In the Game there are two options - one of them is "Duel World". In this mode, the player travel through the different worlds as the player complete events and unlock duelists and packs.
The world of grace is a nice peaceful area where the player starts in. Have a look around and the player will see.
- A Colosseum
- A tent
- A spring with ripples in it.
- Some duel spirits
The Colosseum is the Structure Deck Colosseum, where the player will have to face Amazoness Paladin using one of the thirteen structure decks. Amazoness Paladin will also be dueling the player using a randomly chosen structure deck as well.
- The structure decks are:
Defeat her using all decks to unlock Bastion Misawa in World Championship Mode, get the Amazoness Duel Disk in the wardrobe and get the Amazoness card set.
The tent is where the player can pay 50DP to get a fortune - this fortune can help the player proceed through the Duel World storyline if the player gets stuck.
There are also some Duel Spirits against whom the player can duel in this world:
- Skull Servant (unlocks King of the Skull Servants)
- Nightmare Penguin (unlocks Reaper on the Nightmare)
- Elemental Hero Knospe (unlocks Elemental Hero Lady Heat)
- Sonic Shooter (unlocks Silpheed)
- Kairyu-Shin (Found in the lake, unlocks Water Dragon)
Defeat each duelist 5 times to unlock their respective duelist in World Championship Mode.
Once the player have beat everyone at least once, the player will see a Curse of Vampire bullying Gigobyte. Talk to Gigobyte, and Vampire's Curse will intervene. If the player wager a rare card, he will agree to duel the player.
Defeat him, and the player unlock Vampire's Curse in World Championship Mode, and Gigobyte will show the player to the gate.
Green Guardian - Embust will present the player with 5 different decks to duel against. Beat 3, and he will open the gate, allowing the player to enter the next world - World of Sunlight.
Defeat all 5 decks to unlock Syrus Truesdale in World Championship Mode.
If the player returns afterwards, the player will sometimes see White Magician Pikeru - she'll ask for a cute card. Give her one, and she will disappear, and there may be a chance that Ebon Magician Curran will appear to duel. After beating her, she will disappear - the player will have to give Pikeru another card to restart the process.
Beat Curran 5 times to unlock Dark Magician Girl and give Pikeru 5 different cute cards to unlock her in World Championship Mode.
There's also a stone monument here, once the player has done all this - to unseal it, the player need to summon Master of Oz and win the duel. For this effort, the player unlock Tyranno Hassleberry in World Championship Mode.
In this world, the player will see a Pyramid with Guardian Sphinx beside it. Talk to him and the player will be presented with 5 Duel Puzzles. Complete 3 to enter the pyramid, complete 5 to unlock Maximillion Pegasus in World Championship Mode.
Also, outside there are other duelists. Beating them 5 times unlocks their respective duelist in World Championship Mode.
- Warrior Lady of the Wasteland (unlocks D.D. Warrior Lady)
- Kabazauls (unlocks Sabersaurus)
- Mech Bass (found in the water when ripples appear, unlocks nothing)
- The Legendary Fisherman (found in the water when ripples appear, unlocks nothing)
Defeating both Warrior Lady and Kabazauls 5 times each unlocks another stone monument - this one requires the player to summon Exxod, Master of The Guard and win. Do this and unlock Marcel in World Championship Mode.
Inside the pyramid there are even more duelists.
- Gravekeeper's Commandant (unlocks Gravekeeper's Chief)
- Dark Dust Spirit (unlocks Hino-Kagu-Tsuchi)
- Don Zaloog (unlocks Dark Scorpion - Meanae the Thorn )
- Dark Mimic LV1 (unlocks nothing)
Beat each duelist (not counting Dark Mimic LV1) at least once and Spirit of the Pharaoh will appear. Defeat him, and the player unlock Spirit of the Pharaoh in World Championship Mode.
Head outside, and the player will find Sand Moth kicking sand on Pyramid Turtle. Opt to help, and the player will duel Sand Moth. After defeating it, the player unlock Sand Moth in World Championship Mode, and the turtle shows the player to an underwater area.
Here, there are even more duelists.
- Maiden of the Aqua (unlocks Aquarian Alessa)
- Abyss Soldier (unlocks Chrysalis Dolphin)
- Sea Serpent Warrior of Darkness (unlocks Kaiser Sea Horse)
Beat them all at least once and a fourth duelist will appear, Otohime. Defeating them 5 times each brings in another monument that requires Ocean Dragon Lord - Neo-Daedalus. Beating the monument will unlock Atticus Rhodes in World Championship Mode.
Defeat Otohime, and the player unlock her in World Championship Mode, and a new gate will appear.
Shell Guardian - Savan provides the player with 5 challenges. They are all normal duels, but with restrictions to deck building:
- 40 card deck
- 2000 LP
- Only Monster Cards
- Spells Forbidden
- 3 of each card
Complete 3 challenges to unlock the World of Civilization, and complete all 5 to unlock Alexis Rhodes in World Championship Mode.
Once again, some duelists.
- Great Angus (unlocks Vortex Kong)
- Fox Fire (unlocks Molten Zombie)
- Luster Dragon (unlocks Luster Dragon #2)
- Stronghold the Moving Fortress (unlocks Gear Golem the Moving Fortress)
And The Unhappy Maiden is in need of help. Give her 4000 Life Points' worth of LP recovery cards and she will give the player the The Unhappy Girl and The Unhappy Maiden cards. She is also unlocked as an opponent in World Championship Mode.
If the player does chance upon Molten Behemoth, it'll wager a card and request that the player duel for it. Win, and the player will get his offered card.
After beating each duelist (not including Molten Behemoth) once, head back to the World of Grace and talk to Ojama Black. Then, go to the pyramid in the World of Sunlight and talk to Ojama Green - he'll duel the player. Win or lose, head back to the World of Civilization to find Ojama Yellow being attacked by Blowback Dragon. Duel it and win.
For the effort, the player unlock Ojama Yellow and Blowback Dragon in World Championship Mode. Kozaky will also invite the player to his lab. There, the player must duel and beat Inpachi, Blazing Inpachi, and Woodborg Inpachi once each. This unlocks Woodborg Inpachi in World Championship Mode.
Kozaky then asks the player for a favour - to enter the cave in the volcano and find its treasure. Inside await three more duel spirits.
- Volcanic Slicer (unlocks Volcanic Doomfire)
- Blazewing Butterfly (unlocks Il Blud)
- Spirit of the Six Samurai (unlocks Great Shogun Shien)
After defeating each duelist (not counting Kotetsu) once, the player receive the treasure - Limiter Removal. Take it to Kozaky, and he'll work on his new creation, Giga Gagagigo, though it goes out of control. Duel it, and the player will unlock Kozaky in World Championship Mode and find the gate to the next world.
At the gate, the player will be challenged by Speed Guardian - Ferrario. The player have to beat him three times in a row without resting in between, and the player can only carry a maximum of 10000 LP over to the next duels. Defeat him, and the player travel to the World of Darkness, along with unlocking several items at one go - that includes the Axel Brodie Disk and Axel Brodie in World Championship Mode.
This world introduces the player to Tag Duels. Neo-Spacian Dark Panther will explain the mechanics of a tag duel to the player and also puts the player in a practice duel to demonstrate. After this, he'll become the player's tag partner (this can be changed if the player has beaten any duel spirit at least 10 times. Any duel ghost the player has downloaded will also work).
Now, this place has several teams waiting for the player. Defeating each of them 5 times will unlock the respective team in the newly added "Tag Duel" mode in World Championship Mode.
- Mythical Beast Cerberus and Darkblaze Dragon (unlocks Decoy Dragon and Different Dimension Dragon)
- Goe Goe the Gallant Ninja and Lady Ninja Yae (unlocks Sasuke Samurai and Sasuke Samurai #2)
- Vanity's Fiend and Vanity's Ruler (unlocks Machine King and Perfect Machine King)
- Dark Mimic LV3 (Gets the player in a 1v1 duel against it. Unlocks nothing.)
There's Renge, Gatekeeper of Dark World waiting at a corner. Talk to him, and the player has to Tag Duel with some Dark World denizens. Each duel needs the player to wager a "Dark World" card too. The teams are:
- Kahkki, Guerilla of Dark World and Zure, Knight of Dark World
- Goldd, Wu-Lord of Dark World and Sillva, Warlord of Dark World
- Brron, Mad King of Dark World and Reign-Beaux, Overlord of Dark World (defeating this team unlocks themselves in Tag Duel mode)
Also, since the player is wagering a card, the player well also get a Dark World card each time the player defeat a team. Now, once the player is done beating these three teams, duel every team available once more (appears that they have been brainwashed), and then a castle will appear. Visit it, and the player will be greeted by Gogiga Gagagigo and Mobius the Frost Monarch. Beat them, and the player will afterwards be challenged by Vampire Lord and Vampire Lady. Defeat both teams and they unlock themselves in World Championship Mode.
Alien Infiltrator arrives, grumbles about the player undoing of the brainwashing, and disappears into the sky. The map has expanded - the player head up into the skies and take on more teams.
- Harpie Queen and Harpie Girl (unlocks Harpie Lady 1 and Harpie Lady 2)
- Metal Shooter and Satellite Cannon (unlocks Adhesive Explosive and Blast Sphere)
- Lich Lord, King of the Underworld and Alien Hypno (unlocks Alien Mars and Alien Psychic)
UFOroid also appears on occasion. Correctly guess the symbol it is thinking of and it well give the player a card.
Nurse Reficule the Fallen One will be there too, and she may randomly change the appearance of the player's face for 500 DP (The player itself cannot change the result).
After beating each team once, Alien Infiltrator and Alien Shocktrooper will challenge the player to a brainwashing duel - this one is completely computer-controlled. It may take the player a few tries to beat them. After the player beats them, they unlock themselves, and reveal the gate to the next world.
Once again, the player has to face the guardians, Dark World Guardian - Gigori and Underworld Guardian - Moley, and their five deck combinations. Beat three to proceed, and beat five to unlock Aster Phoenix in World Championship Mode.
The World of Order is filled with various challenges that require the player to meet certain conditions to pass. The player must be prepared to stock up on DP to get the right cards and meet these requirements.
As usual, some duelists await the player at first.
- Thunder Nyan Nyan (unlocks Injection Fairy Lily)
- Absorbing Kid from the Sky (unlocks Marie the Fallen One)
Soul of Purity and Light will, like Molten Behemoth in the World of Civilization, offer the player a card if the player manage to duel and win.
Kaibaman also appears here if the player have made a deck with Blue-Eyes White Dragon in it, and requests that the player to summon the monster and beat him. Do so, and the player unlock the real Kaiba in World Championship Mode.
Layard the Liberator guards the gate, and the player well have to beat it using a deck consisting of Fairy-Type monsters. Do this, and it'll expand the map, and Gellenduo will come by talking about a card they lost. Anyway, the player well find a couple more duelists in the area.
Talk to both Nyan Nyan and Absorbing Kid, and they will mention a strangely coloured cloud. A new duelist, Cloudian - Poison Cloud will appear over the hole in the clouds. Beat it, and the player can travel beneath the clouds to find more duelists.
When the player first duels these duelists, the player will be faced with certain conditions.
- Mokey Mokey - 80 card deck (unlocks Petit Dragon)
- Dancing Fairy - Start at 1000 LP (unlocks Gemini Elf)
- Senju of the Thousand Hands - Must win in 5 turns (unlocks Manju of the Ten Thousand Hands)
After beating every duelist here at least once, challenge Senju again he'll say he picked something up, but will only give it to the player if the player beat him in 5 turns. The player's reward is the Nova Summoner card that Gellenduo has dropped.
Go back out, and Radiant Jeral is waiting at the next gate - the player well have to deck it out to win.
After the player is done, it opens the gate - up ahead is Airknight Parshath (character), and a couple more duelists:
Talk to Parshath and give him the Nova Summoner card, but he claims that the player stole it. The player will end up in a duel against Voltanis the Adjudicator.
Win or lose, the player will still be declared guilty until Gellenduo comes in and helps the player out. The player will be proven innocent, and are released. If the player won the duel, the player will unlock both Voltanis and Parshath in World Championship Mode.
Up ahead at the next gate is Harvest Angel of Wisdom, requesting that the player finish him off by doing at least 8000 Life Points' worth of damage in a single turn. Do so, and the next part of the map will be available to the player.
At this point, if the player beat every regular duelist 5 times, the player will unlock a stone monument requiring Rainbow Dragon to be summoned. Beating this will get the player Jesse Anderson in World Championship Mode. Card Trader will also show up, and he does exactly as his name suggests - give him a card, and he'll return the player a random card.
Meltiel, Sage of the Sky will approach the player and congratulate the player for making it this far, and states that there is a gate on top of the tower. However, to reach it the player will have to face several duelists along the way, each with their own condition to meet:
- Alkana Knight Joker - Activate 10 Spells
- The End of Anubis - Activate 10 Traps
- Arcana Force Extra - The Light Ruler - Win with 5 or less cards in the deck
- White Night Dragon - Make it discard 10 cards
- Beast King Barbaros - Make a Chain of at least 5 links
Once the player has beaten all five challenges, the gate awaits the player. Sky Guardian - Sefolile will challenge the player to a 5-round survival duel. Just like Ferrario's, but longer. After the player finishes this, the credits roll, and the player unlocks several things at once, including Dark Zane in World Championship Mode, and the last world - the World of Chaos.
Several duelists await the player, as usual.
- Evil Hero Malicious Edge (unlocks Evil Hero Infernal Gainer)
- Destiny Hero - Plasma (unlocks Destiny Hero - Disk Commander)
- Elemental Hero Neos Alius (unlocks Neo Space Pathfinder)
- Cyber End Dragon (unlocks Cyberdark Dragon)
- Green Gadget (unlocks Ancient Gear Gadjiltron Dragon)
- Horus the Black Flame Dragon LV8 (unlocks Sacred Phoenix of Nephthys)
Beating each duelist 5 times in each of the portions of the map will unlock the 2 last stone monuments.
And this wraps up what awaits within the Duel Worlds.
The player must beat everyone in CPU 5 times in order to get more packs and beat all tournaments 5 times. Make the stone monuments come up in every world and the player gets more packs.