Vermilion Gym appears in all games set in the Kanto region, appearing much the same in each: the main room is filled with 15 trash cans, and Trainers are scattered about this room. Beyond this room is another, guarded by electric doors in Generation I, and an electric fence in Generation III and Generation IV. The only way to get in the final room, where Lt. Surge is located, is to find two hidden switches underneath the trash cans. If the first switch is found, but the player incorrectly guesses the second one, the traps reset. In Generations III and IV, the second switch is always located next to the first. In Generation VII, the switches are always located in the centermost trash can and the can directly north of it. In Generation II, these traps are not turned on.
Vermilion Gym's only anime appearance was in Electric Shock Showdown. Its appearance is similar to a warehouse with lightning bolts painted on it, and the arena inside is a dimly-lit boxing ring. The battles are one on one. One significant difference from the games is that Lt. Surge was shown to have junior Trainers that are both male and female, and wearing military-style uniforms. In the games, his junior Trainers are all male, and none of them wear military-style uniforms.
Ash challenged Lt. Surge to a battle, hoping to acquire his third Badge. However, Surge just laughed when he saw Ash's Pikachu, claiming it could never beat his Raichu. Pikachu decided to prove Surge wrong, and went ahead in battling it. However, its evolved form proved to be much more powerful, and it easily defeated Pikachu.
After doing some training, Ash and Pikachu returned to the Gym. Surge once again felt that the battle was hopeless. What he didn't know was that in between the battles, Ash had taught Pikachu how to use Quick Attack and Agility. This gave Pikachu the advantage, allowing Ash to win the match. Afterwards, Surge gave Ash his Badge, conceding that Ash knew what he was doing.
The Vermilion Gym appeared in Vermilion City, where Satoshi challenged Lt. Surge. The Gym battle was conducted between Satoshi's Charmeleon and Lt. Surge's Electabuzz. Even though Charmeleon was driven into a corner, it was able to use a piece of the barbed-wire fence surrounding the arena to tie Electabuzz up and then finish it off with a Fire-type attack. After the battle, Satoshi received a Thunder Badge from Lt. Surge and an HM01 (Cut) from the captain of the S.S. Anne, whom he had met earlier and was friends with Lt. Surge.
In the TCG
The Vermilion Gym was featured in the TCG as both a Japan-exclusive Theme Deck and as a card. The following is a list of cards named Vermilion City Gym.
Related cards Cards listed with a blue background are only legal to use in the current Expanded format. Cards listed with a silver background are legal to use in both the current Standard and Expanded formats.
In the English versions of Pokémon FireRed and LeafGreen, the Gym guide mistakenly refers to the Flying type as the Bird type. This is likely an oversight derived from his dialogue in the English versions of the Generation I games, where he instead refers to Flying-type Pokémon by describing them as "bird Pokémon"; in the Japanese versions of the Generation I games and FireRed and LeafGreen, he clearly mentions types and correctly identifies the Flying type as ひこうタイプ (the Bird type is とりタイプ in Japanese).
As indicated by a Trainer's dialog, the second switch was apparently intended to always appear next to the first switch in Generation I as well. However, several bugs cause unintended behavior.
Seven of the fifteen cans cannot contain the first switch.
The top-left can has a chance to contain the second switch, regardless of where the first switch was (a 50% chance if the can with the first switch has two or four neighboring cans, and a 25% chance if it has three).
If the can with the first switch has two or four neighboring cans, all but one of its neighbors can never contain the second switch.
Except for the top-left can, no switch that can contain a first switch can contain a second switch, and vice versa.
The can in the middle of the left row cannot contain any switch.