Black Room of Death
A Black Room of Death, also known as a BRoD, is a term used to describe the area behind a loading zone door. They are intended to provide the illusion of continuity between two different loading zones.
Under normal circumstances, they are only visible behind their opening door. However, using glitches, Mario can access all Black Rooms of Death. Despite the name, Black Rooms of Death do not kill or harm Mario, though one side in Cool, Cool Mountain has no tangible floor, and two others are inescapable without Hyperspeed.
Interestingly, entering a Black Room of Death's door from the wrong side will send Mario to the corresponding Black Room of Death in the other loading zone, which inexperienced players sometimes consider an inescapable situation. However, many pairs of tangible Black Rooms of Death have at least one escapable room. Mario can usually escape these by jumping at the wall surrounding the room's door.
There are 6 pairs of Black Rooms of Death in the game. This video shows all of them. The following table summarizes information about each room:
| Location | Screenshot of Side 1 | Screenshot of Side 2 | Mode of Access | Side 1 Escapable? | Side 2 Escapable? |
|---|---|---|---|---|---|
| Behind the Castle's entrance door | 
|
|
|
No | Yes (by jumping through the wall) |
| Behind the door to the Courtyard | 
|
|
Hyperspeed (both sides) |
No | Yes |
| Behind the door to the 2nd Floor | 
|
|
Hyperspeed (both sides) |
Yes (by BLJing under an invisible wall) | Yes (by jumping through the wall or triple jumping through the ceiling) |
| Behind the door to the Basement | 
|
|
|
Yes | No |
| Behind the Moat Door | 
|
|
|
Yes | No |
| Behind the door at the bottom of the Cool, Cool Mountain slide | 
|
|
|
No | N/A (no tangible floor) |