The Gold Split Newsletter - Week #39 - Mario's Next ACE

The Gold Split offers a free, weekly digest of news from the world of speedrunning and beyond.

This Story of the Week is all about the discovery of a new glitch in Super Mario Bros.: The Lost Levels and was featured in this week's issue. The full post includes more news, briefly, as well as event news and this week's top times. Check it out HERE.

Story of the Week ✨

Super Mario Bros.: The Lost Levels (TLL) is a sequel to Super Mario Bros. It was released as Super Mario Bros. 2 in Japan in 1986 and initially deemed too difficult for the North American market. Only seven years later, it made its debut in the West as part of the Super Mario All-Stars compilation on the SNES.

The best players are already able to complete the game in less than eight minutes, but for the past month, speedrunners and TAS creators of the game have been musing about a new way of crashing the game that was discovered in March 2025, almost 39 years later. The end result is a method of performing a glitch called Arbitrary Code Execution (ACE) that yields a 17-second saving during the final level of the game. For a speedrun as optimised as this, that’s huge.

Arbitrary Code Execution

Broadly speaking, ACE implies a way to inject custom code into the game, often through regular controller inputs, and then execute it. This can be done by manipulating the game’s memory and writing code through a complicated and precise series of movements. Executing the code can have almost any desired effect, including warping the player straight to the credits.

Some players call it the Holy Grail of speedrunning, but for others it’s a curse they’d rather not see on the leaderboards at all. On one hand, more often than not it becomes the fastest way to complete the game. On the other hand, the gameplay that players originally fell in love with, the main reason they enjoy replaying the game over and over again, may feel barely recognisable. Thankfully, at the time of writing, the possibilities of its application in Super Mario Bros.: The Lost Levels are still a lot more limited.

For the most impressive display of what ACE can do, look no further than TASBot’s showcase at SGDQ 2022, put together by Sauraen, @Savestate, dwangoAC, and countless members of the community:

Discovery

On March 13, 2025, Twitter user LuigiSidekick posted a clip of Super Mario Bros.: The Lost Levels crashing while playing on Nintendo Switch. It’s worth noting that this person is not involved in the speedrunning scene, and so the clip took a few weeks to be noticed. Quite frankly, it’s a miracle that it was at all. Anybody (me included) not extremely well versed with Super Mario Bros. speedrunning would just disregard it and shrug it off. Games crash all the time for a variety of reasons.

However, some people are built different. On March 28, @Simplistic6502 was the first to replicate the crash with an emulator, research its cause and recognise its potential. On the Super Mario Bros. speedrunning Discord, this gained traction quickly and led to extremely technical and daily discussions about the possibilities: using inputs to skip to the end of a level.

Many members of the community collaborated and iterated quickly after each new discovery. They realised that the only level that makes ACE possible is the final one, 8-4, and quickly went from artificial recreations into proof-of-concept demos and a tool-assisted speedrun incorporating the glitch. The final frontier was always an RTA-viable setup that is possible to be executed by a human during a full game speedrun.

@threecreepio, @LeKukie and @Niftski were the first to come up with one, and @Niftski was the first to pull it off; not in a full run, but in 8-4 exclusively.

How it works

In this explanation, I won’t go beneath what I truly understand, but there are several levels of complexity, and this is just the tip of the iceberg. Furthermore, it relates to the setup at the time of writing. Over time, the way it is executed is going to change.

Super Mario Bros.: The Lost Levels stores objects in six memory slots. These include things like enemies, but also spawned coins, power-ups, firebars and fireballs. Immediately after those six slots is a two-byte value the game later uses to decide where to jump at the end of the room. Through the introduction of a seventh entity, the player can overwrite that value. In order to even spawn a seventh entity, it’s important that a second controller is also connected, continuously holding down the B and Select buttons. This stops the game from clearing the slots.

It’s relatively easy to cause a crash this way, but through a series of frame-perfect inputs and precisely positioned fireballs, players can write the two bytes which equal the address of the code that shows the credits. When the room ends (in this case through Mario’s death in the lava), the game skips the rest of 8-4 and jumps to the end.

Just today, @Niftski was the first person to successfully pull off ACE in a real run, saving more than 12 seconds over his previous world record.

Knock-On Effects

In the grand scheme of things, and as far as other ACE discoveries are concerned, this one is a relatively small timesave. However, it is now the fastest way to beat the game using the general definition of speedrunning: reaching the end of the game, usually the credits, as fast as possible and by any means necessary.

These are still early days for the glitch and it’s unclear how much the setup will improve in the weeks and months to come. If it becomes easy enough to learn and execute, it might be adopted by the majority of the community and not much would change. Any% would still remain the main category on the official leaderboards.

However, it’s much more likely that the community will ultimately opt to split the categories. Whether ACE would remains a part of Any% and a new category without ACE is created or if skipping to the credits becomes its own category and banned from Any% will be the result of longer discussions.

Considering other Super Mario Bros. games, it’s unlikely that this particular way of achieving Arbitrary Code Execution and skipping to the end will spread to more of them. It’s hyper-specific to TLL and relies on its memory organisation and level layout. However, given what I’ve already seen and how little I truly understand of the subject matter, I hesitate to make a definite judgement.

Further Reading

For more technical explanations, I highly recommend checking out the author notes for the latest tool-assisted run on TASVideos.org as well as @Niftski 's explanation video about the setup used and all its frame-perfect tricks.

If you’d like to join the fun yourself and have questions, there’s no better place than Super Mario Bros. Speedrunning Discord Server.

Thank you for reading! If you're curious about more of this week's news or would even consider subscribing to the newsletter, you'll find the full post over HERE.

Finding new stories to cover can be challenging. I encourage you to think about what happened recently in the communities you are a part of. If there are any stories, articles, glitches, events, or other topics I should be taking a look at, go ahead and submit them here or on the Gold Split Discord! 📨