Fighter

A fighter, also known as a playable character or simply character, is a character (or in some cases, multiple characters simultaneously) in the  series roster that can be controlled by players in Versus Mode and other modes. These characters are located on the character selection screen and can be used without a cheat device (e.g. Action Replay). Playable characters can further be divided into starter, unlockable, and downloadable, which distinguishes whether characters can be played right away, whether they need to be unlocked, or whether they need to be downloaded.

List of fighters
This is a list of the fighters in the Super Smash Bros. series.

The following does not include some bosses who can be playable on occasion, such as in the World of Light.

For characters who were considered or intended to be fighters, see Unused content (SSB), Unused content (SSBM), Unused content (SSBB), Unused content (SSB4), and Unused content (SSBU).

Newcomers and veterans
A newcomer is a character who appears as playable for the first time in the series in a given game. A veteran is the opposite: a character who has been playable in a previous game. For example, Diddy Kong is a newcomer in Brawl, as he did not appear as playable in any previous games, but is a veteran in all subsequent games. Note that the definition of newcomers is distinct from that of "unlockable" or "secret" characters, which are playable characters who must be unlocked by completing certain tasks; Melee, Brawl, and Smash 4 all had starter veterans, starter newcomers, unlockable veterans, and unlockable newcomers. Ultimate is the first game in which all newcomers to the base game are unlockable; however, most veterans are also unlockable.

The term newcomer was originally used to describe the unlockable characters in the original Super Smash Bros. by the data deletion menu. It was later used in the first trailer for Super Smash Bros. Brawl, in which new characters were introduced with the title "Newcomer" atop their name. The word newcomer was later used on the Smash Bros. DOJO!! site to classify characters who made their debut in Brawl and are starters in there, in addition to third party characters Snake and Sonic. This use of the term has become the community-preferred usage for other games in the series.

"Perfect-attendance crew"
Less commonly, the term "veteran" can also denote the "eight regulars" or "perfect-attendance fighters", which are the eight starter characters in the original Super Smash Bros. which have been in all subsequent games of the series. The "perfect attendance" part of the term is a reference to the fact that these eight fighters have always been available from the start of every game without needing to be unlocked. The terms originated in the description for the 10th Brawl event match All-Star Battle Regulars, reading: "The Smash Bros. perfect-attendance crew! Fight the eight regulars in order!" A popular, unofficial term referring to this group is "The Original 8" (Mario, Donkey Kong, Link, Samus, Yoshi, Kirby, Fox, and Pikachu), which may also be called "The Original 12" if including the four unlockable characters (Luigi, Ness, Captain Falcon, and Jigglypuff), who have likewise appeared in every game in the series. The 29th Brawl event match All-Star Semifinal Regulars states: "Four hidden characters from the past game! They're secret perfect attendees." is the only installment where all the "Original 12" are starter characters. Super Smash Bros. Ultimate refers to the concept of the perfect-attendance crew by making the only starter characters the aforementioned "Original 8".

Trivia

 * is the only universe to have multiple fighters cut throughout the series, being Mewtwo, Pichu, and Pokémon Trainer's Squirtle and Ivysaur.
 * and are the only universes to have the entirety of their characters cut from a game.
 * Pichu and Young Link are the only fighters to have been absent from multiple consecutive installments.
 * Ice Climbers are the only characters to have been a fighter in multiple games before being cut.
 * Lucas is the only fighter to have been a starter character, unlockable character, and downloadable character in separate games. Lucas is also the only playable character who has never appeared in a non-Smash game released outside Japan.
 * Roy is the only playable character to debut in Super Smash Bros. before appearing in any other game. His inclusion in Melee was intended to promote , his debut in his home series, which was released shortly after Melee in Japan. According to Masahiro Sakurai, The Binding Blade was originally scheduled for release before Melee.
 * Charizard, Little Mac, Ridley, Dark Samus, Isabelle, and Chrom are the only characters to have been made fully playable after major non-playable appearances, excluding characters that are playable via items such as Metal Mario. These include Poké Ball Pokémon, Bosses, Assist Trophies, or part of another character's moveset. Of these characters, Chrom is the only one to retain his non-playable role even after becoming playable.
 * Charizard is the only character who was part of a transformation character, became a standalone fighter, and then returned to being part of a transformation character.
 * Inversely, Samus is the only character who was initially a standalone character before being able to transform into Zero Suit Samus, before the two were split in their next appearances.
 * (in Smash 64), the s in both of their appearances, and (in Ultimate) are the only fighters to use head icons that don't portray their faces.
 * Prior to Ultimate, the only unlockable characters whose playable status was not kept a secret in official sources prior to release were and  in Brawl, and  in Smash 4.