Q&A for How to Catch Dialga and Palkia in Pokémon Omega Ruby and Alpha Sapphire

You must have Mesprit, Uxie, and Azelf in your active party to trigger the encounter.

Yes, as long as the last save was at a point where you could catch Dialga or Palkia.

Go back to the cave at other times of day.

If you mean you've killed them, yes, you can encounter them again. However, if you captured them, no.

Palkia and Dialga are version-exclusive Pokémon; you cannot find both in a single game version.

Not through this method. It is required to trade or redeem special event codes to get Palkia in Alpha Sapphire.

No, you just have to hope you get lucky, unless you use the Master Ball, which is an instant, guaranteed capture. Any Poke Ball can catch it, even a ball you might not expect to catch it like a Net Ball.

Uxie, Mesprit and Azelf are one-time only catches per save file. This means that trading among other save files, whether from friends or files of your own, is required to encounter Dialga and Palkia.

No, you can catch Dialga or Palkia at any time. You only need Uxie, Mesprit, and Azelf in your party.

No, you must have all three members of the Lake Trio (Uxie, Azelf, and Mesprit) in your party simultaneously to encounter Dialga and Palkia.

Uxie is arguably the hardest to find. It appears from 8PM to 9PM on your 3DS' clock.

As you have Alpha Sapphire, you can't encounter Palkia. You need to trade from another game in order to obtain Palkia.

No, you cannot obtain two of the same legendary Pokémon without trading.

There is no specific code to obtain Dialga. You can acquire it by following the steps outlined in this article.

Yes - with Omega Ruby or Alpha Sapphire, you can trade with copies of Omega Ruby, Alpha Sapphire, Y and X.

Yes, if you accidentally defeat Uxie in battle without catching it, you can encounter it again.

No. Palkia is version-exclusive (as you cannot find Dialga in Omega Ruby), so you cannot find it in your Alpha Sapphire copy.

Yes.

No. The Lake Guardians are a one time only encounter. Be sure to save before legendary battles in the future.

No, you do not need to catch them again. If you have transferred the Lake Trio from another game, they simply need to be in your party.

You should begin the battle by throwing a Quick Ball. If this doesn't work, weaken Mesprit and use Ultra Balls. Once thirty turns have passed, you can switch to Timer Balls for better results.