also considered hidden, and cannot fall out of the hatch, thereby preventing it from being found. Some levels feature high level areas; it is possible to toss bodies over the side.
Blood Money introduced the concept of rival assassins to the storyline. The developers created the Mark Parchezzi character as a sort of foil to Agent 47, for he is "everything Parchezzi is not." The other "lesser" assassins were there to prove more able than "drug dealers or similar adversaries."
Plot
The game begins with a flashback to a terrible accident at an amusement park in Baltimore, Maryland; the negligent maintenance of a Ferris wheel caused it to collapse and kill 36 people. The father of one of the victims contacts the Agency to order a hit on the park owner, Joseph Clarence. After carrying out the hit, 47 receives a string of contracts from U.S. clients who are eager to utilize his services.
The bulk of the game takes place as flashback sequences that occur concordantly to the present day, in which a journalist, Rick Henderson, and the former FBI Director, Alexander Leland “Jack” Cayne, discuss 47's hits over the past year and a half (2004–2005). Rick arranged to interview Jack concerning the recent attack on the White House, but Jack's real intent is to discuss 47. He lies about many details, such as stating that 47 stole Dr. Ort-Meyer's cloning data to sell to the highest bidder, and that 47 was working with a group of assassins known as the Franchise to kill the Secretary of the Interior.
As the game progresses, it becomes clear that the Agency's employees are being gradually assassinated by the Franchise. The situation degrades to the point where 47's handler, Diana Burnwood, informs him that they are the only operatives left. Eventually, Diana shuts down the Agency and divides the remaining funds between them. After completing his final assignment, 47 is approached by an old acquaintance, CIA agent Carlton Smith, who 47 had rescued earlier. He offers 47 a high-profile mission, paid in a million dollars worth of diamonds, to prevent an assassination attempt on the President of the United States, Tom Stewart; the assassins are Franchise operative Mark Parchezzi III and Vice-President Daniel Morris. They both work for Alpha Zerox, a shadowy political organization that seeks to monopolize the cloning technology used to create 47. Since the President intends to legalize cloning, which would ruin their plans, they hope to replace him with the much more controllable Morris.
