This article is about the place. For information about the game, see here.
Luigi's Mansion is a mansion that appeared out of thin air. It is the main setting of Luigi's Mansion.
Luigi wins the mansion in a contest he doesn't enter. He invites Mario to celebrate with him, but Mario is mysteriously missing by the time Luigi arrives. Luigi looks around the foyer until a strange orange glow around a floating key catches his attention. The glow quickly vanishes, and Luigi uses the key it dropped to access the Parlor. There, Luigi meets Professor E. Gadd battling a Gold Ghost with the Poltergust 3000. It breaks free, and, after a brief meeting between Luigi and E. Gadd, returns with two more Gold Ghosts. Outnumbered and unprepared, the two flee to The Lab.
Luigi returns to the mansion with the Poltergust 3000, tasked with finding and capturing several ghosts that were freed from E. Gadd's portraits while he searches for his brother. Luigi is called out of the mansion periodically to return these ghosts to E. Gadd, who uses a special machine to turn them back into portraits. While exploring the mansion, Luigi accidentally releases a swarm of boos and their leader, King Boo. When King Boo sees the Poltergust 3000 on Luigi's back, he orders the boos to flee.
It isn't long from there until Luigi finds Mario. While exploring the courtyard behind the mansion, he climbs down a well and travels through a small hallway. He reaches a narrow spot at the end of the hallway that he can see through into a strange room. There, he sees Mario trapped inside of a portrait in the end of a room, as well as King Boo admiring the portrait, though he has no way to access the room at the time and, subsequently, no means of saving Mario.
Luigi is eventually able to work through the mansion into the basement, where he finally finds the door to the room he saw earlier. He enters the Secret Altar, where his final confrontation with King Boo takes place.
A large majority of the game takes place inside the mansion, and many mechanics in the game are tied to it. Most of the game revolves around exploring and defeating ghosts in various rooms around the mansion, many of the doors to which are initially locked. This forces Luigi to explore other rooms to find keys. Every key is specific to a certain room, meaning keys cannot be used interchangeably. Certain doors require special keys. Doors like these divide different parts of the mansion into different areas, and the keys for them are obtained by defeating special area bosses.