As with the previous games, the player takes on the role of a human who has been turned into a Pokémon, whose type is determined by a personality test.[4] A partner Pokémon is also selected who will henceforth be referred to as "the partner". Unlike Blue Rescue Team and Red Rescue Team, the gender does not restrict the available selection of Pokémon for either the player or the partner, though both player and partner may not be of the same type. The test sets the player as one of the many natures in the mainstream games, and two Pokémon will be set to that nature, one for male, one for female.
The player may be Bulbasaur, Charmander, Squirtle, Pikachu, Meowth, Chikorita, Cyndaquil, Totodile, Treecko, Torchic, Mudkip, Skitty, Turtwig, Chimchar, Piplup and Munchlax; a total of 16 Pokémon to choose from. Once chosen, the partner may be any of the above Pokémon, with the exception of Pokémon of the same type of the player, Meowth, Skitty and Munchlax. Eevee, Machop, Cubone and Psyduck were removed as starter Pokémon, though Eevee was again made available in Explorers of the Sky. Riolu was debated for a player Pokémon in Explorers of Time and Darkness, but the idea was eventually dropped, and Riolu was selected for the Explorers of Sky list.