How a Backwards Long Jump Builds Speed
A Backwards Long Jump, or BLJ, starts with an ordinary long jump performed while Mario is moving backward. On the Endless Stairs in Super Mario 64, a runner repeatedly jumps backward into the steps. Each landing and renewed jump can add to Mario’s backward speed instead of bringing it back to a normal running pace.
The important quirk is that the game handles this backward movement differently from ordinary forward running. Its speed calculations do not impose the same effective limit, so repeated jumps can make Mario’s backward velocity grow far beyond what the level was designed to accommodate. “Infinite speed” is a convenient shorthand, not a literal endless value: the game is still doing finite calculations, and the result depends on the setup and timing.
Why the Stairs Stop Stopping Him
The staircase normally keeps Mario from reaching the upper castle area until he has enough stars. At ordinary speeds, the steps and surrounding surfaces reliably contain his movement. At BLJ speed, however, Mario can travel an unusually large distance between the game’s movement and collision checks. That creates a chance for him to pass through a surface rather than be stopped by it—a familiar kind of failure in games, often called tunneling.
Once through the staircase’s intended barrier, Mario can reach areas that the star requirement is meant to keep inaccessible. The glitch does not erase the requirement or magically unlock the castle; it exploits the gap between how fast the game moves Mario and how often it checks whether he has hit something.
That is why the BLJ is more than a funny animation: a small, repeatable input sequence exposes a mismatch in the game’s movement and collision logic, turning a staircase designed to hold players back into a route through the castle.
