Super Mario 64's Secret Door Is Finally Opened After 28 Years Without Any Mods

mario code
Super Mario 64 is one of the most beloved video games of all time, and it's also one of the most thoroughly dissected video games of all time. There's a complete recompilation for PC including dozens of mods that allows players to add new areas, entities, and mechanics, play the game with ray-traced graphics, or even play entirely new games in the same engine.

The 28-year-old game's mechanics were well understood long before that existed, though, thanks to the efforts of speedrunners like the legendary pannenkoek2012. You've probably heard of this fellow before; he's the man who became infamous for introducing the concept of the "half A-press" to Mario 64 speedrunning.

mario speedrun

One of the most enduring mysteries surrounding Super Mario 64 has centered around a door in the Cool, Cool Mountain world. You see, you start Cool, Cool Mountain at the top, and right near the start area there's a building you can enter. Doing so will put you inside an indoor area with a large slide that takes you to a similar shack at the bottom of the mountain. However, the door out at the bottom is a one-way door; once you leave, you can't come back.

mario hitboxes
You have to be both walking and inside the red circle to open the door.

Except it's been known for some time that the door actually isn't a one-way door at all. There's a functioning door entity there; you just can't reach it because the hitbox for the wall pushes you away. Clipping through the walls in Mario 64 isn't exactly difficult, but there's another problem: there's no ground inside the shack if you enter from the outside. Clipping through simply causes you to fall to your doom—there's no way to activate the door.

mario alexpalix demo

As you've no doubt guessed, an enterprising player has now figured out how to use the door. User "Alexpalix1" on Discord posted a short video demonstrating how to do it. The method is fairly simple, and combines two known techniques—a clip exploit involving the penguin mama, and a "turn around" frame exploit in Super Mario 64's code.

By activating a "turn around" animation in mid-air, Alexpalix1 was able to trick the game into triggering the door animation just as Mario enters his free-fall. As pannenkoek2012 explains quite succinctly in his video, Mario still passes through the kill plane that would normally force him to reset, but because he's in the door opening "cutscene" animation, it doesn't affect him, and he passes through the door normally.

Amusingly, this exploit turns out to be largely pointless because it doesn't actually save any time over the current method of getting the star it unlocks. The player still has to get to the bottom of the mountain, and dealing with the penguins takes more time than it requires to exit the door from the inside. It's still a fascinating trick, and very well explained in the video, which we've embedded above.