Unlockable character

An unlockable character (also referred to as a secret character or hidden character, and in-game as challengers, or newcomers in the N64 game's Backup Clear menu) is one that is not available at the start of the game (unlike a starter character), but instead must be received in-game (unlike downloadable characters) through other means.

Unique criteria must be met in order to unlock each character, as outlined below. Once such criteria are met, the challenger will appear the next time the player returns to the menu. If the player wins the subsequent battle, a message will appear congratulating them for unlocking the new fighter.

In Super Smash Bros., the character select screen displayed placeholders for not yet unlocked characters. This was changed in Super Smash Bros. Melee, where the clones didn't have placeholders prior to unlocking, with their portraits simply appearing afterward. The placeholder slots were completely removed from Super Smash Bros. Brawl onward.

Whenever a character is unlocked, a screen telling the player that the character is now playable will be displayed:
 * In Super Smash Bros., the screen says that "you can now use" the character, featuring a unique title for each of them.
 * In Super Smash Bros. Melee, the screen displays a sentence that is unique to each character and features the unlocking timestamp.
 * In Super Smash Bros. Brawl, the screen says that the character, with their unique title too, "has joined the brawl", and also features a portrait of the character.
 * In Super Smash Bros. 4 and Super Smash Bros. Ultimate, the screen says that the character "joins the battle!" while playing  from Melee, before archiving their corresponding milestones. This also applies to downloadable content characters once they are downloaded, or when the game is booted after a character's release date in case of being purchased via Fighters Pass in the latter game.

"Challenger Approaching!" screen
The "Challenger Approaching!" (, A Challenger has Appeared!) screen is a message that will be displayed after the player has met a criteria required to unlock any of the available characters. Every game has its unique screen.

Super Smash Bros. had a silhouette of the character merely displayed in a blue box in front of a black background, with an exclamation point in a red circle on the top of the screen, and the phrase "Challenger Approaching" next to it. The screen uses similar music to the 1P-Game's intro, with the only difference being the absence of drums for the "challenger approaching" tune. As a result, this is the only game where the challengers' silhouettes are animated, showing them in their fighting stances while rotating (like in the character select screen), rather than just shadowed versions of their official illustrations.

Super Smash Bros. Melee added the phrase "A new foe has appeared!," and also had a silhouette of the approaching challenger. The poses for the challengers were silhouettes of their renders when selected on the character select screen (some, however, like Luigi and Ganondorf's, were their renders from inside the boxes). The game also added animations to the screens, with an undulating matrix effect in the background, while the exclamation point, text and silhouette would be eased in. Original music was also provided solely for the screen, which took the sound of a slow, ominous siren.

Super Smash Bros. Brawl returned to the plain black background (there would be a silhouette of an unlockable character the player would face); but this would only occur if the Subspace Emissary method was not used. Also, Brawl removed the word "Warning" and the circle explanation point logo from the challenger approaching screen. It still had animations that would ease in, and when the player pressed any button, the images would fade to black, while the "Challenger Approaching!" text would scatter all over the screen; the siren is also considerably faster and more panicky in its sound than how it sounds in Melee.

Super Smash Bros. 4 reused Brawl's warning siren, but there are some differences in both versions. The 3DS version added in considerably more colors, including hues of green, black, and violet; the screen also says "A challenger approaches!" instead of its previous quotations. The Wii U version uses a font style similar to the ones in the newcomer trailers, and the background contains a picture of a supernova; the text is nonetheless reused from past games. The unlockable character in both versions of Super 4 on the screen is still a silhouette that the player would face (just like in the previous three installments).

As in Smash 4, the warning siren from Brawl is used in Super Smash Bros. Ultimate. This time there is a dark pink background with a white/pink light shining behind the silhouette of the unlockable character. The text about unlocking characters remains the same from prior games.

After the "Challenger Approaching!" screen, the unlockable character will then be fought in an ordinary one stock match with no time limit, on a predetermined stage with predetermined music. The AI difficulty of the duel depends on the game, usually at low difficulty for the first fighter, then it gradually increases with every fighter unlocked, however, it is reversed in Melee, and always high in the Wii U version of Smash 4. The player uses the last character played as, including the last used costume. In the case of multiplayer battles, in the first three Smash games, the player who won the match will fight the challenger; if a CPU wins the match, the challenger will not appear. Super Smash Bros. 4 changed this formula such that if a CPU wins the match, then the human-controlled player with the highest rank will battle the challenger.

By defeating the opponent, the character becomes playable. If the player fails, however, they will not unlock the character, but in the next battle they win, they are guaranteed to meet with the challenger again.

The "Challenger Approaching!" screen has become somewhat of a meme in the Smash community. Many digitally manipulated versions of these screens have appeared, often featuring characters who do not appear in the games, mostly using artwork of the character from another game instead of original artwork (which gives away its falseness). The screens became so popular that they were featured as part of the DOJO!!; in earlier updates, whenever a new character was introduced, a banner that said "Warning! Challenger Approaching!" would appear above the entry.

Fighters
Melee introduces a alternate method for unlocking each fighter, by completing a certain number of VS matches, in intervals of 100.

Super Smash Bros. Brawl
In Super Smash Bros. Brawl, the first game to feature third-party characters, both third-party characters ( and ) are unlockable characters.

The Subspace Emissary
The Subspace Emissary features its own storyline and character selection screen, with characters met and joining the mode's roster as part of the story. (For example, is a starter character, but he cannot be played as in the SSE until he is 'unlocked' in the SSE.) Characters can also leave The Subspace Emissary's roster as part of the story, and cannot be played as until they are met again.

Unlocking any non-starter character in The Subspace Emissary will also unlock them for play in other modes. This occurs instantly, without requiring a "Challenger Approaching" battle. Thus the Subspace Emissary serves as a third method for unlocking characters, in addition to the challenges and versus match methods. All characters can be met in The Subspace Emissary; however, Toon Link, Wolf, and Jigglypuff are only unlockable after the main story is completed by finding a secret door while replaying certain levels.

Below is a chart of when each fighter is unlocked, removed, or changes or combines teams; stages with none of these are omitted.

The Subspace Emissary consists of 31 different stages. As some stages share the same name, the earlier stage is denoted with an I while the later-appearing stage is followed by a II.

Fighters
The inclusion of and Wendy O. Koopa (as one of 's s) as unlockable characters makes them the first female characters to be unlockable. After every tenth VS. match, the player gets to challenge an unlockable character, starting with and finishing with  when 120 matches are played.

In addition to the characters below, s are not shown on the character select screen until the player has created at least one. However, since the ability to create Mii Fighters is granted from the beginning, the characters cannot truly be called unlockable.

Despite having a stage of the same name added into the game in the  update, they will be fought on  for their unlocking battle regardless of which version of the game is being played.

Fighters
Unlike, Ness, Jigglypuff, Ganondorf and Bowser Jr. are starter characters. Like the 3DS version, a character is unlocked for every ten versus matches played starting with Falco. Two exceptions to this are and, which they need 20 more versus matches than  and Mr. Game & Watch, respectively. Unlike the previous three installments (Melee, Brawl, and the 3DS version), no universe stages are used for challenger approaching battles. Instead, all unlockable characters use a stage from their respective universe except for R.O.B., in which he uses the Wrecking Crew stage due to him not having a stage from his own universe.

In addition to the characters below, s are not shown on the character select screen until the player has created at least one. However, since the ability to create Mii Fighters is granted from the beginning and there is no Challenger Approaching fight, the character cannot truly be called unlockable.

Super Smash Bros. Ultimate
The starting roster in Super Smash Bros. Ultimate comprises the eight starter characters from the original Super Smash Bros. game, with all other fighters being unlockable or downloadable. With the vast majority of the roster being unlockable, unlocking characters is advertised as a core feature of the game; no characters are left "secret" like in previous games, and character unlocks are designed to occur at a more streamlined and consistent pace than in previous games.

Unlockable characters no longer have unique criteria to unlock them. Instead, Challenger Approaching fights take place after completing with any character, and as timed encounters.

As in Smash 4, s can be unlocked by creating a custom Mii Fighter of that type, and do not have a standard Challenger Approaching match.

The player may also unlock characters by awakening them in the World of Light.

When the player completes Classic Mode with a given character, a new character will challenge the player to a Challenger Approaching duel. All of the eight starter characters have their own character unlock trees, each with eight characters to unlock, except for Pikachu, who has seven. The challenger is determined by the first player character, and will be the next character below them on the tree who has not already been unlocked or issued a Challenger Approaching duel. For example, completing Classic Mode as with  already unlocked (or met in Challenger Approaching) will cause the challenger to be, even if  has not yet been unlocked or met in Challenger Approaching.

If the bottom of a tree is reached, the search resumes from the top of Mario's tree, then Donkey Kong's, and so on. Completing Classic Mode with downloadable fighters will also start from the top of Mario's tree, as these characters are not assigned an unlock tree. For example, completing Classic Mode as will receive a challenge from, even if some characters in Donkey Kong's tree have not been unlocked or met in Challenger Approaching yet.

Notably, all clones, semi-clones, and pseudo-clones except for, , and are in the same tree as the character they are based on.

Timed encounters
When the player finishes a VS. match, a Mob Smash, a Home-Run Contest round, a Spirit Board fight, or exits the World of Light, a new character may challenge the player to a Challenger Approaching duel. This character will be the one closest to the top of the list below who has not already been unlocked or issued a Challenger Approaching duel. However, the player must have performed enough in-battle stick inputs and, in most cases, have waited at least 10 minutes since the previous Challenger Approaching duel. (Quitting a match/mode other than World of Light will not cause a challenge, and neither will VS matches that only consist of CPUs or that are themselves Challenger Approaching matches.)

The in-battle stick input count considers the total since the save file was started. Its mechanics appear to be similar to how in VS matches is counted (for example, dash-dancing, Sudden Death, other Challenger Approaching matches, and jumping with the X Button do not count, but jumping with the Control Stick does count). However, unlike Gold, actions made in a VS match that is quit still count (they will not cause a challenge but will still contribute toward the total behind the scenes). If a controller disconnects during a VS match and it is still disconnected by the time the match ends, actions made by that player do not count (even though they count for Gold). Actions made during Classic Mode and World of Light count, excluding any Gold modifiers (e.g. due to difficulty level). Notably, the 5th through 30th characters in the list all have the same action count requirement, so meeting the requirement for any one of them will unlock all of them with no further in-battle actions required, provided that the wait time requirement is met between each one. Unlike the time requirements, the action count requirements cannot be changed. For example, unlocking through a timed encounter will always require approximately 8,100 actions, regardless of if any other characters have already been unlocked through any method.

The 10-minute delay requirement does not apply to the first five Challenger Approaching fights specifically. For example, if the player unlocks all but five characters through World of Light, then no time delay requirements apply to the remaining five regardless of who they are. However, Challenger Approaching fights initiated through Classic Mode will count toward the five despite Classic Mode not having a time delay requirement. For example, if the player's first Challenger Approaching fight is a character below on the list (regardless of if the player wins or loses), and then the player attempts to unlock the rest of the characters through timed encounters, then Inkling will require a 10-minute wait.

The player can bypass any wait time by closing the game and reopening it. (Note that changing the Language setting causes the game to automatically close and reopen.) The wait time applies regardless of if the previous Challenger Approaching fight was won or lost. Time spent idling on the title screen or loading screens counts, but time spent idling during a Challenger Approaching fight does not count (the time starts after the Challenger Approaching fight ends). Wait times do not carry over (if the player waits 20 minutes between one pair of Challenger Approaching fights, all future wait times are still 10 minutes).

Fighter table
Classic Mode and timed encounters result in the same Challenger Approaching fights.

The values listed under "Theoretical cumulative wait time" apply only if the player exclusively attempts to unlock characters through timed encounters, never closes the game after challenging Inkling, and never spends longer than the minimum time between Challenger Approaching fights.

Challenger's Approach
If the player loses any Challenger Approaching fight, that character will not appear again either from Classic Mode or as a timed encounter. However, the character will later reappear under Challenger's Approach on the Games & More menu.

World of Light
In the World of Light, only characters that have been awakened in the current World of Light save file can be used, with only initially being available. However, awakening a fighter in the World of Light that is not a starter character also unlocks them for the regular roster.

Awakening a Mii Fighter in the World of Light automatically creates a custom Mii Fighter of the awakened type.

Each fighter must be unlocked through a fighter battle, with a few exceptions:
 * is always available from the beginning.
 * is unlocked after defeating Giga Bowser within the Molten Fortress sub-world in The Light Realm.
 * Downloadable fighters become available after freeing a total of 10 fighters. If the player has already freed 10 fighters on a file, any characters downloaded afterwards will immediately be available.

The fighter battles all feature the same single condition: Win the battle to awaken the fighter

Trivia

 * In each of his unlockable appearances, Ness has always been the first one unlocked through Vs. Mode matches.
 * Super Smash Bros. 64 is the only game in the series in which playing VS. Mode matches cannot trigger a "Challenger Approaching" battle, and the only game in which each unlockable character only has a single unlock criterion.
 * When a player fights a secret character to unlock in Super Smash Bros. Brawl, their character always uses their default costume even if the player was originally using an alternative costume.
 * Starting in Super Smash Bros. 4, no items appear at all during the unlocking battle.
 * In Super Smash Bros. Brawl, each character unlock notification has a different tone depending on the debut game of the character.
 * Strangely, 's unlock notification tone is the same as the Brawl newcomers despite debuting in Super Smash Bros. 64. This is likely because it is unlocked in the post-game Subspace Emissary, as well as its internal ID being right next to and, Brawl newcomers. The other Smash 64 newcomers use "Rare Trophy" from Melee, Melee newcomers use the stage unlock fanfare from Brawl, and Brawl newcomers (alongside Jigglypuff) use the sound effect in Brawl when collecting songs or completing minor challenges.
 * In and Super Smash Bros. Ultimate, unlock matches are treated as VS. Mode matches - that is, they count towards the total number of VS. Mode matches, and all statistics accumulated during unlock matches are saved.
 * Masahiro Sakurai originally intended for all the characters in Super Smash Bros. for Wii U to be available from the start, but eventually decided against it.
 * In Super Smash Bros. 64, Super Smash Bros. Brawl,, and Super Smash Bros. Ultimate, the AI level of unlockable character fights starts out very low, but increases with each consecutive character unlocked.
 * In Super Smash Bros. Melee, the opposite is the case.
 * In Ultimate, the difficulty of the AI was lowered in patch 1.2.0, after notorious reports of the level of difficulty for each match.
 * Counting Super Smash Bros. for Nintendo 3DS and Super Smash Bros. for Wii U separately, Jigglypuff, Falco, and Mr. Game & Watch are tied for the most unlockable appearances, with five each.
 * Of the three of them, is the only one to be a starter character at any point, which was in Super Smash Bros. for Wii U.
 * Wario was the first starter character to become an unlockable character in a later installment. He is also the only character to have this distinction from Brawl to Smash 4.
 * is the only character whose moveset involves transforming into another character to become unlockable.
 * Prior to Super Smash Bros. Ultimate, the only unlockable characters whose playable status was not kept a secret in official material prior to release were and  in Super Smash Bros. Brawl, and  in Super Smash Bros. 4.
 * Out of all of these, Lucina is the only one who is not a third-party character.
 * Super Smash Bros. Ultimate is the first game to have more unlockable characters than starter characters, and the first game to feature unlockable characters on the box art.
 * While is a downloadable fighter rather than unlockable, from 17 December to 22 December 2020, defeating him through the limited-time Sephiroth Challenge enabled access to him, Northern Cave and his music if the player had purchased Challenger Pack 8 or Fighters Pass Vol. 2 prior to his official release.
 * In Ultimate, and  can have different music play during their regular unlock battles. Specifically, when they're unlocked between 8:00pm and 12:00am on Saturday, K.K. Slider will perform.