Tri-Horn Dragon Card
Enter the following name: GOD OF CARDS

Unlock Cosmo Queen Card
Enter the following name: KONAMI

Unlock Zera the Mant Card
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Press X at the menu with the single or triple duel options to change the background to that of one of cards that you have unlocked.

Getting to the next level is quite easy. If the order is easy, medium, hard, it could be a challenge. However, by putting them in hard, medium, easy order you can save your life points for an easy person. You should be able to complete it.

To get easy magic and trap cards, unlock the Rare Hunter in triple duels. Then, just keep defeating him until you get the cards that you need. He has all the best magic and trap cards required for a deck. Note: He three sets of Exodia and multiple limited cards such as Pot Of Greed.

Get the magic card that stops all trap cards and set it down face up. Then when you attack, there are not any trap holes. This is very useful against Grandpa, because he mostly has trap hole.

If you saved before the match and you know that you are going to lose, instead of waiting for the rest of the turns to go by, hold Back + Start to do an in-game reset to save time.

Use this trick when you face Grandpa or Rare Hunter, as they are the only ones that have Exodia the Forbidden One. Jack most of your deck with cards that make your opponent discard cards from their deck and/or hand. Most of the time against Grandpa this trick will work. However, against Rare Hunter it is a challenge because he has three sets of Exodia compared to Gramp's single set.

To get your desired characters for single dueling, you must put them last and defeat the team.

Unlock kaiba in single duel keep defeating him and getting the obelisk statue.
Enter the following name: KONAMI
Enter the following name: XBOX