Up until Pokémon Legends: Arceus’ ancient Pokédex was revealed, it was considered common knowledge amongst Pokémon fans that Professor Oak invented the original Pokédex. Every mainline game in the Pokémon series up to this point has maintained that fact as well, with several other characters supporting Professor Oak’s claim to fame as the Pokédex’s inventor. However, as players join the Survey Corps in Pokémon Legends: Arceus and venture out into Hisui to gather research for the ancient Pokédex, it’s obvious that Professor Oak didn’t actually come up with the concept himself, proving that the most beloved Pokémon Professor wasn’t being entirely honest with players when he first sent them off on their adventures back in Pokémon Red and Green.
Professor Oak appears in many Pokémon games and is one of the most well-known and well-liked characters in the Pokémon franchise. He’s the quintessential Pokémon Professor, dedicated entirely to the research of Pokémon, and he’s inspired trainers to head out into the vast world of Pokémon since the beginning of the franchise. Though he comes across as rather forgetful, even forgetting the name of his own grandson in Red and Green, players haven’t had much reason to doubt his credibility over his iconic invention of the Pokédex before the release of Pokémon Legends: Arceus.
After players literally drop into ancient Hisui, however, it quickly becomes apparent that the Pokédex actually existed long before Professor Oak was even born. When Pokémon Legends: Arceus' Professor Laventon finds the player on Prelude Beach at the beginning of the game, he enlists their help to compile the first Pokédex of the Hisui region, even hinting at possible ancient Pokédexes from other regions as well. It’s clear that the concept of a Pokédex has existed since long before people and Pokémon even became partners, which means Professor Oak’s iconic invention was not the first Pokédex as players have been led to believe.
Why Professor Oak Isn’t As Honest As We Thought
While Professor Oak comes across as a kind and studious mentor when players are introduced to him in Pokémon Red and Green, there’s a lot that many players don’t know about him. Not only is he rumored to be a powerful trainer by other characters in the series like Agatha of the Elite Four, but unused game data in Red and Green revealed that Professor Oak had a team of Champion-level Pokémon and might have originally been a final boss or postgame fight. In the manga, he even battles in disguise as “Dr. O,” proving that there’s a lot more to this prolific Professor than meets the eye.
It’s possible that Professor Oak was simply crediting himself with creating the first electronic version of the Pokémon encyclopedia that players have become familiar with, but Pokémon Legends: Arceus’ ancient Pokédex still retcons this important piece of Pokémon lore. The Pokédex has been a core part of every Pokémon game in the mainline series that evolves as technology gets more advanced with every generation, so it does seem bizarre for one Professor to earn all of the credit for its invention, especially if full Pokédexes have existed since ancient Hisui or earlier in less-advanced books and paper catalogs. Regardless, players still have Professor Oak to thank for the digital database that they fill in every mainline Pokémon game except Pokémon Legends: Arceus, even if he wasn’t honest about how the Pokédex really came to be.