Yu-Gi-Oh! World Championship Tournament 2004

'Yu-Gi-Oh! World Championship Tournament 2004, known in Japan as Yu-Gi-Oh! Duel Monsters 9: Expert 3' (遊戯王デュエルモンスターズ エキスパート3), is a video game based on the Yu-Gi-Oh! franchise.

The game has been released on the Game Boy Advance. In the game, the player can assemble three decks and can play Duel Monsters against a variety of computer opponents. The game features the first 1,108 cards released in Japan. There are 29 opponents in the game. Each opponent has different skills and decks revolve around a certain theme (Yugi Mutou=Basic, Rare Hunter = Exodia, Yami Yugi = Ultimate, etc.).

The stronger opposing decks (Level Four and above) use three copies of the Forbidden/Limited/Semi-Limited cards. Also, the opponent can switch flip effect monsters into defense the turn they are flip summoned if no other rules restrict it.

Opposing Decks
Level 1 Deck-The only threat in this deck is Goblin Attack Force, which can be easily disposed of after it attacks. All other monsters have under 1000 ATK/DEF, except for Hyozanryu, which would be incredibly hard to summon due to lack of tributes.
 * Tristan

Deck-This deck is also easy to beat due to lack of stall cards, but it would take a long time due to the effective Life Points healing cards. It is possible for Tea to summon St. Joan with her high 2000 DEF Forgiving Maiden and decent 1700 ATK Marie the Fallen One. Other than that, Fire Princess can burn off a massive amount of your Life Points if not disposed of quickly.
 * Tea

Deck-Yugi has a number of cards that control the Monster Card Zones. He has weak monsters, but if you have no monsters, Gemini Elf, Summoned Skull, or Dark Magician will be summoned.
 * Yugi

Deck-This deck is the basically the same as Yugi's except Exodia, Backup Soldier, and Blue-Eyes White Dragon replace Yugi's high ATK monsters.
 * Trusdale

Deck-The only thing dangerous in this deck are the three Maha Vailos and the rarely used Equip Cards.
 * Bakura

Level 2 Deck-This deck is like the ones in Level 1. The strongest monsters are Crawling Dragon and Two-Headed King Rex. No tribute monster has over 2000 ATK, and the Fusion has 2200 ATK.
 * Rex Raptor Unlocked by-

Deck-Weevil has a rather scary deck to duel against, using Mirror Force, Torrential Tribute, and Man-Eater Bug. Sangan can bring out Witch of the Black Forest, which in turn gets Empress Mantis or Jirai Gumo (which is usually already summoned). If you can get past the Traps and ATK power, Raigeki will stop you, though it'll be used once.
 * Weevil Underwood Unlocked by-

Deck-Mako has Umi and A Legendary Ocean, so he can summon The Legendary Fisherman easily and devastate with Amphibian Beast. With Torrential Tribute and Tornado Wall, this deck is very hard to inflict damage on.
 * Mako Tsunami Unlocked by-

Level 3 Deck-Pegasus uses Vorse Raider and Nimble Momonga to fend of attacks, along with the many shielding Traps in order to summon his heavy damaging Toon Monsters. This deck pays a lot of Life Points but also has lots of healing, like Tea. Mirror Wall is often played when it isn't needed to, sometimes resulting in a wasted Trap or a loss if 2000 (sometimes 4000) Life Points. Sometimes, Toon Mermaid will be Special Summoned, and then summon Normal Summoned Skull.
 * Maximillion Pegasus Unlocked by-

Deck-There are few monsters in this deck, though Blocker has high defense to stall to summon Pendulum Machine, Slot Machine, or Barrel Dragon, along with cards like Overdrive, Oni Tank T-34, and Mechanicalchaser for support. There are also six Traps, three Trap Holes and three Gambles.
 * Bandit Keith Unlocked by-

Game Glitches

 * The text on "Dark Sage" mistakenly calls "Dark Magician" "Dark Spellian". This is likely as a result of changing the names of Magic Cards to Spell Cards.
 * You take all the damage from Burning Land.

Limited Edition Cards
The following cards were included in the North American version of this game:
 * WC4-001 Fairy King Truesdale
 * WC4-002 Kinetic Soldier
 * WC4-003 Slate Warrior

The European and Australian versions of this game included the following cards:
 * WC4-E001 Valkyrion the Magna Warrior
 * WC4-E002 Sinister Serpent
 * WC4-E003 Harpie's Feather Duster