Pokémon Change is Pokémon Trainer's Down Special Move. It is one of only two moves that all three of the Trainer's Pokémon have in common (the other being Triple Finish). It switches between his three Pokémon - Charizard, Squirtle, and Ivysaur. If Charizard is currently in use, it will switch to Squirtle. If Squirtle is in use, it will switch to Ivysaur. If Ivysaur is in use, it will switch to Charizard. Using this move too little will result in the Pokémon's stamina being drained. Only one Pokémon needs be knocked out to score against Pokémon Trainer.
If one Pokémon is KO'd, Pokémon Trainer will summon the next Pokémon in the rotation to the revival platform. The Pokémon Change cannot be used again until the starting invincibility has worn off. To prevent taking advantage of recovery (like switching to Charizard to avoid being edgehogged with Ivysaur's recovery), Pokémon cannot be changed in midair.
While changing, there is a little time in which you are invincible. You can utilize this minor invincibility to "dodge" various attacks, most notably Final Smashes.
Notably, using Pokémon Change ends nearly all status effects on the Pokémon, both positive and negative. This includes super or mini size, Starman invincibility, metal form, Franklin or Screw Attack badges, etc. The exceptions to this rule are slowed-time, healing in progress, and Smash Ball readiness, which remain through the change. Any held item is immediately dropped.
Like Zelda's Transform, the next Pokemon to appear must be loaded from the disc before the switch can be completed. Pausing can shorten the in-game switch time (since the game loads during the pause), as can lag when online. If the switch time is artificially shortened as such, replays will temporarily freeze at the point the switch is made (since it must take the full time to load).
Stamina
Each Pokémon starts with 120 points of "stamina". For each second that that Pokémon is on the battlefield, the stat decreases by 1. Every attack that Pokémon performs while it is on the battlefield will reduce the stat by an additional 1 point. If the stat reaches 36, the Pokémon's standing animation changes so that they appear fatigued, and when it reaches 0, all attacks will have less knockback and damage. While another Pokémon is active, if a Pokémon's stamina is below 120, it will restore at the rate of 2 per second, to a max of 120. Each Pokémon's stamina is reset to 120 when one of them is knocked out.
Trivia
- With very precise timing, Pokémon Change could be used to avoid all three of Tabuu's Off-Waves.
- While Pokémon Change isn't necessarily an offical term in the Pokémon universe, it does describe the act of switching a Pokémon mid-battle.