Yes you can with two ways.First way is to trade from Pokemon pearl diamond and platinum.Second way is throught an event of Pokemon archeus
you either trade or do the arceus event
No, but you will be able to catch Palkia, Dialga or Giratina.
Yes! First get an arceus. Then go to ruins of alph. Cynthia will be there and then you go to Shinto ruins. Then you can catch one of the 3 legends: Giratina palkia dialga.
No you only catch it in diamond,pearl,and platinum and in soulsilver and heartgold you get an arceus and solve the ruins of Alph.
You cannot get Dialga in HeartGold version.
You can't catch Dialga, Palkia, or Giratina in Pokemon SoulSilver/HeartGold. The only way to get them is by trade, or if you got the special Arceus given away during the movie: "Arceus and the Jewel of Life".
Shinto Ruins
Yes, go to pokemongoldsilver.com for information.WARNING! Dialga will be at level 1 if you get him.
If you beat Dialga and Dialga faints, you can no longer catch it.
It depends on which game. you can catch dialga on pearl with a code
You can catch it by first turning Dialga's HP into the red. Then use Ultra Balls or Dusk Balls to catch Dialga. It will take time, and you need to use a few balls to catch Dialga.
If you got the Arceus from an event and you send it to heartgold, go to the ruins and you will find Cynthia. Then you can choose between Dialga, Palkia and Giratina, lvl 1!