“Super Mario Bros.” has been completely broken? The strongest glitch in history confirmed

Value, but only for the research-focused crowd.

The speedrunning community has dug fresh meat out of an old bone in Super Mario Bros. Over forty years later, players have finally confirmed an “arbitrary code execution” exploit in this game. The meaning is straightforward: through an extremely complex sequence of inputs, you can rewrite the game’s behavior at runtime. In terms of results, you can one-click jump to the ending screen, essentially clearing the game instantly through technique instead of cheat devices.

The starting point was pure accident: someone triggered an abnormal crash in a castle level of Super Mario Bros. 2. After this short clip was posted in the speedrunning community, it was immediately treated as a newly discovered gold mine. Community players followed the clues and suspected this was a classic sign of ACE rather than a normal softlock. Previously, similar exploits had been used to duplicate items in the Pokémon series, so veteran players are familiar with the term. The difference is that this time the target is Nintendo’s most iconic legacy IP, so the historical significance is on a completely different level.

After that, Kosmic took the lead and simply aimed directly at the original Super Mario Bros. itself. The team revisited old mechanics like Minus World, and then layered on bizarre interactions between enemies and items. The conclusion is already in: this ACE exploit does exist, and it can be reproduced reliably. The theoretical ceiling is very high—entering any world, any level is not a problem in principle. To quote their own words, “arbitrary code execution” has now truly been written into Mario history.

But if you’re an average player, the practical value of this is close to zero. The trigger process is absurdly long; the setup takes far more time than simply beating the game normally. The precision required is almost laboratory-grade—off by a single frame or a single pixel and it fails. Kosmic himself said this doesn’t really help with current speedrun records. Even if the rules allowed it, such an unstable and extremely hard-to-execute route would never become a mainstream strategy.

From the perspective of the speedrunning ecosystem, this is more like a dividing line between eras than a new speedrun weapon. Old games are being mined with increasing granularity; we’ve gone from looking for shortcuts to directly rewriting the rules themselves. This is different from the early focus on “human mechanical limits” and is closer to reverse engineering. In the future you’ll see more classic cartridges being treated as computers to be studied, rather than just games to be played. From this angle, Super Mario Bros. has simply been pushed back onto the lab bench.

If you’re a collector, this news will only make the game feel even more valuable in your heart. If you’re a speedrunner, this is a new holy grail, but one that most people shouldn’t touch. For ordinary players, there’s just one takeaway: don’t expect new gameplay—treat it as watching a technical performance. What truly deserves attention is the fact that, forty years later, there are still people willing to take an old game apart to this degree.