Trade

Trading is one of the ways that you can complete the Pokédex. You can use trading to get other Pokémon that you would like, or you can use trading to evolve certain Pokémon.

Process

There are several ways to trade Pokemon between games.

A trainer trading a Mantyke for a Turtwig

1. In Generation I and II, Pokemon can be traded between games of the same generation from the Link Club. The Link Club can be found on the 2nd floor of any Poke Center. 
2. Pokemon from Gen. II games can be traded to Gen. I games using the Time Capsule, which can be found on the 2nd floor of any Poke Center.
3. Generation III games cannot trade with games from Generations I or II. This is due to the game mechanics being completely revamped in Gen. III games.
4. In Generation III, the games set in similar regions can trade via the Wireless Club on the 2nd floor of the Poke Center. However, in order to trade between FireRed or LeafGreen and Ruby, Sapphire, or Emerald, the trainer must first help Celio fix the inter-regional trading machine on One Island after defeating the Elite Four .
5. In Generation IV, Pokemon can again be trade between games via the Wireless Club on the second floor of any Poke Center. In addition, Pokemon can now be traded over wi-fi at the Global Trading Station in Jubilife City with other Gen. IV games all over the world.
6. In Generation V, it is possible to trade via the C-Gear from almost anywhere in Unova, not just in the Poke Centers like previous generations. The only restriction is that nothing with an HM can be traded.
7. In Generation VI, there is a feature called Wonder Trade, which has you send a Pokemon out and almost immediately recieve a random Pokemon from a random player.

Notes

• Traded Pokémon cannot be given a new nickname, including Pokemon named in a different language.
• Pokemon that were traded from a different game recieve a 1.3x experience boost on any experience points they recieve.