A/N: Okay, here's another of my takes on one of my own challenges. In this, I fuse the world of Harry Potter and Yu-Gi-Oh. I'd explain more, but the first chapters will explain everything.

Scales of Justice

Chapter I: The Game That Changed the World

In 1981, two events happened that would rock the Magical world, a world that had been hidden for more than two centuries out of fear. The second event was the death of the terrorist leader known as the Dark Lord Voldemort due to a ritual performed by Lily Anne Potter nee Evans on her son, Harry James Potter. Lily Potter sacrificed her life in order to save her son, and as a result, when Voldemort cast the infamous Killing Curse at Harry, it backfired, destroying Voldemort, while Harry survived, becoming internationally famous as the Boy-Who-Lived.

The first event happened nearly two months earlier, as a few Muggleborns brought some decks of cards with them on their first trip to Hogwarts on September 1, 1981. Though a mere pebble in the lake of reality compared to the events of the following Halloween, this pebble would create ripples that would shake the very foundations of both the Magical and Mundane worlds.

Alan Foster was wandering the Hogwarts Express, hoping to find a fairly open compartment, or at least one with kids his age in it. To try and calm his nerves, he pulled out his deck of cards and started shuffling them, a habit that he had only recently gained. That was when a voice called out "Hey, is that a Duel Monsters deck in your hands?" Alan turned to the voice and nodded. The speaker was a girl about his age, one with golden hair and the darkest eyes he had ever seen. "Cool! I haven't found any other duellists so far, you want to share my cabin?" Alan jumped at the chance, and within minutes Alan and his new friend, Joanna Martin were duelling each other.

When they arrived at Hogwarts, the duo, who had quickly become best friends were both sorted into Hufflepuff, but it was the following Saturday, September 5 that they shook things up. Joanna and Alan were living up to their House and had already finished their homework for their first week, and that allowed them to spend the weekend having fun. And for them, that meant duelling. "Ready, Jo?" Alan asked.

"Ready, Al." The duo quickly set up in the middle of the Hufflepuff table, and within minutes had gathered a crowd of fellow Muggleborns. By the time their first duel was over, even purebloods were watching.

"So, how do you play?" William Dillane, a pureblood Ravenclaw asked.

"It's a game of strategy, imagination and luck," Alan explained. "The luck of the draw, your strategic use of the cards in your hand, and your inventiveness in combining your cards to make the best attack or defence. Now, there are three types of cards: Monsters, which are your soldiers, Magic cards, which can boost your Monster's strength, and Trap cards, which are self-explanatory." He then held up one of his favourite cards, the Dark Magician. "Now, you see how this card has two numbers on it? The left number is it's attack strength, the right is it's defence strength. You play the monster in Attack or Defence position. If I attack a monster in Attack position with a lower attack number, I win the fight, and the difference in strength is taken from my opponent's life points. However, if the monster is in Defence mode, then only the monster is destroyed, usually. Oh, and on the subject of life points, each player has 2000 life points, and using your cards, you need to eliminate all your opponent's life points. Last one standing wins."

"Strategy comes into play another way," Jo added. "You can own as many cards as you want, but you can only play with a maximum of 60 cards per duel. You need to figure out the best combination of cards in order to win, and to do that, you need to really know your cards and what they can do."

"Wait, what happens if you attack a stronger monster, or if they are the same strength?" Will asked. "I noticed that sometimes you play a card face down, hiding their strength."

"Good question, and that is exactly the reason," Alan replied. "As for what happens, it depends on the target, actually. If the you attack a monster in attack mode and it's stronger, then you lose the life points. If the two are in attack mode and equal, then both monsters die and life points aren't touched. If you attack a stronger monster in defence, both monsters survive, and you lose life points. If the two are equal, then both monsters survive and no life points are lost. Also, another good strategy is to always play your traps face down, that way your opponent doesn't know if you've played a monster, a spell or a trap."

By the end of September, all of Hufflepuff, and most of Gryffindor and Ravenclaw were hooked on the game, especially since the rest of the Muggleborns sent owls home so their parents could send their own decks. After Christmas, the half-bloods and purebloods started playing thanks to their Muggleborn friends. It so exploded in popularity that in Alan and Jo's Third Year, Will Dillane decided to enchant his own deck so that when he played a card, an illusion of the card would show up in front of him. It became so popular that by the end of the year, Will had enchanted every deck in Hogwarts, which by that time had expanded to even conservative Slytherin House. But Slytherin House had added a new dimension to the game: legillimency, a magical art that allowed them to get inside their opponent's heads. To counter that, the art of occlumency was added to the DADA curriculum. The next year, 1985, Will's first year out of Hogwarts, Will opened a game shop, stocked with every game that Muggles had created up to then, though some were changed to better fit the magical world. While the games were all popular, by far the most popular was Duel Monsters.

The ripples might have stopped there, if it weren't for one incident, again including Alan Foster. With the massive increase in experience he was gaining at Hogwarts, and some of the best trades he had ever done, (thanks to the inexperience of the pureblood players,) Alan was easily one of the best duellists in Canterbury. As such, the other local greats often sought him out, and at the first duel, they and their audience learned about the enchantment on the cards. With that one duel, and Alan's ignorance of the Statute of Secrecy, the Statute was broken, for not even the Obliviators could contain it. The duel had been televised, and Alan's competition had been from Southampton, while Alan himself had stated after the duel that his cards had been enchanted. Within hours, the British Prime Minister Margaret Thatcher revealed that magic was real and that a purely magical world existed along side their own, hidden for their own protection. By the next week, every government in the world had passed laws protecting all magicals from any kind of persecution, and preserving their governments, though they were now folded into the muggle, or now as it was called, mundane governments.

By 1987, the transition had been completed, and technological problems solved. The Muggleborns could now take their phones and other electric devices into magical areas and have them still work, and the growing field of genetics had not only found the magical gene, but also what caused squibs to be born. By 1990, not only had they found that out, but with the smaller nations, they had discovered how to find Muggleborns before they were even born, due to the discovery that with squibs, magic was still in them, just dormant. Even the goblins rejoiced at the reunion of the worlds as with genetics, old families whose vaults had lain dormant were being used once again, and with more gold flowing, the goblin's profits grew.

Also by 1987, the young but imaginative Seto Kaiba, the heir to KaibaCorp had come up with a way to duplicate the magical illusions of the cards with technology, and partnering with Maximillion Pegasus had created duelling arenas around the world. Albus Dumbledore, Headmaster of Hogwarts, though conservative had seen the way the wind was blowing, and quickly made Duel Monsters an official sport at Hogwarts, allowing Pegasus and Kaiba to build a duelling arena at Hogwarts, though their own arena would only be used for the semi-finals between the top twenty duellists. Dumbledore's only worry was how Voldemort would react to the radical changes in their world, and whether the peace between the two worlds would last when the mundane world faced the terror that was the Dark Lord Voldemort.

Voldemort on the other hand, despite his long exile without a body, had used the time not only to recover, but to do some more exploration. And his exploration had borne unexpected fruit. He had travelled a bit further south than he had planned and ended up in Egypt, but that was where he learned of an unorthodox archaeologist named Dr Arthur Hawkins. Dr Hawkins described a type of magical fighting called the Shadow Games that could have destroyed the world. Voldemort immediately caught on to the possibility, and by possessing one of the workers, he quickly stole a torque necklace from the tomb that described the Shadow Games, sensing incredible magical power from it. He got another shock when he learned that with it, he could see glimpses of the future, and the past. With the visions of the past, he learned that Dr Hawkins theory was truer than he could have possibly imagined! So, following the prompting of the necklace, Voldemort returned to Albania, and bided his time until Quirinius Quirrell would arrive. Then he would start on the road to his true return, and the Ministry would again tremble at the name of Lord Voldemort!

A/N: Now, I have a question for all of you. Alan is going to be one of the eight finalists in the Duellist Kingdom, and I want to know who you think he should face between Yugi and Joey. I already know how the rest of the Finals is going to turn out, I just need to figure out the last duel. If Alan faces Yugi, then Joey faces Bandit Keith, as in canon.