"Pokemon X" and "Pokemon Y" contain a few different version-exclusive types of Pokemon and Mega Stones. The games are otherwise identical and feature the same characters, story and non-exclusive Pokemon and Mega Stones.
The developers released the "X" and "Y" versions of the game with exclusive content to encourage players to trade items with each other.
There are a few different ways to trade with other players using the Player Search System. The PSS displays the icons of friends, acquaintances and nearby players who are available to trade. Players can also use Wonder Trade, which trades any selected Pokemon for a random Pokemon from another player. Finally, players can access the Global Trade Station to search for desirable trades with people from all over the world. A player can enter the parameters of the trade, including the Pokemon desired, its level and its gender, and then search to find a compatible trade partner.
Mega Stones give players access to extremely powerful Pokemon evolutions. Players can trade them with friends or by using the Global Trade Station. Be cautious when trading for a Pokemon of a significantly higher level than the character, because these Pokemon frequently disobey the trainer by using incorrect moves or falling asleep. Gain badges at high-level gyms to earn the Pokemon's respect.