Super Mario 64 · Nintendo 64 · 1996 · Speedrun Staple · Discovered by Community
Repeatedly long-jumping backwards on specific staircases causes Mario's speed value to overflow the game's signed integer, launching him at extreme backwards velocity and allowing him to pass through locked doors — enabling completion of the game with zero stars.
The Backwards Long Jump exploits a speed accumulation bug in Super Mario 64's movement physics. When Mario long-jumps backwards on staircases with specific geometry, each step contact adds velocity in the backwards direction without the normal speed cap applying correctly. After sufficient repetitions — typically fifteen to thirty jumps — the speed value exceeds the maximum storable in the game's signed 16-bit or 32-bit representation and wraps around to a large negative value, which the engine interprets as extreme reverse velocity. At this velocity, Mario passes through solid geometry that would normally block movement, including the star-count doors that gate progression through the game. The most famous application is bypassing the door to the basement, which normally requires thirty stars, and subsequently bypassing the door to the upper floors without the eighty stars the game demands. Speed-runners use these bypasses to complete Super Mario 64 in the "0-star" category — finishing the game without collecting any power stars — a run that typically completes in under seven minutes. The BLJ became the signature technique of Mario 64 speed-running and is sufficiently well-known that it appears in cultural references to the speed-running community at large.
Super Mario 64 stores Mario's horizontal speed as a signed integer — a value that can represent both positive (forward) and negative (backward) numbers up to a fixed maximum magnitude. Staircase geometry interacts with the backwards long jump in a way that adds velocity on each step contact without correctly applying the engine's speed limit. As the speed accumulates across repeated jumps, it eventually reaches the maximum value the integer can store. Adding one more increment causes the value to "wrap around" to the largest possible negative number — a consequence of how binary arithmetic handles overflow.
The engine then applies this extreme negative speed to Mario's position each frame, moving him backwards at a rate that the collision system cannot fully process. Solid geometry that would normally stop movement is traversed because the position update moves Mario so far in a single frame that the collision check — which samples positions along the movement path — misses the wall entirely. The game was not designed to handle speeds of this magnitude and has no mechanism to prevent the overflow.
The 0-star category created by the BLJ is a philosophical statement as much as a technical accomplishment. Super Mario 64 was designed around collecting power stars as the central activity; the game's entire progression system is built on the assumption that stars must be earned. A run that completes the game without any stars inverts this assumption entirely, using the game's own physics against its intended structure. The 0-star category has attracted some of the most technically skilled players in the Mario 64 speed-running community, and its current world record is measured in minutes and seconds rather than hours.
The BLJ's cultural penetration extends beyond the speed-running community. The distinctive visual of Mario accelerating backwards on a staircase before vanishing through a door has been referenced in speedrun documentaries, mainstream gaming journalism, and social media content. Nintendo's Super Mario 3D All-Stars (2020) and Nintendo Switch Online versions of Mario 64 patched the BLJ by modifying staircase physics — a rare instance of Nintendo retroactively addressing a speed-run exploit — which prompted community discussion about the ethics of patching historic bugs.