List of leaks


 * This article is about Super Smash Bros. leaks which have been proven true; until proven correct, they are to be posted in List of rumors.

A leak is a premature revelation of information about a game, especially without prior permission to release such information. While many measures are taken to prevent leaks, such as enforcing non-disclosure agreements among parties involved in developing the game, games frequently have important information leaked before its formal reveal.

Leaks can either be done intentionally via third-parties for a variety of reasons, such as increasing publicity for a game or for malicious intentions, or unintentionally via oversights in officially released media. Leaks can also be proven fake and created by individuals to receive attention or just to cause commotion, though this article does not cover those instances.

Leaks are not to be confused with rumors, though they are frequently paired together. A rumor by definition is secondhand information that no one can confidently confirm or deny due to a lack of evidence beyond hearsay, though leaked information can come from these rumors if someone can find concrete evidence that a rumor is true.

Due to the lack of a developed infrastructure on the Internet prior to their releases, neither Super Smash Bros. nor Super Smash Bros. Melee had any verifiable leaks. Starting with Super Smash Bros. Brawl, the significantly more developed Internet made them much more common, particularly in pre-release hype. However, a large amount of leaks tend to be invariably sketchy, often with radically different contents from what is actually in the game. The subsequent large amount of rumors makes it very difficult to pinpoint legitimate leaks before their contents are officially confirmed; this is especially a concern with purely textual leaks, as the modes of discourse with these kinds of posts tend to differ very little. In spite of this, a varying number of real leaks can emerge, though they have been historically met with backlash upon their initial posting, often either for being deemed too outlandish to be true or for "parroting" claims made by other posts.

Super Smash Bros. Brawl leaks
As stated prior, the pre-release period of Brawl began a trend in which posts regarding unrevealed content would overwhelm forums and message boards. The few legitimate ones originated from both slipups by those directly involved in Brawl and from people who managed to obtain information about the game. Upon Brawl's release in Japan in late January 2008, leaks could then be cross-checked with the actual game; actual screenshots and videos of the game provided considerable information to players outside of Japan, most of which had not yet been revealed by the DOJO!!.

ChaosZero leak


ChaosZero was a user on GameFAQs that obtained information about Brawl from an unknown source, and posted what he knew on GameFAQs on October 2007. His information leaked the following:


 * ,, and being newcomers.
 * ,, , and returning as playable characters. He also leaked  returning as a transformation of.
 * being cut.
 * The Stage Builder being in the game.
 * The Dragoon being an item, and how it works.
 * returning as a stage.

Prior to his information being proven correct, ChaosZero was treated as a troll, and was largely derided by GameFAQs users and disbelieved in general. However, after the Dragoon item was confirmed, his reputation became more positive, and he earned the nickname "The Dragoon Prophet."

NyaseNya leak
NyaseNya was a user on SmashBoards with an infamous reputation as a troll obsessed with Peach. Despite his reputation however, he obtained legitimate inside information of Brawl, and posted it in a thread on SmashBoards. His information leaked the following:


 * Brawl having 35 playable characters (counting, /, and Zelda/Sheik as a single character each).
 * and being newcomers.
 * Captain Falcon, Ness, and returning as playable characters.
 * Mega Man and Ridley not being playable characters despite being heavily speculated.
 * Brawl being delayed again.
 * Brawl being on a dual-layered disc.

NyaseNya also leaked Sonic and the exact date he would be revealed on. However, like ChaosZero above, he too was treated as a troll giving false information, despite having leaked Sonic's exact reveal date. Even the moderators of SmashBoards treated him as such, with locking the thread and editing his original post to claim he was a liar. After NyaseNya's info was proven correct, Gimpyfish received major backlash for locking and editing NyaseNya's post.

ShadowXOR leak
ShadowXOR was another SmashBoards user who was able to test a build of Brawl firsthand that included yet to be revealed characters. He leaked the following:


 * , Ness, and Captain Falcon returning as playable characters.
 * being a newcomer.

ShadowXOR was treated like the users above, but his information in particular was treated as absolutely false, since almost everyone believed R.O.B. to be a disconfirmed character after being shown as a Subspace enemy.

Lucario/Jigglypuff/Ness leak
On January 18, 2008, a promotional video for Super Smash Bros. Brawl on the official Wii website was posted; this video accidentally leaked hidden characters in the game. Although the video was up for the entire weekend, it was not until Sunday night (Monday in Japan) that a few users noticed something unusual. At one point in the video, a Groudon sticker is highlighted and the faces of, , , and can be seen in the lower right corner, signifying which characters the sticker can be used to power-up in the Subspace Emissary. At another point in the video, a Claus sticker is highlighted, that showed Ness' head alongside Lucas'. This was essentially confirmation that these characters would be playable. Additionally, many fans believed that Mewtwo's absence confirmed that it would not be playable, a belief which ultimately came true. Upon realising their mistake, however, the developers took the video down.

David Hayter leaking Jigglypuff
During an October 2007 interview by UltraNeko with David Hayter, the voice actor of, he was asked which Brawl character he would most like to beat up, to which he replied Jigglypuff, inadvertently leaking it being playable in the game. Users on Neoseeker took notice before UltraNeko's YouTube account went down. Multiple other channels, such as TheUltraPhoenix and proxyXIII, reuploaded the video before either also going down or privatizing the video. A copy remains uploaded to Dailymotion and on Internet Archive.

Super Smash Bros. 4 leaks
Many fake leaks were spread around during the prerelease of SSB4. Several of these fakes would go on to have correct information despite being fake, such as one showing Palutena as a playable character that the creator later admitted was a hoax.

The largest SSB4 leak was the ESRB leak in August 2014, which leaked almost the entirety of the game including all playable characters as well as many stages, modes and trophies with clear screenshot and video footage. The leaked media was subsequently taken down by Nintendo due to copyright claims, followed by the official confirmation of, who was implicated by the leaks. The leak is one of the largest, if not the largest leak, in Smash history.

Leaks for the post-release of a game became possible with the advent of downloadable content.

Gematsu leaks
The Gematsu leaks were a series of major and seemingly credible leaks of Super Smash Bros. 4's playable roster reported by Sal Romano of the gaming site Gematsu, who was being given information from an anonymous tipster via email. Romano would initially leak, , , , , and being in the game shortly before E3 2013, though initially stated as a "prediction" on a NeoGAF forum thread, with him coming out afterward about the source of their information when the former three characters were revealed at E3 2013. Romano would later leak "Pokemon from X/Y",, , Chrom, and Chorus Kids being newcomers shortly before the April 2014 Smash-centered Nintendo Direct. Then shortly before E3 2014, Romano would provide another update, though with the only new information being that " was likely to get cut" and that there would be post-launch paid character DLC.

It would end up proving to correctly leak most of the newcomers, and nearly all of its claims about the roster would prove correct, though two of its claimed newcomers, Chrom and the Chorus Kids, notoriously ended up wrong. However, later evidence shows that both of the wrongly predicted characters were indeed planned to be playable, suggesting that this was a true leak from early planning stages. This is supported by Greninja being listed in the leak as "Pokémon from X/Y", while Sakurai would later confirm he reserved a placeholder slot for a Pokemon from the then-unreleased Pokemon X and Y before settling on Greninja. Additionally, Sakurai would talk about his heavy consideration for Chrom and how he even devised a moveset for him, before ultimately rejecting him in favor of because of his similarity to  and , and datamining would turn up an unused emblem reference for Rhythm Heaven, suggesting that a Rhythm Heaven character, such as the Chorus Kids, was planned for inclusion before being scrapped at some point in development for unknown reasons.

Battlefield Ω leak
In the E3 2013 Developer Direct for SSB4, a clip was shown that depicted and  on the Ω form of, despite the Ω forms having not been officially revealed. However, very few people noticed it and the stage was brushed off as the regular Battlefield, especially as a Battlefield with no platforms appeared in Brawl's E3 reveal trailer despite not appearing in that game. The Ω forms were formally unveiled in the April 2014 Super Smash Bros. Nintendo Direct, with the Ω form of Battlefield being identical to what was seen in the Developer Direct.

Jiggensteins leak
In early May 2014, a GameFAQs user named jiggensteins posted a topic titled "Two New Characters." in which they claimed that and  would be playable characters. They added that both the male and female versions of Robin would be available and that they would fight using magic.

In July 2014 this information was proven to be accurate with the official reveal of Robin and Lucina.

Wario leak
Starting on July 24, 2014, the game was listed on the Nintendo eShop in a list of games featuring Wario before his formal reveal. Three days later, a supposed email from the Australian classification boards, OFLC, had claimed to leak Wario due to his use of flatulence contributing towards the game's rating. Wario's playable appearance in the game was later confirmed by the ESRB leak.

Ninka/Vaanrose leak
Prior to E3 2014, a SmashBoards user by the name of Ninka Kiwi posted in a forum group centered around Smash leaks that he knew a friend who was playtesting Super Smash Bros. 4, though he did not divulge any specific information, other than and  having new palette swaps, with Mario in particular having a new blue palette swap. While Mario having a new blue alt was confirmed true at E3 2014, the leak wasn't discussed much, as Ninka had no real info to dissect and leaking Mario's new blue alt wasn't considered a big prediction, especially as it was overshadowed by the then strong Gematsu leaks.

Later on in July, Ninka came forward with new specific information, which included Lucas, Wolf, the Ice Climbers, and Snake being cut, while, , , in the Koopa Clown Car (with all seven Koopalings as alternate costumes), and the Duck Hunt Dog being new characters. While initially disbelieved and seen as too outlandish, a friend of Ninka who gave him the information, named Shun, contacted a SmashBoards user by the name of Neo Zero, who revealed to Neo that he got the information he revealed to Ninka from his own friend, and revealed that his friend recreated and posted two of the new palettes on imgur, before E3 2014. While this was going on, an apparently completely independent source posted a supposedly leaked newcomer list on 4chan (containing Shulk, Chorus Men, Mewtwo, Ridley, Dixie Kong, Duck Hunt Dog, and Bowser Jr.), containing the two characters unique to the, at the time, completely disbelieved Ninka leak. In addition to this, a person in the Smash community by the tag Vaanrose, known prior for his involvement with the development of Project M, came forward to Neo Zero that he knew a friend who knew someone who worked at Nintendo of America's offices in Redmond, Washington, who disclosed to him that, Bowser Jr., and the Duck Hunt Dog were playable before Robin's reveal. With the screenshot proof of prior exact knowledge of the new palettes, and these new independent sources backing up a completely disbelieved leak, the people involved publicized this additional information legitimizing the leak in a thread on SmashBoards (which is now hidden by the SmashBoards moderation from public view).

At this point the leak was treated with serious legitimacy by the SmashBoards leak group forum, though it remained not well-known or treated with skepticism outside SmashBoards. The emergence of screenshots from the ESRB leak in the following month brought renewed discussion on the leak, with many noting that the details about the character roster lined up identically with Ninka's and Vaanrose's claims, and as such was likely indicative of both leaks being real.

The release of in Japan verified everything described by Ninka and Vaanrose, while the additions made by the 4chan variation of the leak were confirmed false.

ESRB leak
One of the most notable leaks in Super Smash Bros. history took place shortly before the Japanese release of. This leak managed to reveal the entire base roster of characters, including, , , , , , , , , , , and , none of whom were announced at the time. Although initially considered obviously fake by many, the leak gained momentum and popularity after several gameplay videos featuring Shulk, Bowser Jr., and Ganondorf were released and, shortly thereafter, Shulk was officially announced with the same render from the leak. YouTube video footage of these characters was shortly taken down by Nintendo of America, further confirming its legitimacy.

The leak additionally featured several photos of the content sent to ESRB, one notably featuring a trophy of the character Tharja, which does not appear in the final game. Due to her revealing outfit and her trophy's omission from the game, it is believed that the trophy was cut to maintain a lower content rating.

Ganondorf leak
was accidentally shown prior to his reveal in a video posted by Nintendo on August 29th, in which he can be seen offscreen while Pikachu is taunting. This same video was later re-uploaded on September 1st, edited so Ganondorf could no longer be seen offscreen. The original video is now unlisted.

Great Cave Offensive leak
On October 5th, 2014, the official Super Smash Bros Facebook page posted a picture recapping the pictures of the day of the past week. Alongside a picture of the Orbital Gate and the 3DS version's title screen, there was also a picture of Kirby and Pikachu riding in a mine cart in a previously unseen stage. The image was captioned as "Kirby's going for a ride in a mine cart. Well, this situation looks familiar. This stage has some rules that are rare in the Smash Bros. series."

The leak was later confirmed as The Great Cave Offensive, and was revealed officially in the Super Smash Bros. for Wii U 50-Fact Extravaganza.

Amazon leak
About a month prior to 's release in North America, online retailer put up a page to allow for consumers to reserve copies of the game. On the product description for the game, however, information was provided that seemed to suggest a variety of new game modes for the Wii U game: Whether you're creating stages on the GamePad, competing in challenges crafted by Master Hand and Crazy Hand, or outwitting your opponents in a brand new board game mode, there's no doubt that the ultimate Smash Bros. game has arrived.

A mode involving Master Hand and Crazy Hand was later revealed by Sakurai in a Miiverse post, and had previously been implicated by unused content found in the 3DS version. The "board game" and "creating stages" modes, however, had never been previously mentioned on Miiverse or other official material, suggesting that unknown information was still available about the game.

The Super Smash Bros. for Wii U 50-Fact Extravaganza confirmed Special Orders as a mode involving challenges made by Master Hand and Crazy Hand, Smash Tour as a board game mode, and a revamped Stage Builder for the Wii U game, verifying everything implicated in the leak.

Roy and Ryu data
Contained in version of  were new, unused, sound files, seemingly implicated DLC that had yet to be announced. These included, among other things, a victory fanfare "snd_bgm_Z83_F_Roy_3DS" for Roy, which was a duplicate of the existing Fire Emblem victory theme, suggesting he would also return as DLC in the same way Mewtwo and Lucas did, and two files named "snd_bgm_Z81_F_Ryu_3DS" and "snd_bgm_SF01_SF2_Ryu_3DS", both named in reference to Ryu from Capcom's famous series of fighting games; the files contained the victory theme and Ryu's theme, respectively, from . The discovery of these files was first reported by game modder shinyquagsire23 in a reddit thread posted on April 15th, 2015, and was corroborated later that same day by homebrew developer crediar, who confirmed the files were not present in the game's Wii U version, and the staff of The Cutting Room Floor, a wiki that specializes in unused video game content.

More unused files beyond these were present, among them being the remix used for the stage in Super Smash Bros. and Super Smash Bros. Melee and a second Kirby theme, the  theme from Kirby Air Ride. The presence of the Dream Land remix and another forest-themed track suggested that the stage would be future DLC as well. A piece of corroborating evidence for this was also found in following the 1.0.6 update, as Kirby characters would sometimes be fought on  instead of the existing  stage, with Battlefield presumably being used as an error handler for an expected but not present Kirby stage.

Four days later, shinyquagsire23 reported finding more hidden files in the game. An image of the character data showed five unused character slots after Mewtwo named "Mario", presumably as placeholders for future DLC characters. Additionally, the number of inaccessible stage slots had increased from 4 to 14, including slots for Ω forms, meaning there was space for up to 7 more stages and their Ω forms. The existence of these slots suggested there were more stages planned for DLC beyond Dream Land.

Despite the files being present in the update for a long time, it was not until June 13th, 2015 that they were confirmed to represent real DLC content. On that date, Random Talking Bush, an administrator of and contributor to the site The VG Resource, revealed that he had successfully downloaded the 1.0.8 update of the Japanese version of SSB4 from Nintendo's servers before it was set to release; he then proceeded to datamine its contents and post links to them on his twitter account, showing the characters' ending videos, official art, costumes, and trophies, along with the rest of the planned DLC. Later during that day, crediar was able to test out Lucas, Ryu and Roy before their release on his Twitch stream by editing the files to run over Mario.

Parts of the stream were uploaded to YouTube, but have since been taken down by Nintendo of America on copyright claims, similar to how they took videos down after the ESRB leak. All videos on major YouTube channels talking about the leak were also taken down, including those on GameXplain and the late 's Etika World Network.

Roy, Ryu, Dream Land (64), and all other elements implicated as DLC were formally announced and released on June 14th, 2015. Notably, Ryu's victory theme was replaced with a remix as opposed to the direct rip from Street Fighter II present in the 1.0.6 data; also, the Forest Stage track that was found in the 3DS version would end up only being used on Dream Land (64) on the Wii U version, as the 3DS version ended up using  as its alternate track instead. Furthermore, exactly 7 other stages aside from Dream Land were added to the 3DS version of the game via DLC and updates, including, which came free after version , and Suzaku Castle, which became available with the same update that Dream Land did. Lucas, Roy, and Ryu filled up three of the five placeholder slots upon their release; sometime later, a sixth placeholder slot was added, which came in line with three more DLC characters being released and filling in all of the placeholders.

Super Smash Bros. Ultimate leaks
Several rumors regarding a Smash title for the then-unnamed Nintendo Switch pervaded in the time preceding the announcement of Super Smash Bros. Ultimate, many of them centering on the debate if the system would, assuming a Smash title was going to release, receive a port of an existing title or be a completely new one. Following the game's announcement in 2018 and the release of more information in the months that followed, nearly all of them were proven false. Afterwards, however, real leaks began to emerge, ranging from minor ones, such as the premature confirmation by a former employee that Bandai Namco would return to develop the game, to much larger ones, such as the dispersion of an illegal copy of the full game two weeks prior to release, which in itself leaked several details regarding the game.

Vergeben leaks
On May 16th, 2018, a user known as Vergeben posted a thread on GameFAQs, claiming he had a reliable source with information on the character roster of the then teased but still unrevealed Super Smash Bros. Ultimate. He would later follow up his statements on GameFAQs and reddit with multiple others later on, most of which had correct information.

The following are the claims made by Vergeben that would be later proven true:
 * ,, , , and would appear as newcomers, the latter as an Echo Fighter of.
 * All characters from Super Smash Bros. 4 would return, as well as and the.
 * Over half a dozen newcomers would be included (specifically eleven in the base game).
 * Decidueye, Lycanroc, Mimikyu, and Isaac would not be playable, the lattermost instead returning as an Assist Trophy.
 * , either Luminary or Erdrick (Luminary and Erdrick both being present under the banner of ), and would be part of the Fighters Pass Vol. 1.
 * would appear as the fourth character in the Fighters Pass Vol. 1.
 * The final fighter in Fighters Pass Vol. 1 would not be from Ubisoft, Bandai Namco,, , , Capcom, Sega, Konami, Arc System Works, Spike Chunsoft, Marvelous, , , Bethesda Softworks, Koei Tecmo, , , , Microsoft, Square Enix, or.
 * The Mii Fighter costumes releasing with would be Altair, Cuphead, a Rabbid hat, and two Mega Man costumes.
 * representation would come in some form. would appear as the second character in the Fighters Pass Vol. 2.
 * Nintendo and would collaborate on Smash in some way, in this case with Spirits based off of the Koei Tecmo developed .

7-11 poster leaks
A notable recurrence during the post-release of Super Smash Bros. Ultimate were posters regarding upcoming and recent Nintendo content being placed up at 7-11 stores in Japan and being taken down at specific dates. These posters, which also detailed information on the Fighters Passes, had many fans correctly guess that the characters would be released before the posters were removed:
 * On July 24th, 2019, former Source Gaming member PushDustIn posted a photo to Twitter depicting one of the posters in question, which included information on both Fire Emblem: Three Houses and the in Super Smash Bros. Ultimate. While it only stated that the Hero would release in the summer, the poster also said it would be taken down on August 4th. Hero was released on July 30th, five days before the poster was taken down.
 * On September 1st, 2019, PushDustIn posted another photo with a 7-11 poster, this time including information on both the then upcoming remake of The Legend of Zelda: Link's Awakening and in Super Smash Bros. Ultimate. The poster was to be taken down on September 15th, and Banjo & Kazooie would indeed release on September 4th, eleven days before the poster was removed (though interestingly the Link's Awakening remake released five days after the poster was removed instead of before).
 * On September 20th, 2020, posted a photo on Twitter depicting yet another poster at a 7-11. This poster included information on the second Fighters Pass and was set to be taken down on October 4th. On September 30th, it was announced that the contents of Challenger Pack 7 would be revealed on October 1st, thereby continuing the trend of the poster leaks. This character was then revealed to be.

PracticalBrush12 leaks
On January 16th, 2020, 10 minutes prior to the airing of the Smash reveal, a Reddit user named PracticalBrush12 created a post on /r/SmashBros revealing what would be announced. They revealed that Byleth from , both male and female versions, would be the next downloadable character. They also revealed that Byleth would use alongside the, , and. Additionally, a Cuphead costume for was also revealed by the leaker. The leaker had previously properly leaked ', ', ' (including its DLC), and '. When the reveal aired, all of the information leaked by PracticalBrush12 was proven to be correct.

On October 1st, 2020, roughly 30 minutes prior to the airing of the Smash reveal, PracticalBrush12 would again create a post on Reddit explaining that Steve from  would be revealed as a playable character alongside Alex, Zombie, and Enderman. The leaker also described Steve's Final Smash as him utilizing a piston. In between this Smash leak and the last, PracticalBrush12 had also properly leaked . When the reveal aired, PracticalBrush12 was correct once again.

Battlefield and E3 2018 Booth leak
On April 24th, 2018, a YouTuber by the name of "Master0fHyrule" claimed on Twitter that a source had told him that Bayonetta, Duck Hunt, and Shulk would return as playable characters for the upcoming game. On the same day, he claimed to have seen the new version of Battlefield and uploaded an image of which he described as "a small piece of it from the Top-Down view".

A day later, a YouTube user by the name of "GU KingofHeart" published a video in which he claimed that he received information about display items being featured at the Super Smash Bros. section of Nintendo's then-upcoming E3 2018 booth. He claimed that his source was the same source that leaked that Nintendo's E3 2017 booth would have a New Donk City-themed area, which turned out to be true. He revealed the following:


 * Bayonetta's handguns and boots
 * Captain Falcon's helmet
 * Fox's Blaster
 * Link's Master Sword
 * Marth's Falchion
 * Shulk's Monado
 * A Golden Hammer
 * A from 

These supposed items hinted the return of Bayonetta, Captain Falcon, Fox, Link, Marth, and Shulk as playable characters, the return of the Golden Hammer as an item, and the inclusion of greater Splatoon representation. It also supported Master0fHyrule's claims of Bayonetta and Shulk returning.

In addition to the display items, GU KingofHeart also uploaded an image of what he claimed was the center of the new Battlefield. The image lined up with Master0fHyrule's previous image.

All of the uploaded videos and tweets were deleted soon after they were posted. Discussion of the two leaks mostly remained within ResetEra and SmashBoards. On June 12th, 2018, the day of Nintendo's E3 2018 event, a new trailer for the previously untitled Super Smash Bros. Ultimate was demonstrated. In the trailer, the new was revealed and officially confirmed both Master0fHyrule and GU KingofHearts' leaked images as real. The trailer also confirmed that every previous fighter would return, confirming the leaked characters in the process. At Nintendo's booth, all of the display items leaked by GU KingofHearts' source were confirmed to be real.

Rendering engine leak
On May 9th, 2018, a former software engineer and graphics programmer for Bandai Namco named Tiago Sonobe stated on Twitter that after his August 2016 departure from the company, work had begun on a new Super Smash Bros. game using the in-house rendering engine which Sonobe had developed. Following the spread of the tweet, Sonobe's Twitter account was entirely deleted.

E3 2018 4chan leak
On June 11th, 2018, one day before the Nintendo Direct at E3, a 4chan user leaked the following information about the upcoming Smash game:


 * All previous characters will return.
 * will be heavily redesigned.
 * and are newcomers.
 * Old stages are returning.
 * Bomberman will be an Assist Trophy.
 * Its title is Super Smash Bros. Ultimate.
 * Its release date is December 7th, 2018.
 * Clone characters receive an icon next to their name (later revealed to be indicating Echo Fighters).

As had been the case for many Brawl leaks, the leaker was considered a troll and mocked for their claims. During the Direct, his information was confirmed mainly factual.

The leak made a few notable errors, such as claiming that was an Echo Fighter, that 's Final Smash would be a Squid Sisters concert which would cause the screen to zoom in, and that all stages would have a Final Destination and Ω form (which are the same thing). In reality, Lucas is not classified as an Echo Fighter, the Squid Sisters were revealed to be an Assist Trophy with the same function as described in the leak while Inkling's Final Smash was confirmed to be Killer Wail, and it was confirmed that stages would have both a Ω form and a Battlefield form. However, given that the rest of the information was correct, as well as the fact that the same user correctly predicted the title and gameplay style of  Super Mario Party, another game featured in E3 2018, it is likely these errors were made from misinterpretation or assumption rather than being indicative of a hoax.

Castlevania music leak
On the night of August 7th, 2018, close to the airing of the Super Smash Bros. Ultimate-centered Nintendo Direct the following morning, the YouTube video for the Galaga Medley on Nintendo's Super Smash Bros. channel that was previously confirmed the week prior was renamed to "Bloody Tears / Monster Dance", both of which are tracks from . It was later properly renamed back to "Galaga Medley".

Following the Direct, which announced and  as new playable characters from the  series, "Bloody Tears / Monster Dance" was properly uploaded to the website. Due to this incident, all the music previews were renamed to numbers, with each new upload incrementing by one.

Loz18 leaks
On June 11th, 2018, GameFAQs user Loz18 made a thread about Ultimate before its E3 reveal. In the first post, he stated the following:


 * All previous characters will return.
 * Inkling's ability to recharge ink and their special moves being Super Jump, Splattershot (albeit referred as "Tentatek Attack"), and Splat Bomb (albeit referred as "Bomb Attack").
 * Ganondorf's outfit is based off of Ocarina of Time and his up smash changed from a kick to a sword attack.
 * Zelda's outfit is based off A Link Between Worlds.
 * Link's moveset is almost unchanged, but the s from Twilight Princess are replaced with Remote Bombs from Breath of the Wild.

Two days after the E3 reveal confirmed all of this information to be correct, Loz18 made another thread about a Nintendo Direct in August stating:


 * The Nintendo Direct will come around August.
 * Info will be shown from the title screen to the menu options.
 * Three modes will be shown besides All-Star Mode.
 * Tournament mode is returning.
 * The new mode will be revealed and it will be the primary way to unlock characters.

About a week before the August Direct, he made some more posts mentioning a cutscene with a heroes vs. villains theme, but not part of a story mode.

Several menu screens, three new modes, Tournament Mode, and the heroes vs. villain cutscene (at the start of 's reveal trailer), and the title screen were indeed revealed. All-Star Mode, and the mode to unlock characters were not announced during the August Direct, though come the game's release there would be a new fighter unlocking mode in the form of Challenger's Approach, and the player is additionally able to unlock characters via World of Light (in a similar vein to the Subspace Emissary).

Spirits mode decensoring
During the main menu preview in the August 8th, 2018 Ultimate Direct, a then-unannounced mode is featured but censored by a pixelated blur filter. The filter is implemented in such a way that the blurring is applied incorrectly on its bottommost section. This oversight causes parts of the mode's name and icon to be briefly visible as Smash mode is selected and deselected.

This was first documented by Twitter user Lattie9001 (known as Noctulescent at the time) in a Twitter thread made shortly after the Direct. The first tweet shows two frames that reveal the mode's name as "Spirits". Another tweet shows the same frames during the Japanese version of the Direct, revealing the name (Spirits). A later tweet claimed that, when observed via the oversight, the icon resembles a, an item associated with spirits, drawing a connection to the name. All this was later corroborated by multiple Twitter users following Lattie's explanations on how to see behind the blur filter using the frame by frame feature on Youtube.

In the November 1st, 2018 Ultimate Direct, the then-unannounced mode was revealed as "", and the symbol was very similar to the unblurred edits.

CoroCoro stages leak
The September 2018 issue of CoroCoro, a Japanese magazine, featured information about Ultimate: though most of it was a retread of what had been in the August 2018 Smash Direct, the magazine stated that the game would have 108 total stages. This was contrary to the aforementioned Direct, which instead stated that the game would feature 103 stages. While this could be assumed as a printing error, many users noticed how this number perfectly matched with the shown in the Direct, with room for six more spots.

The October issue of CoroCoro dropped the stage count back to 103. Five stages were released as DLC for the first Fighters Pass, bringing the stage count to 108, and, as the second Fighters Pass had not been in its planning stages until after the game's launch, CoroCoro had incidentally leaked the amount of initially planned DLC stages.

No new Codec Conversations
On September 8th, 2018 in Fan Expo Boston 2018, a fan asked David Hayter (the English voice actor for ) about Ultimate, and Hayter replied that more Codec Conversations hadn't been recorded yet. This led some fans to believe that the Codec Conversations would not be in the game at all. Some that played the demo cited the removal of the Star Fox Smash Taunt in Lylat Cruise, though others guessed that it simply was disabled for the demo. As 's Star KO voice clip was completely new, some believed that both Palutena's Guidance and the Codecs could have been rerecorded. Others noted that Hayter was likely bound to a non-disclosure agreement and thus was forbidden from discussing anything not permitted by his contract; however, Hayter himself brought up the topic of Codec Conversations without being asked specifically about it, even after openly acknowledging that he probably was not supposed to say anything, which makes it unlikely that he was trying to obfuscate the truth. Hayter also expressed dismay on not being able to record new lines for Ultimate codecs. Additionally,, Roy Campbell's Japanese voice actor, passed away in 2012, and future Metal Gear titles do not feature the character out of respect for Aono. This made it more likely that no new Codec Conversations would be recorded.

It was later revealed from early copies of Ultimate that the Codec Conversations from Brawl return, but that there are no unique Codec Conversations for characters that weren't playable in Brawl. This is in line with Hayter's previous statements that he had not recorded any new voice lines for the game. However, Palutena's Guidance did receive new voice lines in Ultimate for characters who were absent in Smash 4's base roster, (who is DLC), and redesigned characters.

Noatesty leaks
On September 14th, 2018, Reddit user Noatesty made several posts where they claimed to be a playtester for Ultimate and shared several details about then unrevealed content.

In their first post, Noatesty claimed that and  would be the final playable characters in the base game, and that Flies & Hand from Mario Paint would be an Assist Trophy. They also shortly described Spirits, comparing them to Brawl's stickers, detailed Fishing Rod's functionality as a tether recovery, and claimed that the game would receive a day one patch with new modes, and that the internal codename of the game was "Cross2".

In their second post, Noatesty further described 's moveset, claiming that her forward, back, up and down aerials, which had not been shown at the time, were similar, if not identical, to their respective counterparts in 's moveset.

In their third and final post, Noatesty claimed that a was going to be the first downloadable character, and said that it did not have its iconic fireball attack anywhere in its moveset. According to them, it was only accessible via a debug menu in the test build they played. They also described Incineroar's moveset, claiming that it would mostly consist of wrestling moves; its side special appeared to not be based on any existing move, but instead had it summon ropes and launch opponents against them. It also had a purple alternate costume that they claimed resembled character Big the Cat.

On November 1st, 2018, Ken, Incineroar and Piranha Plant were revealed as playable characters, the lattermost as DLC, while Flies & Hand was revealed as an Assist Trophy; it would also reveal that the mysterious mode teased in the previous direct was called Spirits and featured collectibles similar to stickers. Later that day, the Nintendo Treehouse stream also validated Noatesty's claims about Isabelle's and Incineroar's movesets. On November 28th, 2018, it was announced that the game would receive a day one update, although the contents of the update were not disclosed in detail. After the update was released, it was revealed that downloading it would enable online modes and add a Hard difficulty setting to World of Light; it is unclear if these are the modes that Noatesty was referring to. Datamining the game also revealed that the internal project name was indeed "Cross2".

Ken leak
On September 21st, 2018, a 4chan user posted a cropped screenshot of Ken Masters from the series on Moray Towers. Later, the user uploaded the full screenshot to the same thread, showing off Pichu, Ivysaur, and Pac-Man taunting alongside Ken on the Moray Towers stage. Allegedly, Ken's model is not a port of another game, but a new model altogether.

Some users pointed out that the portrait of Pichu had its ear cut off, which actually matched up with the E3 reveal trailer. Ken was partially standing on a metal surface where his shadow does not appear under his foot: SmashBoards user DJ3DS recreated the shot in the demo build with Pikachu and Ryu instead of Pichu and Ken; the shadow is missing from the metal surface in the demo build, meaning that the error in the leak does in fact exist in the game.

was announced on the November 1st Super Smash Bros. Ultimate Direct, with his model and render matching with the one in the photo.

Piranha Plant 4chan leak
On September 24th, 2018, a 4chan user made a thread claiming that the final three newcomers in Ultimate would be Incineroar, Ken (as an Echo Fighter based on Ryu), and Piranha Plant. They also elaborated on Piranha Plant's playstyle, saying that it would be in a vehicle of some sort in a similar vein to Bowser Jr.

On November 1st, 2018,, , and were confirmed to be playable fighters in the final pre-launch Super Smash Bros. Ultimate Direct. However, while the 4chan user's assertion that Ken would be a Ryu Echo Fighter was correct, Piranha Plant did not fight in a vehicle as the user claimed, instead being in a pot or Warp Pipe (depending on the costume selected) and walking on its roots from under the pot, though this was more likely a misconception than deliberately false information, similar to the small errors in the E3 2018 leak.

Completed game leak
Two weeks prior to the release of Ultimate, a leaked copy of the game was distributed across the internet, in part due to an accidental release in Mexico. Nintendo took steps to issue copyright strikes on YouTube videos using data mined content, while fans worked to isolate spoilers, particularly the World of Light story mode, from those that had played the leaked version. As the entire roster and selection of stages were all revealed before the leaks, very little info shown off from those were not already known. However, the following information that was previously unknown was shown off:
 * The existence of Dharkon and The Dark Realm were leaked, as well as the appearances of Crazy Hand, Marx and Ganon as bosses of The Dark Realm (along with the previously revealed Dracula).
 * A majority of the music tracks present in Ultimate were leaked, and several YouTube channels that had uploaded the music were taken down (such as Crunchii, a channel that Nintendo had previously trusted to release a short loop of the Menu theme from the E3 2018 demo).
 * All 1297 of the base game spirits were leaked as well, with Camilla's and Mythra's spirits being shown for the first time with censored artwork.
 * The functionality of Squad Strike was shown off after months of speculation about what it would be (despite the mode being revealed during a Nintendo Direct, it had been unclear how the mode worked).
 * The process and order for unlocking fighters was discovered and demonstrated.
 * The character select screen with Echo Fighters stacked was first shown off in the early release leaks, indirectly showing off that it would also stack s. It was also shown that the stacked option will not affect single player modes or Squad Strike.
 * The exact parameters of every character's attributes and movesets were made public, including a beta version of 's, showing it to formerly be the slowest character in the game.

Milk-BOSATU leak
On October 11th, 2018, Twitter user Milk-BOSATU (currently named Team NepDon) made a tweet that claimed that the Hero from Dragon Quest series is a playable character with no female alternate costumes alongside with VR content for the Switch coming. VR content for the Switch was later revealed as Nintendo Labo VR Kit March 2019 and the Hero was later confirmed to be a DLC fighter in the Fighters Pass Vol. 1 at E3 2019.

DLC datamines
On November 28th 2018, a technical data Discord server uncovered Ultimate's character parameters table (the list of values such as walk speed and weight) and began decoding it in preparation for the game's release (Ultimate uses s to store strings, so they are not immediately evident and require knowledge and patience to crack). It was found that the first column in the table stored each character's internal development name. It quickly followed that, not only were 's values already included in the table under "packun" (its Japanese name being Packun Flower), but there was one further slot named "jack". After the 1.1.0 update was made available on December 5th, a second unknown character's attributes were found to have been added, called "brave". Out of respect for players and the game's development team, these discoveries were kept secret.

On January 3rd 2019, the existence of "jack" and "brave" began to quickly spread from an unknown source. With having been revealed, it was assumed that he was "jack" (as "jack" and "joker" are both types of s). "brave", however, was less clear. The most common speculation was a Hero from ; the default class in most games of the series is (Yūsha), which means "Hero" and directly translates to "brave" in English. The parameters of "brave" revealed that their weight is between and /, their running speed is between  and, and they did not have a neutral infinite, wall jump, or crawl. As confirmed upon the release of version, this data does indeed refer to all four es present in the game.

The data for "jack" and "brave" was removed from the game data in version, along with the release of Piranha Plant.

Later, text strings were discovered in the game data that referred to upcoming DLC. Due to a technical oversight in a particular file format used for Ultimate's stage data, unrelated development text leaked into stage data files. The string "Jack_Menentoes_" was discovered, confirming Joker's stage as Mementos from Persona 5.

Another discovery seemed to imply that one or more of Joker's alternate costumes was an alternate character who has a ponytail hairstyle. At the time this was speculated to be recently revealed and unnamed Sumire Yoshizawa from Persona 5 Royal. However, retrospectively, based on similar datamined strings from the dump, it seems to have been two separate strings for different files combined into one. "Jack6_C06_v01_070925.mb" referring to a .mb (Maya Binary) project file for Joker's Shujin Academy alternate costume (referred to as C06 internally) and "Jane1_pony_hairSystemShape2.mchp" referring to a .mchp file (a Maya file format related to hair ) for Ann Takamaki's twin ponytails seen in the Mementos stage. Similar to the misspelling of "Menentoes" internally, Ann's name (spelled as Anne in Japanese) was listed as "ane" with a "J" prefix to signify connection to Joker internally, once again similarly to the Mementoes stage strings, which carried a "Jack" prefix.

Following the leak, the next update to the game,, removed all of the leaked data and patched the oversight that caused it.

Extra game modes datamine
On March 8, 2019, Ultimate's files were datamined, revealing two files named "howtoplay_stage_builder.html" and "howtoplay_homerun.html". The intended purpose of these files is unknown, but it led fans to speculate that Stage Builder and Home-Run Contest would return to Ultimate in a future update, with "howtoplay" signifying that the files are for a menu that pops up when the player first selects the modes.

A leak in an advert by Nintendo would later reveal that a Stage Builder was in fact being developed, and it was officially revealed on April 16, set to be released the following day. Home-Run Contest would later be confirmed and released on September 4th with the version 5.0.0 update.

Joker render leak
On March 31, 2019, Best Buy published a weekly ad about the Fighters Pass Vol. 1 featuring a render of. Although the ad was replaced the next day with a fast store pickup ad, the render garnered speculation that Joker's release date and/or gameplay reveal would be at or around the first week of April.

2 weeks later on April 16, Nintendo of Europe's databases added the image of the full render of Joker. That same date, Nintendo released information through a video that Joker would be released the following day, April 17, and fully confirmed the legitimacy of Joker's render.

Stage Builder leak
On April 9th, 2019, Nintendo uploaded an ad related to Ultimate; fans quickly noticed that a mere one second in, a "Stage Builder" option could be seen under "Games and More" on the menu. This seemed to imply that one of the new modes to be added in the 3.0.0 update was going to be a Stage Builder mode, seen previously in Brawl and Smash 4, but notably absent in Ultimate. This was further supported by the Nintendo Direct aired on February 13th, 2019, which showcased a blurred out image of what was believed to be Stage Builder. Due to the video not being covered up or deleted like the one that revealed Ganondorf, some have speculated that this was in fact not a leak but an intentional marketing ploy.

Stage Builder would later be officially confirmed in a special presentation video about version 3.0.0 on April 16, 2019.

Banjo & Kazooie leak
On June 4th, 2019, ResetEra admin shinobi602 made a post a week before E3 2019, stating: 'Been a while since we saw Banjo in anything. Hope we're in for a smashing good time.' The phrase "have a smashing good time" is notable in that ResetEra admins had used the phrase to tease upcoming Super Smash Bros. content in the past. ResetEra has strict policies about users posting rumors, and as shinobi602 was an admin, along with his perfect track record regarding leaks, this lead many people to believe that shinobi602 was teasing an upcoming reveal at the E3 2019 Nintendo Direct. This leak was eventually supported when were revealed as a part of the Fighter's Pass for Super Smash Bros. Ultimate at the E3 2019 Nintendo Direct on June 11th, 2019.

Hero July release date leak
On July 16th, 2019, Nintendo uploaded a video under the name "Fan-Favorites & Newest Releases - July" which showed brief clips of Marvel Ultimate Alliance 3: The Black Order and Fire Emblem: Three Houses, two upcoming games slated to launch in July, as well as Fortnite, the ninth season of which was currently ongoing, and in Super Smash Bros. Ultimate. This led many to believe that Hero would launch sometime in July. Nintendo later renamed the video to "Fan-Favorites & Newest Releases - Summer".

On July 30th, Hero was confirmed to release on that day.

Dragon Quest spirit board leak
On July 26th, 2019, several spirit images from were discovered to be uploaded by Nintendo onto the Smash World spirit database, which included: Sometime later, Nintendo took down the images. All of the spirits were later confirmed to be in the game, as a part of the Dragon Quest DLC Spirit Board.
 * Slime
 * King Slime
 * Dracky
 * Golem
 * Cetacea
 * Great Sabrecub
 * Great Sabrecat
 * The group of party members from .

Nintendo of Europe 4.0.0 release date leak
On July 29th, 2019, Nintendo of Europe posted a tweet containing a release date for the then-upcoming 4.0.0 update, being July 31st. The tweet was then taken down, and replaced with a tweet which instead stated "within 7 days".

The following day, Hero was confirmed to release on July 30th in North America (July 31st in Europe due to time zones), the day the presentation for Hero aired.

Nintendo of Europe site SNK fighter leak
On September 1st, 2019, a page for the 4th Challenger Pack in the Fighters Pass was created on Nintendo of Europe's website. Within the page, people noticed a mention of a copyright belonging to SNK Corporation, leading to speculation that the next fighter would be from SNK, with Terry Bogard from being the most prominent guess. People also speculated that the copyright was borrowed from the DLC pages for  due to having an identical filesize and an incorrect date. However, as the listing lined up perfectly with the other Challenger Pack listings and Nintendo pulled down the page soon after its posting, the SNK copyright was strongly suggested to be a legitimate mistake. Three days later, an SNK fighter was indeed revealed, specifically Terry as speculated.

Spirit Board Event SNK copyright
On October 30th, 2019, the notification for the Spirit Board Event Smash by the Sword went live. The event ran between November 1st to 4th. Located at the bottom of the notification is the copyright for the SNK Corporation, which was newly added. This led to rumors that 's release date would be near the beginning of November. This speculation was eventually proven correct with Terry's release on November 6th.

Sora/Disney Music Leak
On July 30th, 2021, an anonymous 4chan user posted in a thread that Sora from would be revealed on October 5th as the last playable character for Super Smash Bros. Ultimate. Later that same day, another anonymous user in a different thread claimed to be a Disney Music employee, and mentioned that Nintendo had recently asked for permission to use Disney-owned music in a digital event that was supposedly scheduled for October 5th, drawing the conclusion that Sora would be the last DLC fighter. While they were largely overlooked prior, the posts gained widespread attention after the September 2021 Nintendo Direct, in which the last Ultimate fighter was announced to be revealed on the date predicted by the post. Sora went on to be revealed in the aforementioned presentation; notably, Sora's reveal featured music not present in his Challenge Pack, which would ostensibly require additional licensing agreements, as the second post suggested.

Sora amiibo leak
Despite amiibo data existing for, , , and prior to 's reveal, it was left unknown whether Sora was to get an amiibo for two years. On July 4, 2023, Twitter user ARTSWIFT explained that Sora amiibo will be released in the near future. Since the last presentation for Super Smash Bros. Ultimate,  on October 5, 2021, there had been no official confirmation of this happening, nor has there been support of said amiibo in the latest update, version on December 1st, 2021. In the following weeks, new rumors were reported by numerous news outlets where restocks of amiibo will happen after August 2023 and will be released in waves.

During the Nintendo Direct of September 14, 2023, Sora's amiibo was announced with a pending release date set for 2024, confirming the leak from ARTSWIFT in July 2023. Later, the amiibo got a release date set for February 16, 2024.