Luigi's NEW Mansion (also called Luigi's Palace or Luigi's Fortress) is a mansion that first appears after defeating the final boss, King Boo, in Luigi's Mansion, taking place of the original spooky mansion. The new mansion's design is based only on the amount of money that Luigi collects throughout the entire game. If Luigi gets a Rank A, the mansion will look like a magnificent palace with an "L" mark on it. From Rank B and below, it will progressively get tinier. Note that if the player gets a Rank H, the "mansion" will just be a tent.
In the 3DS remake, the ranks stay the same, but each mansion is redesigned a bit. Additionally, a new S-Rank mansion is added which requires the player to collect over 130,000,000G while playing the Hidden Mansion to obtain.
- S Rank: Finish the game at or above 130,000,000G. 3DS version's Hidden Mansion only. The S-Rank mansion appears less like a mansion and more akin to a luxury hotel with multiple fountains and water holes.
- A Rank: Finish the game at or above 100,000,000 (NTSC version) or 150,000,000G (PAL version) on GameCube, and from 100,000,000G to 129,999,999G on 3DS + Message: Congratulations! Your mansion is complete! In the GameCube version, the A-Rank Mansion appears tall and almost hotel-like in nature, with four stories. In the 3DS version, it appears far less angular and much livelier, with a small courtyard and fountain, and plenty of botany around the mansion itself.
- B Rank: Finish the game from 70,000,000 to 99,999,999G. + Message: Welcome to Luigi's NEW Mansion! (Also appears for Ranks C-G) In the GameCube version, it appears as a rather standard-looking three-story mansion. In the 3DS version, it more closely resembles a small domestic castle, with pronounces columns and spire-like chimneys.
- C Rank: Finish the game from 60,000,000 to 69,999,999G. On GameCube, the mansion resembles a luxury home fit for a medium-sized family. On 3DS it's even cosier, looking like a fancy cottage.
- D Rank: Finish the game from 50,000,000 to 59,999,999G. The GameCube version of the Rank D house resembles the 3DS Rank C house, oddly enough, just with a more bland presentation. The 3DS version is not too far off, appearing like a smaller version of the Rank C iteration.
- E Rank: Finish the game from 40,000,000 to 49,999,999G. The GameCube version resembles a small family house. The 3DS version is similar, bit it's mirrored and has a less-impressive sense of size.
- F Rank: Finish the game from 20,000,000 to 39,999,999G. The GameCube version is the last one to resemble a proper house, being a small, symmetrical home. The 3DS version begins shacking the homes here, as the F-Rank mansion appears as a very small, 1-person cottage.
- G Rank: Finish the game from 5,000,000 to 19,999,999G. Both versions of the F-Rank mansion are extremely small 1-room shacks, with the 3DS version looking even more exaggeratedly small.
- H Rank: Finish the game from 5,000 to 4,999,999G(s). + Message: The haunted mansion disappeared without a trace... Both versions are rather pathetic tents set up on the hill the mansion used to be on.
- The A Rank Mansion is seen in the background of Luigi's Circuit in Mario Kart: Double Dash!! and Mario Kart DS .
- The music, like the messages also vary, for the Rank A mansion, very beautiful music will play, for Rank B-G mansions, normal music will play, and for the Rank H mansion, deep, ugly music will play, along with a springy sound in the middle.
- Oddly enough, it is very difficult to get a Rank H mansion since the player will have to avoid a lot of money and it is impossible to completely avoid everything since King Boo's crown, which must be collected, values 5,000 G.
- The 'canon' Mansion ending seems to be The Rank D one, as it is similar to the one in Dark moon.