Password mode:
On every Duel Monsters card is an eight-digit password on the lower left corner directly below the card's picture. Enter this code at the "Password" option on the main screen, and the card will be recorded into your card collection. Note: You can only enter the password once.
Information in this section was contributed by Heefcoast247 and BIGTPLAYA.

Information in this section was contributed by M0gster, BIGTPLAYA, RapidRacer2, cody, Rex20xl, ArmandojrBecky, BARPARD, MarvinDouma, RKB22NOW, and kimp.

Left Arm: 07902349
Left Leg: 44519536
Right Arm: 70903634
Right Leg: 08124921
Head: 33396948

Ultimate Exodia:
Sacrifice three Exodias (all the parts) to make Ultimate Exodia (X000,X000).
Information in this section was contributed by RKB22NOW.

Yugi's Grandpa:
Enter 65437205 as a password. Every time you defeat a duelist, Yugi's Grandpa will give you one powerful Magic or Trap (sometimes Monster) card in addition to the normal battle prizes.
Information in this section was contributed by andy wilson.

Yami Yugi:
Enter 70715281 as a password after the game has been completed.
Information in this section was contributed by andy wilson.

Yami Bakura:
Enter 07119986 as a password after the game has been completed.
Information in this section was contributed by andy wilson.

Nitemare:
Enter 43504084 as a password after the game has been completed.
Information in this section was contributed by andy wilson.

Shadi:
Enter 70592699 as a password after the game has been completed.
Information in this section was contributed by andy wilson.

Marik:
Enter 06987398 as a password after the game has been completed.
Information in this section was contributed by andy wilson.

Make your own card:
Enter 45632881 as a password.
Information in this section was contributed by RapidRacer2.

View credits:
Enter 42382443 as a password. Note: You may first need to complete the game.
Information in this section was contributed by Keith.

Card codes:
On the bottom left corner of any Yu-Gi-Oh Trading Card is an eight digit code. Enter this code as a password and you will obtain that card.
Information in this section was contributed by beaches7.

Hint: Gate Guardian:
Get Thunder Sanga, Hyuga of the Wind, and Suga of the Sea. Then, put all of them into your deck. Next, get into a battle. While in battle put Thunder Sanga, Hyuga of the Wind, and Suga of the Sea on the field. After that, sacrifice all of them. If you followed the steps correctly you should summon Gate Guardian.
Information in this section was contributed by Nathan Schumacher.

Hint: Marik:
Marik will try to summon for his Zera card (2800/2600). He has three Swords Of Revealing Light, three Change Of Heart, and three Raigieki, It would be a good idea to have some Anti-Raigiekis.
Information in this section was contributed by zandl.

Hint: Red Eyes Black Metal Dragon:
You must have the Red Eyes Black Dragon and Metalmorph cards in your deck. Put Red Eyes Black Dragon in play. Then, play Metal Morph on him. That should make Red Eyes Black Metal Dragon.
Information in this section was contributed by SurgeStormammc.

Hint: Automatic win:
Get all five parts of Exodia into your hand to win a duel.
Information in this section was contributed by fullerlock.

Hint: Defeating the five Exodia cards:
Get a Blue-Eyes Ultimate Dragon on the field. Use two Castle Of Light or two Spellbinding Circle cards, then attack.
Information in this section was contributed by jslbweb1.

Play two monsters, then play 2 Pronged Attack on one of them. If they play Exodia, activate 2 Pronged Attack, sacrifice your monsters an get rid of one of there pieces of Exodia.
Information in this section was contributed by alex.

Hint: Defeating Darknite:
Play Mechanicalchacer (07359741). He will keep playing Guardian Of Thunder and Protector Of The Throne. The Manchanicalchacer's Atk is 1850, and can defeat anyone.
Information in this section was contributed by RKB22NOW.

To defeat Darknite, you have to have a Stain Storm and a Cursebreaker. Use the Stain Storm when he sends out his Guardian Of Thunder. Use Cursebreaker when he uses Swords Of Revealing Light and Change Of Heart.
Information in this section was contributed by RKB22NOW.

Hint: Duel Monsters fusions:
To merge Duel Monsters, place one of the cards listed below on the board, then place the other card on top of it.
Information in this section was contributed by EvilMajinVegeta , drunken devil, yugi motto, KingofSpaids, Noe Flores, fullerlock, SurgeStormammc, pugman26, alexrocksworlds, BOOKBOY1189, GORDON TENNIS, and Randy Vinci.

Yamatano Dragon Scroll + Shadow Specter = Koumori Dragon
Yamatano Dragon Scroll + Bone Mouse = Koumori Dragon
Yamatano Dragon Scroll + Hiro's Shadow Scouter = Koumori Dragon
Shadow Specter + Masked Clown= Zombie Warrior
Shadow Specter + Boo Koo = Magical Ghost
Bone Mouse + Boo Koo = Magical Ghost
Abyss Flower + Masked Clown = Bean Soldier
Turu-Purun + Kaminarikozou = Bolt Escargot
Muka Muka + Mecha Mole Zombie = Stone Ghost
Kami + Boo Kooo = Immortal of Thunder
Masked Cown + Milus Radiant = Tiger Axe
Jinzo #7 + Masked Clown = Cyber Soldier
Boo koo + Yamatano Dragon Scroll = Lord Of D.
Mystical Elf + Vishwar Randi = Celtic Guardian
Mystical Elf + Wretched Ghost = Dark Elf
Cyber Stein + Yamatano Scroll = Koumori Dragon
Mystical Elf + Shadow Specter = Magical Ghost
White Dolphin + Mechanical Spider = Misainus
White Dolphin + Jinzo #7 = Misairuzame
White Dolphin + Mech Mole = Corroding Shark
Rock Ogre Grotto#1 + Magician Of Farith = Mystical Sand
Y.D. Scroll + Frog The Jam = Spike Seadra
Spike Seadra + Boo Koo = Kiminari Attack
M-Warrior #2 + Bladefly = Cockroach Knight
M-Warrior #2 + Wings Of Wicked Flame = Charucin The Fire
M-Warrior #2 + Petit Dragon = Dragon Statue
M-Warrior #2 + Burglar = Tiger Axe
M-Warrior #2 + Gale Dogra = Cockroach Knight
M-Warrior #2 + White Dolphin = Wow Warrior
Petit Dragon + Genin = Lord Of The D.
Lord Of The D. + Elect. Snake = Immortal Of Thunder
Winged Dragon #1 + Elect. Snake = Thunder Dragon
Gale Dogra + Green Kappa = Cockroach Knight
Celtic Guardian + Trap Master = Dark Elf
Kuriboh + Mystical Elf = Dark Elf
Summoned Skull + Red Eyes Black Dragon = Black Skull Dragon
Fierce Knight + Curse Of Dargon = Gaia The Dragon Champion
Darkworld Thorns + Silver Fang = Flower Wolf (Attack:1800, Defense:1400)
Silver Fang + Flame Manipulator = Flame Cerebus
Battle Ox + Mystic Horseman = Rabid Horseman
Baby Dragon + Time Wizard = Thousand Dragon
Gaia The Feirce Knight + Curse Of Dragon = Gaia The Dragon Champion
Big Shield + Komouri Draogn = Sword Arm Of Dragon
Masaki The Legendary Swordsman + Flame Manipulator = Flame Swordsman
Fire Kraken + Celtic Guardian = Flame Swordsman
Lord of D. + Harpie Lady = Harpie's Pet Dragon
Takriminos + Harpie Lady = Harpie's Pet Dragon
Fire Kraken + Sonic Maid = Flame Swordsman
Celtic Guardian + Kuriboh = Dark Elf
Lord of D. + Giant Rock Soldier = Stone D.
Abyss Flower + Wood Remains = Pumpking the King
Swordsman from a Far + Milus Radiant = Tiger Axe
Swordsman from a Far + Takriminos = Sword Arm of Dragon
Celtic Guardian + Sonic Maid = Musician King
Shadow Specter + Swordsman From A Far = Zombie Warrior
Kaminarikozu + Ancient Sorcerer = The Immortal of Thunder
Dragon Zombie + Gorgon Egg = Ryu-Ra
Cyber Stein + Swordsman From A Far = Cyber Soldier
Boo Koo + Droli Bird = Spirit of The Book
Abyss Flower + Sinister Serpent = Snakeyashi
Frog the Jam + Oscillo Hero #2 = Bolt Escargo
Fusionist + Great White = Marine Beast
Mammoth Graveyard + Cyber-Stein = Cyber Saurus

Hint: Weaknesses:
Information in this section was contributed by Michael Hooks.

Wind defeats Earth
Earth defeats Thunder
Thunder defeats Aqua
Aqua defeats Pyro
Pyro defeats Forest
Forest defeats Wind
Shadow defeats Light
Light beat Fiend
Fiend defeats Dream
Dream defeats Shadow

Hint: Saving card values:
Instead of wasting six cards to use BEUD or Gate Guardian, if your duelist level is at 255, just put them in your deck and get rid of two cards instead of six.

Hint: Powered-up cards:
Some cards are changed and are better. For example, the level is still the same for Castle Of Dark Illusions and Castle Of Dark Magic. except Castle Of Dark Magic has 2500 defense and a effect (flip over all monsters on the field). Also, the King Of Yamimakai has 2600 attack instead of 2000.
Information in this section was contributed by NoobSaiboTX