RE: The Questions and Answers Thread (All generations, excluding 5th)
Secret Pikachu said:
Thank you for the great information! Based on that, you can't trade Pokemon from one generation to the previous generation (except for RBY and GSC)?
That's correct.
Here's a quick rundown. Note that all games in the same generation may trade freely with one another.
Gen 1: RBY
Gen 2: GSC
Gen 3: RSE and FRLG (note, there is a small restriction on trading between FRLG and RSE, but that restriction is removed by doing an in-game sidequest after the National Pokedex is obtained)
Gen 4: DPPt and HGSS
Gen 5: BW1 and BW2
Trading between gens:
RBY can trade with GSC - on the condition that, in the GSC player's party, there are no moves or Pokemon that didn't exist in RBY.
GSC cannot trade forward at all.
RSE and FRLG can trade with each other, but to trade forward, they must use the Pal Park feature, unlocked after beating the Champion in DPPt/HGSS. This is called "migrating". You pick 6 Pokemon and they are sent, one-way, permanently, to the 4th Gen game.
DPPt and HGSS can trade with each other, but to trade forward, they must use the Poke Transfer feature in BW1 and BW2, unlocked after beating the Champion. Again, this is a form of migrating - it is one-way.
~GSC is the
only set of games that can trade backwards by a generation.
~When migrating Pokemon, they can't know any HMs. (In migrating to BW, the items will also not be transferred.) Migrating is permanent; you can send them forward, but you cannot send anything backward.
I'm basically just expanding on what was already said.