In Mario & Luigi: Bowser's Inside Story, the characters are deathly allergic to wearing inappropriate clothing. If Mario and Luigi are made to wear Bowser's clothes or vice versa, all their stats drop to 0. It is unknown if this is merely a code quirk or an intentional failsafe.

In Super Mario Bros. Wonder, the Floating High Jump badge is called "Luigi" internally. This means the playable Luigi has to have a different name - "PlayerLuigi". Whenever Luigi wears the badge, it is actually PlayerLuigi wearing Luigi.

The programmers of the Donkey Kong arcade left a message in the code to hackers mockingly congratulating them and offering to teach them as a joke. A group of bootleggers actually took this seriously and contacted the company asking for help pirating their own game.

The Bowser in the Sky skybox from Super Mario 64 is well-known for its ominous appearance. However, it is actually made by combining real sky photos from texture libraries and then color-shifting them. Restoring the image from the original files shows it to be rather serene.

In Super Mario Galaxy 2, the cutscenes on Starship Mario are controlled by a giant floating L in a special cutscene dimension.

In Luigi's Mansion 2 HD, there is a cutscene where a Toad's face textures are shifted upward briefly. While he is facing away from the camera during this, looking at him from the front reveals he has two mouths and no eyes.

In Super Mario Odyssey, there is a single Luigi who is somehow too much for the Nintendo Switch to handle. Bringing the camera close to this 8-bit Luigi in Metro Kingdom at night will cause the game to stutter and slow down to 5 FPS. This is the only Luigi who has this effect.

In Mario & Luigi: Brothership, one of the lines a character says about Dorrie is a warning to not be its lunch. This is a reference to an infamous sign from Super Mario 64 warning of the same fate, which spawned urban legends that it would be possible to be eaten by Dorrie.

Mario & Luigi: Partners in Time contains an unused enemy called the Scoot Bloop, a Blooper whimsically wearing shoes. It has two attacks: a regular one and a "do nothing forever" attack where it just freezes in place and refuses to end its turn, trapping the player indefinitely.

Illustration from a 2023 patent granted to Snap Inc., the developers of Snapchat, showcasing an augmented reality effect that renders a dancing Mario over a user's video.

In Mario Kart: Double Dash, heavy racers are objectively better when racing against the player. While it may seem random which CPUs are the best in any given race, on the highest difficulties, the top team is actually guaranteed to contain one of the five heavy characters.

In a 1996 interview about Super Mario 64, Shigeru Miyamoto said he really wanted to make Mario throw MIPS the Rabbit by his ears, and would have done it if the team had just one more month.

Experimental post: Mode 7? What About Modes 1-6? Some games on the SNES, such as Super Mario Kart, boasted "Mode 7" technology. However, this raises the question of what happened to the previous modes. This post explains them and gives examples of their usage in Mario games.

Piranha Plants in Paper Mario: The Thousand-Year Door are the sleepiest creatures in the game, with some of their subtypes being up to 110% sleepy. This may be a reference to the famously sleepy Piranha Plants from Super Mario 64.

Super Mario Galaxy contains a variety of placeholder text. The placeholder for the screen when Mario returns to the Comet Observatory is particularly humorous, appearing to explain the Spin ability while repeatedly getting interrupted. Below is a mock-up of it displayed in-game.

Using a specific setup in Super Mario Maker 2, it is possible to create a "Negative Space Koopa Troopa". It will not only be invisible, but make objects behind it invisible as well, appearing as a walking hole in reality.

In Super Mario 3D Land, the welcome screen that is displayed when starting the game for the first time appears to be much less enthusiastic about the game in the European version compared to the US version.

"Fresh", sealed copies of Super Mario RPG actually have a unique title screen. This screen is lost permanently on that cartridge after playing and saving just once, and can not be restored without tinkering with the cartridge or waiting decades for the save battery to run out.

A glitch may occur in Super Mario Galaxy when played on a Nintendo Switch 2 whereby Mario will get stuck in freefall in the tunnel in Gateway Galaxy. The usual failsafe that would kill Mario for falling too long does not activate here, so Mario will tumble forever and never die.

Early concept art for the Super Mario Bros. Super Show suggesting the cartoon was planned to have animated public service announcements. While Captain Lou Albano did a similar PSA wearing a Mario hat ("if you do drugs, you go to Hell before you die"), that one was live-action.

While this may be obvious to some players, Cataquacks resemble Wiggler segments that have come to life. This is likely intentional due to them originating in Gelato Beach in Super Mario Sunshine, where the antagonist is a Wiggler.

The Donkey Kong Bananalysis stream continues! Please join me as I point out details and provide obscure information about Donkey Kong Bananza on the Supper Mario Broth Twitch channel! www.twitch.tv/suppermariob...

In 1999, the official Nintendo Australia site tested the visitor's ability to display Shockwave/Flash content by displaying a running Mario, crudely edited from a screenshot of Super Mario 64.

By changing only a single byte in the code of Mario Paint, the music composer will not stop at the end of the song and instead continue to play the entire contents of the console's memory as music.

Game & Watch Gallery 3 contains a debug mode that displays the game's graphics. However, due to an incorrectly loaded palette and using a black background, the sprites for Yoshi in the Egg game appear inadvertently unsettling when viewed in that mode.

Two well-known voice clips from Super Mario Sunshine are Mario saying "Aren't I done yet?!" and "There's more?!" in an exasperated way, long presumed unused. However, there is actually a way to hear them in-game, as they have a chance to play when he enters a level at low health.

In Yoshi's Island, a cave background sparkles, but only when Yoshi moves. This is achieved in an inventive way by making many 1-pixel "pinholes" in the background through which a field of stars is visible. The parallax motion shows the stars intermittently, creating sparkles.

In Super Smash Bros., the skeletons visible when characters are hurt by electric attacks are not tied to specific animations, and instead are a form that can be toggled on and off at any time, including in cutscenes. Below are excerpts of the game's intro, with skeletons.

In Super Mario 3D World, eight colorful star particles appear every time a Ground Pound is performed. An extremely rare event of all eight of them matching in color may occur with a less than 1 in 2,000,000 chance. No known recordings of this event exist.

Looking through binoculars around Moo Moo Meadows in Mario Kart World has a small chance of activating a "cute jumpscare" Easter egg whereby a group of Para-Biddybuds will suddenly look into the binoculars from the other side.

In the Super Mario Galaxy games, the staff credits text is always loaded into RAM despite not being needed until the ending. While horribly inefficient, this is inadvertently heartwarming as the games appear to honor their creators by keeping them in memory at all times.

Artwork used internally at DIC Entertainment during the production of the Super Mario World cartoon, replacing Marge Simpson with Mario. According to a former DIC employee, this was made due to an inside joke at the studio, though the exact nature of the joke has been lost.

Due to the unique way Super Mario Bros. stores its maps, its level designers were at the mercy of the decorative hills and bushes when placing bottomless pits. While the pits can be placed freely, the decorations are non-negotiable and dictate the level design.

Development files for Super Mario Kart show that the earliest sprite for Koopa Troopa did not have his eyes visible from the back, making him appear like an unknown bald man (left). The eyes were made prominent in the finished version to avoid this (right).

It's a new series of Supper Mario Broth livestreams! Please join me as I bananalyze details and provide obscure information about Donkey Kong Bananza on the Supper Mario Broth Twitch channel! www.twitch.tv/suppermariob...

In Donkey Kong Bananza, Void Kong's banana remote opens from the end opposite the stem. This is actually consistent with how apes and monkeys peel bananas in real life. While humans tend to peel bananas from the stem, monkeys peel from the opposite end.

In Super Mario Galaxy 2, Wild Glide Galaxy is "larger than the universe", going outside the boundaries of its own skybox. The game simply drags the skybox alongside Mario's position to keep the area immediately around him within the boundaries.

Due to a bizarre code interdependency in Super Smash Bros. Melee, specific combinations of opponents and stages exist that let Luigi start the match with his Luigi Cyclone move fully charged. Knowledge of the full matchup table can be used by sly players to gain an advantage.

The developers of Mario's Early Years for DOS customized the game for three of their children. Inputting hidden codes at the start of the game can launch it in a personalized "Marissa", "Ali" and "Josh" mode whereby the in-game voices address the child by name.

In Super Mario RPG, the Guerrilla enemy is a "knock-off" of Donkey Kong. This is referenced in a unique way by its Japanese name, which replaces two of its characters with similar ones as though on a bootleg product logo. In English, this could be conveyed as e.g. "Donkev Konq".

In Donkey Kong Bananza, DK's banana awareness is tied to how far the camera is zoomed out. If the bananas are offscreen, this can create the impression of him playing a silly game with the camera where he makes a funny face only when the player isn't looking closely.

In Yoshi's Island, a "tongue overflow" glitch exists whereby Yoshi's tongue is able to fly away and begin gaining infinite length, overwriting the game's memory. The tongue-based corruption can have any number of effects, including skipping to the credits and ending the game.

Experimental post: The Inevitable March of Time From the moment of this post, Super Mario Bros. is now closer to World War II than it is to the present day.

The Super Mario 64 source code lists names for Mario's footstep sounds. The list starts off normal but becomes poetic with names like "Footsteps in the Fallen Leaves" and "More Than Anyone Else in the World". It turns out the names are actually taken from a 1994 dating simulator.

In 2017, the U.S. government used a cover of music from Yoshi's Island DS on one of their websites, presumably without permission, as the music was removed immediately after this was publicly discovered.

In the character selection screen of Mario Kart Wii, the princesses have tiny biker versions of themselves hidden inside their bodies. This is due to the game loading both the dress and biker models at the same time for efficiency, and simply shrinking the currently unused one.

Super Smash Bros. contains a sneaky "delayed action" anti-piracy measure to lull the illegitimate user into a false sense of security. The game will be normal the first 68 times it is launched. Starting with the 69th time, however, every selected character will turn into Mario.

Experimental Post: Wiggler Wednesday I have compiled a collection of obscure facts about Wiggler in Super Mario 64.

In Mario Kart World, NPCs will park their cars, exit them, and walk around. However, the game does not actually keep track who each car belongs to. As such, a different NPC than the owner may drive away with a car, seemingly stealing it.

Development files for Yoshi's Island reveal that Yoshi was originally meant to have a human voice. Lines for transforming into his various forms, including unused ones like Tree Yoshi, have been found.