201,Forms only affect appearance. A form is selected at random before a wild encounter and cannot be changed.
351,Form changes to match the current weather.
386,"Forms have different stats and movepools. Form changes depending on the game: normal form in Ruby/Sapphire, Attack form in Fire Red, Defense form in Leaf Green, and Speed form in Emerald. Every form exists in Diamond/Pearl/Platinum, and form is preserved when transferring from an older game. Meteorites in the south end of Veilstone City can be used to switch between forms."
201,Forms only affect appearance. A form is selected at random before a wild encounter and cannot be changed.
351,Form changes to match the current weather.
386,"Forms have different stats and movepools. Form changes depending on the game: normal form in Ruby/Sapphire, Attack form in Fire Red, Defense form in Leaf Green, and Speed form in Emerald. Every form exists in Diamond/Pearl/Platinum, and form is preserved when transferring from an older game. Meteorites in the south end of Veilstone City can be used to switch between forms."