Poké Ball

When thrown, the ball opens up, and a Pokémon™ pops out. The Pokémon that appears is random; it performs its special skill then leaves. The Poké Ball (, Monster Ball) is an item from the universe.

Origin
Poké Balls are the most important items in the core games and several spin-offs, where they are used by Pokémon Trainers to catch wild Pokémon, store caught Pokémon and conveniently carry them around. Several different types of Poké Balls exist, which mostly increase the likelihood of catching a wild Pokémon in specific conditions. During battles, Pokémon are sent out by trainers by throwing the Poké Ball into the battlefield, which releases the chosen Pokémon with a burst of light. The Poké Ball serves as the series symbol for the Pokémon series.

Since the Poké Ball's debut in the Smash series, the characteristic sound effects from the Pokémon anime have been incorporated into its design. From Brawl onwards, the Poké Ball makes a distinct, hollow noise when it lands on the battlefield. The sound, initially used only when switching Pokémon in the games, was first associated with landing Poké Balls in the anime. This behavior was later incorporated into the games starting with Gold and Silver, and has since consistently appeared in each subsequent installment.

Use
When thrown, it releases a random Pokémon upon landing. Each Pokémon has a different effect, such as attacking the summoner's opponents, changing the properties of the stage, and inducing status effects. The Pokémon available change between games, with every new release adding several Pokémon which tend to come from the most recent s. Not every Pokémon returns in subsequent games, with some being replaced in function by newer Pokémon and some others disappearing completely.

Since Super Smash Bros. Brawl, the Poké Ball makes a unique sound effect when it hits the floor (the Poké Ball bouncing sound from the Pokémon games and anime), thus alerting players to its presence even if it appears off-screen. Also, reflecting a thrown Poké Ball will change its ownership, and the Pokémon summoned from it will belong to the reflector rather than the thrower.

In the first Super Smash Bros., up to 4 Poké Balls can be on-screen at the same time. This number was increased to 12 in Super Smash Bros. Melee. The number was reduced to 3 in Brawl and remains 3 in and Super Smash Bros. Ultimate. In the limit is only 1, perhaps due to limited rendering power.

Another version of the Poké Ball, the Master Ball, was introduced in Smash 4, which has the same function as the Poké Ball but only releases Legendary Pokémon, with a couple of exceptions.

Non-item Poké Balls appear during the on-screen appearances of most playable Pokémon in every game except for Melee, and are thrown by the Pokémon Trainer for his Pokémon Change. Only Mewtwo and Lucario do not emerge from a Poké Ball during their on-screen appearances.

Damage
In SSB4, damage varies based on distance. Projectiles thrown point-blank do more damage. Projectiles thrown or dropped vertically will do more damage at a greater distance. However, in most cases, the Poké Ball either does fixed damage or doesn't even hit.

Super Smash Bros.
There are thirteen Poké Ball Pokémon in Super Smash Bros.. Unlike later games, all Poké Ball Pokémon are depicted as 2D sprites.

Super Smash Bros. Melee
There are twenty-nine Poké Ball Pokémon in Melee.

Ditto was also planned, but cannot appear from a Poké Ball in the final game. It was originally intended to transform into its summoner and fight alongside them as a CPU player. However, it was removed due to technical difficulties with implementing its behavior. Ditto is still accessible through hacking, but it just cries Mon-mon (from "Metamon", its Japanese name) and then disappears.

Super Smash Bros. Brawl
There are thirty Poké Ball Pokémon in Brawl. Pokémon with a given frequency of 0 are assigned a combined 1/493 chance of appearing, independent of the rest of the frequency system.

Super Smash Bros. 4
There are forty Poké Ball Pokémon in Smash 4. Unlike other installments, there are unlockable Poké Ball Pokémon, with two only being unlockable on the 3DS version.

Super Smash Bros. Ultimate
There are fifty-five Poké Ball Pokémon in Ultimate, and as prior to Smash 4, all Pokémon are available from the start. Certain Pokémon cannot be summoned on certain stages.

In Super Smash Bros. 4
The Poké Ball trophy appears in both versions of the game. In it is part of the Pokémon Gold & Pokémon Silver.

Trivia

 * Charizard is the only Poké Ball Pokémon in the series to become a playable character in later installments.
 * Prior to Smash 4, the chance of encountering Mythical Pokémon has varied depending on the number of Pokémon available in the main Pokémon series upon the Smash game's release.
 * Mew has a 1 in 151 chance of appearing in Super Smash Bros., referencing the number of Pokémon available in.
 * Mew and Celebi each have a 1 in 251 chance of appearing in Melee, referencing the number of Pokémon available in.
 * Mew, Celebi, and Jirachi each have a 1 in 493 chance of appearing in Brawl, referencing the number of Pokémon available in.
 * At the time of Brawls release, only 492 Pokémon were revealed as Arceus wouldn't be revealed until the August 3rd, 2009 (over a year after Brawls release).
 * In Melee's Training Mode legendary Pokémon do not appear, and a few Poké Balls may not release any Pokémon at all, possibly to prevent the player from grinding for Mew and Celebi.
 * Similarly in Brawl and Smash 4, Mew (in both), Celebi, and Jirachi (both in Brawl) will not appear in Training Mode. Mew will appear in Training Mode in Ultimate, either randomly or by being directly picked.
 * Charizard, Meowth, Goldeen, Snorlax, Mew, Electrode, and Moltres are the only Poké Ball Pokémon to appear in all five Super Smash Bros. games. Charizard, Electrode, and Moltres appear in some capacity in every game, with Charizard being playable since Brawl and Moltres and Electrode occasionally appearing in the background of Saffron City. Meowth was a trophy in Melee. Only Goldeen, Snorlax, and Mew remained as Poké Ball Pokémon in all appearances.
 * In  Melee, all Poké Ball Pokémon models are reused from Pokémon Stadium, Pokémon Stadium 2, and Pokémon Snap, respectively. In Super Smash Bros. Brawl, all Poké Ball Pokémon models are reused from Pokémon Colosseum, Pokémon XD: Gale of Darkness, and Pokémon Battle Revolution, respectively. Starting with Super Smash Bros. 4, all Poké Ball Pokémon are reused from Pokédex 3D Pro and Pokémon X and Y onwards (this is most apparent with Gardevoir's walking animation).
 * Every Generation IV Poké Ball Pokémon introduced in Brawl had its Poké Ball role removed in Smash 4, with only Piplup and Manaphy being changed into background characters on Kalos Pokémon League.
 * Abomasnow is the only Generation IV Poké Ball Pokémon from Smash 4 onwards that is neither a Legendary nor Mythical Pokémon.
 * The Staryu and Koffing evolution lines are the only Poké Ball Pokémon to replace another member of their evolution line in later installments.
 * Vulpix is the first Poké Ball Pokémon to appear alongside an alternative version of itself, being its Alolan Form.
 * Likewise, Raichu, Vulpix, and Exeggutor are the only Pokémon who appear in their Alolan forms.
 * Totodile, Tepig, and Froakie are the only members of their region's starters that haven't appeared as Poké Ball Pokémon. However, Froakie's final evolution, Greninja, appears as a playable character.
 * Likewise, Torchic and Piplup are the only members of their region's starters that have appeared as Poké Ball Pokémon.
 * Kanto is the only region to have all three of its starter Pokémon appear as Poké Ball Pokémon.
 * Likewise, it is the only region to have starter Pokémon appear in their fully evolved forms rather than their first-stage forms, with all three being fully evolved.
 * Prior to Ultimate, it is possible for multiple of the same Pokémon to appear at the same time in Training Mode, which cannot happen in normal battles.
 * Many of the Pokémon use moves that they cannot normally use in the games. For example, Goldeen cannot learn Splash in the Pokémon games.
 * Ultimate is the first game where no Pokémon from the previous game were removed.
 * Meowth and Scizor are the only Poké Ball Pokémon to be cut and return in a later installment.
 * Some Poké Ball Pokémon cannot appear in a Pokémon stage that features said Pokémon in the background in Ultimate. For example, Palkia cannot be summoned in Spear Pillar. Despite having Moltres appear in the background of Saffron City, Moltres can still be summoned there.
 * Brawl is the only game to not add a new Gen I Pokémon. However, it does bring back Meowth, who was absent from Melee.
 * Generation VII is the most recent generation represented in the series to have any Pokémon appear as Poké Ball Pokémon in the game it was first represented in, due to Pokémon Sword and Shield releasing after the initial launch of the game, and its representation being added later in the form of spirits.