--- title: "Mega Evolution: Pokémon Mechanics Explained | pokee.si" url: "https://pokee.si/guide/mechanics/mega-evolution" description: "The temporary power-up from Pokémon X and Y: what it needs, what it changes and which games have it. Guide on pokee.si." last_updated: "2026-10-19" publisher: "pokee.si: a Pokédex for families (unofficial fan site)" --- # Mega Evolution The temporary power-up from Pokémon X and Y: what it needs, what it changes and which games have it. Mega Evolution is a temporary transformation that makes a fully evolved Pokémon much stronger. It first appeared in Pokémon X and Y in 2013, took a seven-year break after Generation VII, and came back in Pokémon Legends: Z-A. ## What you need Two special stones are needed: the Trainer must have a Key Stone (built into a Mega Ring in X and Y, or a Mega Bracelet in Omega Ruby and Alpha Sapphire), and the Pokémon must hold its own Mega Stone, such as Charizardite X or Gengarite. Only Pokémon that cannot evolve any further can Mega Evolve. Rayquaza is the exception that needs no Mega Stone: it only has to know the move Dragon Ascent. In the games, the Pokémon's friendship does not matter, even though the story says Mega Evolution depends on a strong bond. ## What it changes A Mega-Evolved Pokémon gets new base stats, apart from HP. For almost all of them the new base stat total is exactly 100 points higher, and the extra points are usually pushed into a few stats. Many gain a new Ability that works only while they are Mega Evolved (Mega Venusaur always has Thick Fat), and some change type: Mega Ampharos becomes Electric and Dragon, Mega Gyarados becomes Water and Dark, and Mega Aggron loses its Rock type to become pure Steel. ## The battle rules In Generations VI and VII each Trainer could Mega Evolve only one Pokémon per battle. It happens at the start of a turn, as a free action alongside choosing a move, and it lasts until the Pokémon faints or the battle ends (it stays Mega Evolved if you switch out). Stat and type changes take effect straight away. Mega Evolved Pokémon cannot use Z-Moves, and Mega Stones cannot be knocked off or swapped away from a Pokémon that can use them. ## How many are there? There are 93 different Mega Evolutions (96 if you count a few variations). They arrived in waves: - Pokémon X and Y: 30 Mega Evolutions for 28 Pokémon. - Pokémon Omega Ruby and Alpha Sapphire: 18 more. - Pokémon Legends: Z-A: 26 new ones in the base game. - Mega Dimension (the Z-A DLC): 19 more, including the new Z Mega Evolutions. There are 92 Mega Stones, which cover 86 different species (every species that can Mega Evolve except Rayquaza). Some Pokémon have two Mega forms: Charizard and Mewtwo have X and Y, and Lucario, Garchomp and Absol have a second "Z" form. ## Where it appears Mega Evolution is a mechanic of Generation VI and VII, including Pokémon: Let's Go, Pikachu! and Let's Go, Eevee!. It was missing from the Switch games of Generations VIII and IX (Sword and Shield, Scarlet and Violet) and returned in Legends: Z-A with a new real-time system. It also appears in spin-offs like Pokémon GO, Pokémon UNITE and Pokémon Champions. ## Lore in brief In Omega Ruby and Alpha Sapphire, the first Mega Evolution was Rayquaza's, about 1,000 years ago in Hoenn, when it calmed a battle between Primal Groudon and Primal Kyogre. Games set in Kalos say the first Mega Evolution in that region was Lucario's. Professor Sycamore, in Pokémon X and Y, suggested Mega Stones may be linked to a terrible weapon used long ago. Diancie is the first Mythical Pokémon able to Mega Evolve. ## Related - [Legends: Z-A Mega features](https://pokee.si/guide/mechanics/legends-za-mega) - [Z-Moves](https://pokee.si/guide/mechanics/z-moves) - [Items (Mega Stones)](https://pokee.si/guide/items) --- Source: https://pokee.si/guide/mechanics/mega-evolution (HTML page). pokee.si is an unofficial fan site and is not affiliated with Nintendo, Creatures, GAME FREAK or The Pokémon Company. Pokémon and all related names and images are © their respective owners.