New Super Mario Bros Ace Trick Discovered After 40 Years To Break Speedrun Records

After an Arbitrary Code Execution (ACE) was found in the Japanese-only Lost Levels sequel, an ACE exploit has been found in the original Super Mario Bros. 40 years after its original release. Both glitches are only possible on the original Famicom Disk System hardware or emulators, since the memory of the Nintendo Entertainment System cannot be as easily rewritten, and presents an unbeatable Minus World glitch to its players. The process for this glitch is unrelated to the additional "lost levels" which can be found in The Lost Levels, but requires a similar high-level degree of game state manipulation and frame-perfect inputs.

The shortest possible route to an ACE that can clear the game more quickly (pictured above) still takes 5 minutes and 15 seconds—about 30 seconds behind the current World Record speedrun for Super Mario Bros, and over a minute behind the current Baldur's Gate 3 clear time. So it's unclear when, if ever, this discovery will make for a faster speedrun. Even if it did though, it would be relegated to its own category on the leaderboards. It does open a litany of other possibilities, however, since Arbitrary Code Execution and its prerequisites can change the game in some pretty fundamental ways.

In order to execute the ACE in Super Mario Bros., the player must first satisfy several prerequisites. It starts by beating the game once (which can be done more quickly by executing the Minus World glitch) and triggering a game-crashing object overflow glitch twice over. With the game beaten, all Goombas transform into Buzzy Beetles. The first Minus World in Super Mario Bros. features an endless void of spawning enemies after the first flag pole, and it's past these boundaries that performing the object overflow glitch, previously only possible in Lost Levels, becomes doable. However, since the first Minus World is also underwater, it's impossible to manipulate existing enemies in a way that would make them turn right—necessitating Second Quest status to replace Goombas with Buzzy Beetles that will always follow you in that direction.

Upon triggering the first crash, hitting Reset on the Famicom will allow you to perform the crash again, and execute from the PPU instead of main memory. If you execute the overflow glitch crash while walking with Fire Luigi on the right side of the screen when a glitched Bowser spawns, you'll get a version that instead of crashing the game, resets it into a state controllable by manipulating the height of the Blooper following you.


Resetting the game via the object overflow glitch at this point will result in all kinds of different game-altering effects. Most of them are purely graphical, like the intensely-shaded version of the title screen below.


Another interesting effect results in a continuous rain of coins from the top of the screen, which is similar to New Super Mario Bros. 2, a game in the series all about egregious coin overflow. While obviously not an intentional part of this game's design, it's interesting that a glitch buried deep within the code can trigger such a game state.


But it's within the triggering of these game states that the solution to ACE from memory is found. The correct Blooper height adjustment and object overflow reset can trigger a game state where spawning any powerup can then result in an ACE. ACEs possible from here include spawning the end screen, thereby beating the game, as well as virtually anything else you can imagine.


This discovery, found by Kosmic and other dedicated Super Mario Bros. speedrunners, is a historic achievement. Now, virtually anything in the game is possible. Past ACE examples include making it possible to inject entire additional games within existing titles. And on a meta level, what greater powerup could there possibly be than the ability to reprogram the entire game just by playing it?

Image Credit: Kosmic on YouTube