At the arena selection screen, press L + R, Left, Up, X, Up, Right, Y, L + R to unlock a bonus level.
At the quest selection screen, press L + R, Down, Up, click the Left Analog-stick, press White, Up, Right, Left, Down, L + R to unlock all quests. If you entered the code correctly, you will hear a sound.
At the character selection screen, press L + R, Down, Up, X, White, Up, X, Black, Up, X, L + R to unlock all duelists.
Successfully complete arcade mode with Volita to unlock Maraxus.
Successfully complete Quest mode using a preset duelist and deck to unlock Mishra.
Successfully complete Arcade Duel mode to unlock Tsabo Tavoc.
Successfully complete arcade mode with Kuldan to unlock Volita.
In arcade duel, when you win with a pre-set duelist on the first level you will unlock a new corresponding color character under him or her. For example, play as Keroc (first black duelist) and win all six fights with him. You will then unlock Mintora or someone to that effect. Win six fights with her and you will be able to play as Ishan's Shade. By playing as pre-set character on arcade mode, you will unlock a new character.
Before playing on Xbox Live, play quest mode first to avoid losing ranks. After doing this, also finish all of arcade duel to unlock new characters. You will then have a lot of characters. Next, make your own deck. Some good decks are Red, Red-White, and Green-Black, but they are difficult to use. Then, go to Xbox Live and always play average opponents. When you play a difficult opponent and win, you might gain up to 500 to 1,000 ranks.. If you are ranked 500 and less, .do not play people that are ranked at 1,000 or higher or you will lose a lot of ranks.