Mega Evolution (Japanese: メガシンカ Mega Evolution) is a transformation method of a Pokémon which was introduced in Generation VI. Pokémon that undergo this transformation have the word "Mega" in front of their name.
This form of transformation can only be done during a battle and certain conditions must be met. Only one Mega Evolution is allowed per team. Mega Evolution is said to require a bond between the Pokémon and the trainer: requiring the Pokémon's specific Mega Stone (with the exception of Mega Rayquaza, which must know the move Dragon Ascent) and a trainer's Key Stone, which is usually mounted into jewellery.
To unlock this transformation, in the Kalos region one must first talk to a Gym Leader named Korrina, located in Shalour City after acquiring her badge. It has been noted that the Tower of Mastery, also located in Shalour City, is focused around Mega Evolutions, even having a large Mega Lucario statue placed in the main entrance.
A Key Stone is necessary for the trainer's use to Mega Evolve a Pokémon. This is mounted into:
- the Mega Ring in X and Y
- the Mega Bracelet in Omega Ruby and Alpha Sapphire
- or the Z-Ring in Ultra Sun and Ultra Moon.
Those Pokémon who undergo a Mega Evolution may have its stats, abilities, type, and/or its appearance changed.