Players jumping into Pokémon Yellow for the very first time may be left wondering why Game Freak disabled the evolution feature for the game's Starter Pokémon Pikachu. The Pokémon franchise originally made its debut in Japan in 1996, before launching worldwide two years later with the Pokémon Red and Blue RPGs. The classic Generation 1 game received a Pok émon Yellow edition in 1999, which many consider the best version of the Kanto region. Newcomers revisiting Red and Blue's third edition may be left confused, though, as Pikachu is unable to evolve even after a Thunder Stone is used on the adorable yellow Pokémon.
Following the release of Red and Blue, the Nintendo franchise became an absolute cultural phenomenon with the launch of the Pokémon anime in 1998. Children around the world became hooked on the adventures of Ash Ketchum and his sidekick Pikachu. The show was so popular, that Game Freak released Pokémon Yellow in 1999 to make the Red and Blue RPGs closer to the animated series. The third edition RPG swapped out many NPCs in the game for characters in the anime and featured location changes to match Ash Ketchum's journey through the Pokémon League. Pokémon Yellow's Starter Pikachu was the biggest change made to the Gen 1 RPG's storyline, as the Electric mouse was now the player's first Partner Pokémon given to them by Professor Oak.
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As a result, players are not actually able to choose a Gen 1 Starter at the beginning of Pokémon Yellow, as Pikachu automatically becomes the user's main Pokémon throughout the story. Although the RPG's main rival is able to evolve his Eevee, players eventually discover that the evolution feature has been disabled for Pikachu. Below is a breakdown of why the Electric-type won't evolve in Pokémon Yellow, and how it's tied to the anime and the series lore.
Pikachu Refuses To Evolve In Pokémon Yellow Because Of The Anime
While Pikachu's evolution Raichu was originally present in Gen 1, it's established in the anime's first season that Ash Ketchum's Partner Pokémon does not want to evolve. The first example of this is in the fourteenth episode "Electric Shock Showdown" which aired in September 1998. In the story, Ash has to face off against Pikachu's Kanto evolution Raichu during a battle with Lt. Surge. In the story arc, Pikachu decides to not evolve with Ketchum's Thunder Stone, as it would rather face and defeat Raichu on its own terms. Following the episode, Pikachu refusing to evolve became a recurring plot point throughout the animated series' twenty-three seasons.
Because Pokémon Yellow is designed to replicate the first season of the anime, Game Freak changed the game so that players' Starter Pikachu will also reject its evolution. Players who attempt to give the mouse Pokémon a Thunder Stone will actually trigger an Easter Egg with Pikachu yelling through the Game Boy speakers and frowning. Although the evolution mechanic being disabled may be confusing for new players trying out the game years after its release, it's a really neat feature that makes the RPG feel more authentic to the animated series. The Pokémon Journeys: The Series anime even covered the topic in a 2020 episode where Ash Ketchum proudly declares that Pokémon should be able to evolve at their own pace. Netflix posted a clip of the iconic scene on their official "After School" YouTube account, which shows Pikachu rejecting a Thunder Stone from another Pikachu.
Pikachu rejecting its evolution isn't the only unique quirk the Electric-type Pokémon has in the anime, as it also refuses to go inside of its own Poké Ball. This is why the Starter Pokémon follows the player around in Pokémon Yellow. Although the 1999 title was largely just a remake of Red and Blue, Game Freak went to great lengths to try to bring anime viewers into their RPG franchise as well by making the game as similar to the television series as possible.
Source: Netflix/YouTube
