Invisible wall

An invisible wall is any area that Mario cannot move through that has no visible collision. There are several types of invisible walls in Super Mario 64. Some invisible walls are intentional and are used to keep Mario from entering certain areas. However, most invisible walls are the result of glitches relating to surface misalignments.

Intended Invisible Walls

Some invisible walls are intended, as a way to prevent Mario from moving into certain areas. There are two kinds of intended invisible walls.

Untextured Wall Surfaces

The most basic type of invisible walls are merely surface triangles with no associated texture. These are used in a few areas, such as the hallway before Bowser in the Dark World. Aside from having no texture, they behave identically to normal walls.

Out of Bounds on Course Edge

Another type of intended invisible wall is the out-of-bounds area. On courses without a death barrier, such as Bob-omb Battlefield, Mario is prevented from jumping off the side of the course by the out-of-bounds area. The out-of-bounds area is also present on the perimeter of courses with a death barrier, but is typically not as easily accessed due to the distance between the course and the edge.

Unintended Invisible Walls

Unintended invisible walls are those that are not in the game intentionally. Some occur as a result of Mario being in areas he is not normally able to reach, but most result from small gaps within level geometry. As invisible walls in the latter case are often sparse over a wide area and are often only 1 unit thick, whether or not Mario is blocked by them depends on Mario's exact position and speed.

Ceiling Hitboxes

Ceiling hitboxes extend upward until reaching a floor triangle above the ceiling triangle they are part of. If Mario can reach an area below the floor triangle but above the ceiling triangle, he will encounter an invisible wall made up of ceiling hitboxes. This can be reached in a few areas, such as the castle foyer, or by clipping into certain objects. If there is no floor triangle above a ceiling triangle, the ceiling hitbox extends upward indefinitely. Typically, these ceiling hitboxes extend into places normally unreachable by Mario, but a few occur within normal areas, such as above the second and third arches in the Tall, Tall Mountain slide.