The game that started the Hitman franchise. The protagonist is a talented yet nameless hitman, known only by his code number 47. He has no past, as he is a clone created by a mad scientist. In the beginning, 47 is being held in a mental hospital, before he escapes to become a killer for hire. His job is to eliminate high-ranking mafia bosses for large sums of money while attracting as little attention as possible. His missions may initially seem unrelated, but the plot eventually ties everything together.

Hitman has to use precise timing, unconventional tactics, and stealth skills to get to his targets and neutralize their bodyguards. He can attack from behind, use sniper's rifles, machine guns, or even improvised weapons, such as a halter. There are usually many ways to accomplish every murder. An important part of the gameplay is disguise: Hitman can attack people and steal their clothes to blend into any environment. Dead or unconscious bodies of Hitman's victims can be dragged away and hidden to avoid raising an alert. Money earned from previous missions can be used to buy additional killing equipment. Hitman may also lose a part of his reward if he kills civilians on a mission.