Instructions
Beginner's Cup
Duel at nighttime until you are confronted by Yami Yugi. He will talk to you about the dangers of dueling at night.
Check your email the next day for a message from Kaiba Corp warning you not to duel at night. After this note, you will be forced into shadow games by rare hunters randomly at night. Save your game before you go out at night, as losing a shadow game means losing your rarest card.
Defeat Dox and Serenity in a duel. Dox will kidnap Serenity and challenge you to a shadow game duel. You must defeat Dox in this duel to continue.
Travel at night until you randomly encounter Para, who will challenge you to a duel. You must defeat Para in this shadow game duel.
Reach level eight and Mokuba will invite you to the beginner's cup tournament. The next day, Roland will find you and take you to the tournament.
Expert's Cup Tournament
Look for a thief until nighttime. You will eventually run into Yugi and hear a scream. Follow Yugi to the warehouse where Joey is dueling Bandit Keith.
Defeat Bandit Keith in a shadow game.
Talk to Kaiba the next morning. He will upgrade your duel disk so you can see an opponent's star rating before you duel him.
Wait until nighttime and then go out and search for a three-star duelist. The first (and only) duelist you will find will be Bandit Keith, who is disguised. Before you can duel him, Pegasus will interrupt you and challenge you to a shadow game.
Defeat Pegasus to receive the Beginner's Cup booster pack. Kaiba will then appear and invite you to the Expert Cup tournament. Return to your home, and the next morning you will be shown a scene of your character boarding a train to the Expert Cup tournament.