List of Luigi's Mansion glitches
This is a list of glitches in the game Luigi's Mansion.
Bouncing Ball glitch
This glitch occurs in the Nursery when the player picks up the ball with , faces a wall, and then presses and holds . The ball will be bouncing off the wall and back onto the grasp of the Poltergust 3000 repeatedly.
Hanging Luigi Glitch
This is a lighting glitch in which Luigi's shadow appears to be floating whenever lightning strikes. This glitch has been mistakenly thought to be an easter egg apparently showing that Luigi hung himself. Though this has been debunked by that fact that it appears multiple times throughout the game in awkward places. It is caused by abnormal camera angles in select situations. It can sometimes be seen when talking with certain Toads, as well as when speaking with Professor E. Gadd over the Game Boy Horror in any room lightning can be seen, as well as in the Telephone Room while speaking on one of the telephones.
Invisible Bowling Ghost
This glitch randomly occurs and it makes a Bowling Ghost invisible. The bowling ball it carries will be floating above a pulsating ring that all ghosts have underneath them. It appears the ball has no collision detection when this occurs. 
Invisible Door glitch
When the player comes out of the Twin's room and presses , Luigi will perform the animation used for opening doors.
Map Clipping glitch
Out of Bounds glitch
This glitch occurs when the player rushes to the chest containing the Area 2 Key after defeating Chauncey before it finishes spawning. It will allow Luigi to walk on the ceiling. This glitch is commonly used by speedrunners as a method to complete the game as it has the ability to take Luigi to the final boss, King Boo, very early on into the game.
In order to achieve this, the payer must have side-step enabled from the starting point. After moving to the right, Luigi will run into an invisible wall. It's here that the player must press and Luigi will do a walk. Eventually, Luigi will open a door. The player must turn the light around so a Purple Bomber or Ceiling Surprise can't scare Luigi. The player will then see bats, and must make the bats notice him. Before Luigi gets hit, the player must hit down-right on . As soon as Luigi makes the "hurt" noise, the player must release . This will cause Luigi to be in a sideways angle. The player must hold right on both and , and if the angle Luigi is in is sharp enough, Luigi will go around a ledge. If Luigi's angle isn't sharp enough, he won't go around, and if that's the case, Luigi can enter a door and exit, and the bats will respawn. If down right, Luigi must then go down the hallway to the rooms including the Conservatory , while walking backwards due to some ghosts scaring Luigi. The player must then go to the left and try to vacuum some bats, but instead bring them to the right most area, and while doing so, the player must release , while quickly tapping left on and briefly holding right on all in one sequence. Luigi should have a diagonal angle once more. Switching to Standard mode, Luigi should go and face the player, along with his light. The player must re-enter Side-step, hold up on both and . The player then must pause, switch to standard mode, and hold up-right on and press to continue while pressing to open the Game Boy Horror. If done right, Luigi should fall into the wall of the hall to the Secret Altar. It's hard to see, so the player must enter First-Person View on the GBH to see. If all done right, Luigi should enter the Secret Altar and fight King Boo early.
There are some catches:
Pushing Toad glitch
This glitch only works with the Toad on the balcony and the First floor Washroom. Luigi is able to push Toad around and once he does, if the player saves, Luigi will be teleported back to the Foyer.
Shadow Bogmire glitch
This glitch occurs when Luigi faces a wall just as a Shadow Bogmire is about to sucked in. The Shadow Bogmire will be stuck on the nozzle of the Poltergust 3000. The outline of the ball that was supposed to be the Shadow Bogmire is now stuck on the wall that Luigi faced. To end the glitch, the player will have to make Luigi get hurt, knock on a wall, or release .
When Luigi rushes towards the well in the Courtyard and a Ceiling Surprise scares Luigi, he may occasionally fall through the ground and land in an out of bounds area next to the well and will be unable to get out.