L is real 2401

This mystery is considered solved.

Mario by the plaque on the courtyard's star statue in Super Mario 64

In Super Mario 64, the courtyard at the back of Princess Peach's Castle includes a statue of a Power Star, where Mario spawns from if he is ejected from the nearby course Big Boo's Haunt. The illegible writing on this statue's plaque became the game's greatest mystery for 20 years, spawning various urban legends.

"L is real 2401" has prevailed as the most widespread and infamous interpretation of the plaque. It is a recognizable way to refer to theories surrounding the statue, as well as the related claims of Luigi's presence in-game. However, an official statement from 1998 claims that the plaque is intentionally illegible and meaningless, and no convincing evidence to the contrary has emerged.

The texture for the plaque was reused in The Legend of Zelda: Ocarina of Time, which was based on the Super Mario 64 engine. In Super Mario Odyssey's reconstruction of the courtyard, the Super Mario 64 statue reappeared using the original model and its low-resolution textures.

While Luigi became a playable character in the Nintendo DS remake, Super Mario 64 DS, Waluigi's absence caused analogous rumors.

Disconfirmation

On December 2, 2016, Redditor b0nd18t posted an image of a letter they received from Nintendo of America on May 7, 1998. The letter contains the following official explanation of the plaque's inscription.

Many people think that it’s a hint that Luigi is in the game and it has something to do with a special code. The real answer is that the programmers put it in there as a joke. They thought people would try and try to figure out what it means. It doesn’t have any meaning at all.

IGN bounty

On November 13, 1996, video game website IGN noted the constant stream of fake strategies for unlocking Luigi, and offered a US$100 reward for an authentic unlock method. The bounty went unclaimed. No proof of Luigi's existence was forthcoming, as neither the Nintendo 64 GameShark nor emulators yet existed to fake it.

Theories

L is real 2401

The most common interpretation of the plaque's inscription was that the top line reads "L is real 2401", which comes with various implications and secondary theories.

Luigi

The perceived "L" in "L is real" was widely taken as shorthand for Luigi, reflecting the green L emblem on his cap.

Luigi was notably absent from Super Mario 64, having appeared in most prior Super Mario games, with the exception of the handheld Super Mario Land games. Evidently, players were surprised by, or doubtful of, Luigi's absence. In interviews, Super Mario 64 staff were open about plans to implement Luigi and the eventual removal of his assets, but this information went unknown to most players.

As with many rumors, some players likely wanted to brag about finding a secret character. They would have combined speculation on the plaque, such as the number 2401, with elaborate unlock methods, to try to make their claims believable and unfalsifiable. Other players may have legitimately expected to unlock Luigi later in the game—including after collecting every Power Star and finding Yoshi, a more recently introduced character—and thus let their imaginations run wild, or had their expectations taken out of context. Ultimately, these urban legends often specified Luigi being a playable character, as was planned, rather than a secret supporting character like Yoshi.

As Luigi appeared in later Nintendo 64 games, some hoaxes edited these character models into screenshots of Super Mario 64. Growing technical knowledge and game modification helped propagate unofficial models of Luigi that more closely matched the Super Mario 64 style.

Total number of coins

One rumor claimed that 2401 represents the total number of coins in Super Mario 64, and that collecting them all and returning to the statue would unlock Luigi. While collecting coins does unlock Power Stars elsewhere in the game, this rumor is false, as the maximum value of unique coins in the game is 2657. To the rumor's credit, it provides a ballpark estimate for this total.

As the game does not track coins individually, it would be trivial to collect a couple thousand coins by reentering courses to respawn the coins. This has likely been accomplished both intentionally and accidentally.

Depending on the criteria one uses, there is a wide variety of possible coin totals in Super Mario 64.

Contenders for total coin counts in Super Mario 64

Total	By metric	Notes
2657	Unique coins without duplication glitches	This total includes a few misplaced coins that are inaccessible without other glitches. Note that, if the game tracked the collection of individual coins, especially by designating each with a unique bit in memory as it does to track Power Stars, it is more likely that these misplaced coins would have been addressed and removed. One might also expect that coins would indicate whether they have been collected before, similar to collected Power Stars changing color.
3231	Sum of maximum saved coin high scores	After collecting a Power Star in a main course, the game checks for a new coin high score. The value in the coin counter is then saved as an 8-bit unsigned integer. The maximum value for this kind of variable is 11111111 in binary, which equals 255 in decimal. Larger in-course coin counts will overflow when saved. For example, if the player collects 256 coins, or 100000000 in binary, the high score is truncated to its lowest eight bits (00000000) and saves as 0. If infinite coin glitches could be performed anywhere, the total would be 3825 (15 scored courses × 255 savable coins per course). The true total is lower because several courses have no known infinite coin glitch. If the game tracked coin progress by summing the saved coin scores, this would be the maximum legitimate value.
11819	Sum of maximum coins obtainable within each course (NTSC)	In the NTSC version of Super Mario 64, the in-course coin counter is capped at 999. Of course, the game would not track this; when saved as a coin high score, 999 overflows to 231.
329499	Sum of maximum coins obtainable within each course (JP)	The Japanese version of Super Mario 64 has a typo in the game logic for capping the coin counter. When Mario exceeds 999 coins, instead of setting the coin counter back to 999, it tries setting Mario's lives to 999 instead. This was fixed for the NTSC version. Because the coin count is a signed short, its maximum possible value is 32767, which overflows to −32678 if another coin is collected.
∞		At this point, the data that the game tracks and saves is no longer being considered. A player can reenter courses to keep respawning coins, leaving no upper bound on the total.

Number of laps

Another rumor claimed that running around the statue 2401 times, or alternatively the castle grounds, would unlock Luigi. This may have been inspired by the method to defeat the Mr. I enemy, which appears within Big Boo's Haunt, accessed from nearby the statue.

The magnitude of this task likely made the rumor difficult to disprove. During such a long process, it is easy to lose count of the laps, and the inevitable lack of results could be blamed on an unnoticed mistake anywhere throughout the process. This seems to have been a common tactic to make rumors unfalsifiable, but it becomes less effective as one realizes that Mario games tend not to be designed with such repetitive or exacting sequences with no indication of progress.

L is real in Paper M

Some "L is real" believers read the bottom line as "in Paper M", lending the full interpretation "Luigi is real on 2-4-01 in Paper Mario". This theory claims that the plaque hinted at Luigi's role in Paper Mario, which released in North America on February 5, 2001, one day after 2-4-01.

This rumor appears to have been made after the fact, as the title "Paper Mario" was only finalized after Super Mario 64's 1996 release. It was originally Super Mario RPG 2, which was changed due to legal issues. It was still called Mario RPG 2 as of a 1997 interview with Shigeru Miyamoto. Super Mario Adventure was an intermediate rename. In Japan, the game was ultimately titled 「マリオストーリー」 Mario Story. Only its sequels imported the Paper Mario branding, starting with 「ペーパーマリオＲＰＧ」 Paper Mario RPG (Paper Mario: The Thousand-Year Door).

On top of the alleged release date being off by a day, Paper Mario had different release dates between regions, which the plaque does not reflect. It first released in Japan on August 11, 2000. Date formats also differ between regions. Where the United States has interpreted "2401" as a middle-endian date (mdyy), many other nations would not. Japan uses a big-endian yyyy年mm月dd日 format, so one would expect the plaque to write February 4, 2001 as "2001年02月04日", or at least "0124". This reveals a further North American bias in the rumor. It seems unlikely that the Super Mario 64 developers would try to announce a foreign release date for a second-party game coming half a decade later, for the sake of a barely legible easter egg.

As Paper Mario released late into the Nintendo 64's lifespan, the significance of Luigi's minor role in that game is questionable. After Mario Kart 64, the Mario Party series, Super Smash Bros., and other games, Luigi was already well-established on the Nintendo 64, despite his absence in Super Mario 64. Thus, the rumor was elaborated, claiming that the plaque alludes to Luigi's diary in Paper Mario, which foreshadows Luigi's Mansion, where Luigi takes the spotlight.

To do:

• Do the development cycles for Super Mario 64 and Luigi's Mansion overlap enough to render the double-foreshadow believable?
• Does Luigi's diary reference Luigi's Mansion in the original Japanese script?

Time attack

Some rumors claimed that Luigi would be unlocked by collecting every Power Star under a time limit. Ironically, Super Mario 64 is now well-known for its speedrunning scene. As of February 28, 2022, the world record for collecting all 120 Power Stars and beating the game is 1:37:50. Modern speedruns have presumably been optimized enough to discredit these rumors.

Eternal star

A secondary interpretation of the plaque texture was that the top line reads "Eternal star", a name that would later be used by the final Mario Party board. Though less useful for speculative purposes, this interpretation arguably makes the most sense as the plaque is on a star-shaped statue. The font used for in-game dialogue also appears to match the "Eternal star" reading to some extent. However, the spacing of the letters makes the line more closely resemble "E te rnal star".

Giant dead Dodongo...

Link reads a sign with the plaque's texture in The Legend of Zelda: Ocarina of Time

In The Legend of Zelda: Ocarina of Time, a sign using the same texture in the Dodongo's Cavern dungeon reads:

Giant dead Dodongo...
when it sees red,
a new way to go
will be open.

This is a hint for a nearby puzzle. The solution is to throw bombs at the eyes of a giant Dodongo head, making it "see red", to unlock a door.

Due to the reused texture, some players have attempted to relate this message back to the statue in Super Mario 64. Their reasoning is that a giant undead enemy, the large Boo in the same courtyard as the plaque, drops the entrance to Big Boo's Haunt when Mario, who wears red clothing, defeats it. Even if this stretch of a double meaning were intended, it would have been a roundabout way to tell players how to simply enter one of the main courses in another game.

To do: Can any connection be drawn from the sign text in the Japanese script?

Even in the case of an intentional connection, the Nintendo of America letter suggests that the writers would still have been deceiving players, not alluding to a real secret in the Super Mario 64 courtyard.

Pit Mario xy

While most of the widely spread interpretations concern the top line of the plaque, the bottom line as "Pit Mario xy" is attested in a "Super Mario 64 Mysteries Guide" by Josiah Plummer. Internally, the game uses the y axis as the name of the vertical axis. This reading suggests that the player have Mario fall into a bottomless pit on some Cartesian plane with a vertical component, presumably to unlock a secret. However, the only nearby place that resembles a pit is a fall in Big Boo's Haunt, which leads to the course's basement.

This reading of the inscription seems to provide just enough geometric information to remain unhelpful. As Super Mario 64 was designed around full, polygonal 3D, the world axes and coordinates themselves are invisible. Compare the previous, 2D Super Mario games, where a coarse pixel grid is grouped into tiles with uniform rotation. In Super Mario 64, even when players can intuit a plane with an xy orientation (external tools being required to confirm this), they cannot precisely constrain Mario's movement to it, especially with a camera system that rotates to point along the direction he travels.

Plummer's "Super Mario 64 Mysteries Guide" reasons, "If the text actually is a command to take Mario to a specific location, a z-coordinate is needed." However, the alleged text does not give an x or y coordinate, either. Even if it had, the game never indicates the units of its coordinate system. For a sense of scale, Mario's hitbox is 100 units in diameter and 160 units tall, much finer than pixel measurements that players at the time would have been used to.

If this reading is taken to refer to the xy plane that passes through the origin (0,0,0) of the game's coordinate system, there is still no way to find the origin without glitches:

• A cloned object can load incompletely, such that it appears at the origin and never moves to its intended location.
• So long as no held object has been rendered in Mario's hands since the game booted up, the player can drop an object at the origin; the game only sets the drop position in front of Mario once a held object is rendered. The object used must not render in Mario's hands before it is dropped, requiring further exploits.

Even using these glitches, the player would have yet to determine the direction of the x axis, and would have already strayed far beyond intended game mechanics in their attempt to find the xy plane.

Planned inclusion of Luigi

Even though Luigi does not appear in the final version of Super Mario 64, his inclusion was planned in earlier stages of development.

Satoru Iwata and Shigeru Miyamoto have confirmed that the game "started with Mario and Luigi running around together" in splitscreen and single-screen camera modes. Yoshiaki Koizumi later cited "a choice between cutting Luigi or making less elaborate landforms" due to hardware limitations.

According to a 1996 interview, Luigi was later planned for inclusion in a Mario Bros.-style minigame, since memory issues demanded he be removed from the main game. The Nintendo 64 being sold with one controller factored into the minigame being dropped, causing Luigi's total removal from Super Mario 64 by February 1996.

The fact that Luigi was planned to be playable may help explain why all traces of the character were removed, instead of Luigi taking on a supporting, non-playable role, as in Super Mario World 2: Yoshi's Island.

Leak of prerelease assets

In July 2020, fans reconstructed a prerelease model of Luigi from recently leaked assets.

As of July 25, 2020, source code and development assets for an early version of Super Mario 64 were leaked from Nintendo's servers. They contained the textures, model, and other assets for Luigi. This leak occurred around 24 years and one month after Super Mario 64 was released, which may have been coincidental to the phrase "L is real 2401", or perhaps intentionally timed by the leakers.

This leak of prerelease content is not to be confused with the final version's source code, from which Luigi cannot be reconstructed. In 2019, writing about the completion of the Super Mario 64 decompilation for Ukikipedia News, JoshDuMan stated:

• …where’s Luigi at? Legitimately, everywhere. All over the repository are unused arrays the have a Mario object as the first element of the array and an unused second slot. There are switches in some places depending on the player, but only contain references to Mario. Luigi was definitely in the game at some point and his shadows are all over the place. However, he can certainly not be recovered from the current code the codebase has.

After Super Mario 64, Luigi was planned to appear in its canceled Nintendo 64DD sequel, tentatively titled Super Mario 64 2. What little information exists on this sequel heavily suggests that Luigi would have been playable in multiplayer, just as was planned for the original game.

Luigi's inclusion in other games

In the Super Mario series, Luigi had previously been absent from Super Mario Land and Super Mario Land 2: 6 Golden Coins. This may have been overlooked in those games because they were handheld games with notable differences from the console Super Mario games, whereas Super Mario 64 was ambitious and for a more powerful console.

An overlooked commonality between the Super Mario Land games and Super Mario 64 is the lack of the word "Bros." in the title. Perhaps this could have lowered expectations for Luigi's inclusion. However, in many regions, Super Mario World had not retained its subtitle, Super Mario Bros. 4, and thus included Luigi despite "Bros." being dropped from the title.

Luigi was also absent from the following Super Mario game, Super Mario Sunshine. Interestingly, this seems to have spawned less speculation on his whereabouts. Fans may have learned from the Super Mario 64 theories, been sated by his recent lead role in Luigi's Mansion, or taken the premise and new setting of Super Mario Sunshine as a logical reason for Luigi not to appear. Still, there was at least one urban legend about collecting every Shine Sprite and fighting Waluigi as a secret boss to unlock Luigi.

Since the Nintendo DS era, Luigi has been unlockable in many Super Mario games. This may be an acknowledgement of the Super Mario 64 rumors, or of the underlying fan expectation for Luigi's presence.

Super Mario 64 DS made Luigi "real" as an unlockable character alongside Mario and Wario, which in turn spread similar rumors about Waluigi. In New Super Mario Bros., Luigi can be used in the Mario Game campaign with a secret button combination, which is revealed upon finishing the game but can be used earlier.

Luigi is unlocked after beating the game in Super Mario Galaxy, Super Mario Galaxy 2, Super Mario 3D Land, and New Super Mario Bros. 2. He was playable in Super Mario Bros. 35 after clearing every course, by holding the L button while selecting a course or mode.

Paralleling his absences from the earlier sandbox-style games, Luigi did not appear in Super Mario Odyssey at launch, despite the courtyard and star statue's return. He was added as a non-playable character in an update. Luigi is also absent from the open-ended Bowser's Fury campaign in Super Mario 3D World + Bowser's Fury.