There aren't that many Mega Evolutions in Pokémon Xand Y,???? ??? but there are probably more than you think, making it even more difficult to catch ’em all.

In order for a Pokémon to undergo a Mega Evolution, it needs to be holding a Mega Stone appropriate to its type, and the trainer needs to be wearing the Mega Ring. If both conditions are met and the Pokémon is able to mega evolve, then you can select the option from within a battle to trigger the Mega Evolution.

Only one Pokémon can mega evolve during a battle, but that isn’t too bad of a limit considering the game’s random encounters run rampant, and triggering a Link Battle is easy enough. Each available Mega Evolution is listed below along with its corresponding Mega Stone location.

Pokémon X Mega Evolutions

• Mega Venusaur: If Bulbasaur is chosen as your second starter, it comes with its Mega Stone, Venusaurite. If not, you can pick it up at Vernal Avenue Stone Emporium in Lumiose City.

• Mega Charizard X andY: If Charmander is chosen as your second second, it comes with its Mega Stone, Charizardite X or Y. If not, you can pick it up at Vernal Avenue Stone Emporium in Lumiose City.

• Mega Blastoise: If Squirtle is chosen as your second starter, it comes with its Mega Stone, Blastoisinite. If not, you can pick it up at Vernal Avenue Stone Emporium in Lumiose City.

• Mega Alakazam: You can find this stone, Alakazite, in the Reflecting Cave, floor B3F, during the post-game.

• Mega Gengar: You will be given this stone, Gengarite, in Laverre City.

• Mega Kangaskhan: You can find this stone, Kangaskhanite, in the Glittering Cave during the post-game.

• Mega Pinsir: You can find this stone, Pinsirite, in the Santalune Forest during the post-game. It is exclusive to Pokémon X.

• Mega Gyarados: You can find this stone, Gyaradosite, in Couriway Town during the post-game.

• Mega Aerodactyl: You will be given this stone, Aerodactylite, in Ambrette Town.

• Mega Mewtwo X and Y: Mewtwo is holding this stone, Mewtwonite X or Y, upon capture. He’s located in a cave in the Pokémon Village that requires Surf to access.

• Mega Ampharos: You will be given this stone, Ampharosite, in Azure Bay.

• Mega Scizor: You can find this stone, Scizorite, in the Frozen Cavern located behind Abomasnow.

• Mega Heracross: You can find this stone, Heracronite, in Santalune Forest during the post-game. It is exclusive to Pokémon Y.

• Mega Houndoom: You can find this stone, Houndoomite, in Route 16 during the post-game. It is Pokémon Yexclusive.

• Mega Tyranitar: You can find this stone, Tyranitarite, in the Cyllage Gym during the post-game. It is Pokémon Xexclusive.

• Mega Blaziken: When you get Torchic from the event giveaway, it’ll come with this stone, Blazikenite.

• Mega Gardevoir: In the Lumiose City southern boulevard cafe, you can trade for a Ralts. The Ralts holds this stone, Gardevoirite.

• Mega Mawile: You can find this stone, Mawilite, in Shabbneau Castle during the post-game.

• Mega Aggron: You can find this stone, Aggronite, in the Cyllage Gym during the post-game. It is Pokémon Yexclusive.

• Mega Medicham: You will be given this stone, Medichamite, in Laverre City during the post-game.

• Mega Manectric: You can find this stone, Manectite, on Route 16 during the post-game. It is Pokémon Xexclusive.

• Mega Banette: You can find this stone, Banettite, in the Cave of Emptiness during the post-game.

• Mega Absol: You will be given this stone, Absolite, in Kiloude City during the post-game.

• Mega Garchomp: You can find this stone, Garchompite, on Victory Road during the post-game.

• Mega Lucario: You can find this stone, Lucarionite, held by the Lucario gifted to you in the game. You can turn down this Lucario, but if you want the stone and not the critter, just set the Pokémon free after you take its stone.

• Mega Abomasnow: You will be given this stone, Abomasite, at the Frozen Cave where you obtain Abomasnow.

So, while Pokémon Xand Y technically has every single Pokémon since the series inception, it only has a handful of Mega Evolutions. However, since the mechanic has now been introduced, it’s safe to assume subsequent installments in the franchise will build upon the new evolution mechanic. It would probably be best to evolve ’em all this time around, so you can fill out your Pokédex now and not have to worry about it in later installments.

This story originally appeared on Geek.