(Image credit: Nintendo)
A significant breakthrough in the 2D Mario speedrunning universe was unveiled, thanks to an accidental gameplay clip shared by a casual enthusiast.
On March 13, a user named Luigi’s Sidekick uploaded a series of clips on Twitter while navigating through the Japanese Super Mario Bros. 2 – internationally recognized as The Lost Levels – via the Nintendo Switch Online NES library. In one notable clip, during the final stage, 8-4, the game unexpectedly crashes, displaying an error message before abruptly returning the player to the game selection screen.
For several weeks, the clip went unnoticed until it caught the attention of Mario speedrunners, who realized the crash could be a gateway to executing arbitrary code execution (ACE). This glitch effectively sets SMB2 searching for code in unintended areas and, by carefully tweaking memory segments – like adjusting enemy positions or scoring specific codes – players could essentially trick the game with a ‘cheat code’ to jump to the end.
Speedrunner Kosmic, known for debunking the myth of Donkey Kong’s so-called ‘kill screen’, humorously suggested it might take several months to decode this phenomenon. For a condensed explanation: “If the object slots are arranged a certain way, the long firebar can load into out-of-bounds memory,” Kosmic elaborates. “Repeating the process allows out-of-bounds interference, potentially crashing the game unless executed with precision to triumph.”
Within days, Mario speedrunners recreated the glitch and devised a method to employ ACE to fast-track to the end of SMB2. Kosmic shared a Twitter clip of fellow runner threecreepio‘s workaround, hailing it as “The Biggest 2D Mario speedrun discovery in years.” Although tool-assisted due to its complexity, the community remains optimistic about finding a feasible approach for live execution.
However, this ACE trick is confined to level 8-4, the game’s final stage. While it may only shave off 10 to 15 seconds, this reduction is substantial for such a well-explored game. The longstanding world record, set by Niftski in 2022, might still remain intact since the any% category could split into ACE and non-ACE if a human-practical method emerges.
“I genuinely can’t believe a random crash I had with this game actually helped discover a new speed run trick,” Luigi’s Sidekick remarked on Twitter following the revelation of the ACE exploit. “How the hell did I do that?”
An intriguing tidbit: the crash takes place as Mario falls into a lava pit while clashing with a castle wall – the very scenario depicted on the North American cover of the original Super Mario Bros. As some viral tweets amusingly point out, Nintendo inadvertently delivered some exceptional foreshadowing.
It took 490 days, but the Super Mario Bros. speedrun world record is now four frames better – just 18 frames shy of utter perfection.