Trade someone with Ruby,Sapphire,and Emerald.
You must Migrate from Sapphire, Ruby or Emrald.
either you get Pokemon emerald or Sapphire, and if you want them on diamond or pearl you have to beat the elite four and then migrate.
you cant get the three regi's in heart gold or soul silver. You can only get them in Pearl, Diamond and Platnium
trade them
On Pokemon platinum, diamond, and pearl you have to get regirock, registeel, and regiice then you go to the snowpoint temple and go to the end and regigigass will be there talk to him and he will battle you.(you HAVE TO have the three regis- with you. on all the other ones you cant but you can get the three regi. forgot to get the three regis n platinum and diamond and pearl you have to migrate them. Hoped this helps!
It is only possible by cheating.Not by regular gameplay.
Nothing special, but if you migrate them over to Diamond, Pearl, or Platinum, when they are at the same level, you can get Regigigas.
you cant you can only cacth regice regirock and registeel.you cacth regigigas by migrating the regis to diamond pearl and platinum.In platinum hes at lvl 1, in pearl or diamond at lvl70. hes at snowpoint temple that the girls blocking. Bring all three regis and she lets you in.
I believe their isn't a code you can't get the regi's in Pokemon pearl unless you trade.
There are no 'Grand Lakes' in Pokemon Diamond and Pearl, but there are the three lakes that have Uxie, Mespirit and Azelf.
You need to get the special movie Regigigas.
Unfortuately, no. You must migrate the Three Regis from the GameBoy Pokemon Cartridges to form Regigigas. It's twice the challenge because you have to catch the Three Regis and migrate them into Pearl/Diamond/Platinum, but it's also twice the fun.