A trade occurs when two trainers exchange Pokémon. Trades can be conducted either with a trade machine (player to player) or using traders (player to NPC). Trading causes happiness to be reset to 70, but no other aspects of the traded Pokémon are affected. Unlike in the Pokémon games, traded Pokémon do not gain boosted experience and have no chance of disobeying their new owners regardless of their levels.
Several Pokémon only evolve when traded. The majority of these Pokémon are unavailable legitimately in single player, although Machamp, Golem, Gengar, Steelix and Gigalith can be obtained as traders may potentially offer them or their pre-evolutions.
Some evolutions also require that the Pokémon is holding a specific held item.
- Poliwhirl→Politoed (King's Rock)
- Slowpoke→Slowking (King's Rock)
- Onix→Steelix (Metal Coat)
- Rhydon→Rhyperior (Protector)
- Seadra→Kingdra (Dragon Scale)
- Scyther→Scizor (Metal Coat)
- Electabuzz→Electivire (Electirizer)
- Magmar→Magmortar (Magmarizer)
- Porygon→Porygon2 (Up-Grade)
- Porygon2→Porygon-Z (Dubious Disc)