1. While the anime tends to focus upon the game Duel Monsters it took a while for it to show up in the manga, as the story focused upon other kinds of puzzles, riddles, and games.
Even in the first issue, the Pharaoh challenges a bully to a game where the rules are as follows:
Each player takes turns putting a stash of money on top of their hand and stabling through the money with the knife.
Each turn a player must take more than one bill.
The game continues until all the money is gone, and players keep any money they stabbed.
If a player stabs their hand, they lose the game and also forfeit their money.
2. In the anime the makers of the series have promoted other games. Dungeon Dice Monsters is a game that was promoted through the introduction of a character who is the ‘creator’ of Dungeon Dice Monsters. He wants revenge against Yugi, and challenges Yugi to play his game.
In the anime the game features across four episodes called ‘Dungeon Dice Monsters, Part 1’ through to ‘Dungeon Dice Monsters, Part 4’ in season 1.
3. Slifer the Sky Dragon in the Japanese version of the series was called ‘Orsiris.’ The reason for this change between the sub and dub is that Slifer was named after Roger Slifer, who was a 4Kids Entertainment employee, and one of the producers for the anime in the US, at the time.
Here he explains why the card was renamed:
“Another 4Kids employee, Sam Murakami, was our liaison with the producer of the cards. Some names of the cards had to be changed because there was concern their names would be considered demonic or sacrilegious or something here in the states. It never made much sense to me, but when you’re broadcasting here in America, it’s something that has to be accommodated. Anyway, Sam renamed a bunch of those characters after people on staff at 4Kids. It just so happened that the one he named after me happened to be a “god” card and much more prominent than the others in the series. I attribute it to the cosmic forces in the universe trying to balance things for me being made a demon in Ghost Rider. And again, just to set the record straight, I wasn’t even aware of it until after the names on the cards had been changed and it was too late to go back.”
4. There is actually another anime that was produced before the Yu-Gi-Oh! we know today. This anime has been referred to as ‘season zero’ by fans. ‘Season zero’ followed the story of the manga, where the Pharaoh was a much darker character and where the games were a lot more violent.
5. Yugi’s title as the King of Games actually comes from his mastery of all Shadow Games, not just Duel Monsters.