Pokémon Trading Card Game/Fighting Club

The Fighting Club acts as the game's one real "quest", which requires possibly revisiting locations you've already been to accomplish a certain goal. Upon first entering the main area of the Fighting Club, you'll find it strangely empty, with only Leader Mitch in attendance. He tells you the following when you first speak to him, which sets the event flag:

Until you actually defeat all three of his pupils at the clubs listed below, he will continue to repeat the last three lines. Upon defeat each member of the Fighting Club will return, and once all three return you will be able to challenge Mitch.

Much of the advice from the ../Rock Club/ holds true here since Fighting, Rock, and Ground are closely related in this era of the TCG. It's rare that the Fighting Club members are going to be able to exploit your weaknesses unless you're using a Lightning / Colorless deck, and their decks are highly unlikely to feature resistance to most of your deck.

Deck Building Strategy
Flying-type monsters (Pidgey, Pidgeotto, Pigeot, Farfetch'd, Zubat, Golbat, Doduo, Dodrio, etc.) all have resistance to Fighting/Rock/Ground monsters, as you would expect from the type matchups found in Pokémon Red and Blue. One card you may find an oddly effective stall, though, is Gastly Lv. 8 - in spite of how it's a pretty useless card anywhere but here and the Rock Club. While it only has 30 HP, it also resists these attacks for -30 damage. Add to that the fact that Gastly Lv. 8 has the Sleeping Gas attack (Flip a coin - if Heads, the opponent is now Asleep), and you'll be able to stall out most of the Fighting Club's star monsters until you can get enough energy on your Bench to act. Gastly Lv. 17, boasting 20 HP extra and Lick for 10 damage, is more effective at whittling down your opponent. Either version of Haunter will stall, but Lv. 22 can put an opponent to Sleep without a coin flip and then do 50 damage the next turn with Dream Eater. Gengar is a possible choice as well if you think the more reliable Dark Mind — 30 damage to opponent + 10 to one benched monster— and Curse — Move 1 damage counter (10 HP) per turn — is going to be better than risking the opponent passing a Sleep Test to do 50.

Chris
Chris is in the lounge of the ../Rock Club/. He'll return to the main hall of the Fighting Club after defeating him.

The deck he is using is a little unfocused, but the Colorless Pokémon are around to prevent you from sweeping his deck with Psychic Pokémon. Hitmonchan is a big threat. It's a Basic Pokémon with an attack that does 20 damage for a single Fighting energy. If you're not facing it with a Pokémon with Fighting resistance, the damage will add up quickly. It gets even worse once it gets 3 energy—2 Fighting, 1 Colorless—on it and can even hit over the resistance. Hitmonlee isn't quite as threatening, but the damage it does to the bench can add up. Its 3 Fighting energy attack, High Jump Kick, is even stronger than Hitmonchan's. You'll want to take them both out before too much energy ends up in play.

Michael
You'll find Michael in the lobby of the ../Grass Club/. He'll return to the main hall of the Fighting Club after defeating him.

This deck is one of the more competent builds, especially for a Club Member rather than a Club Master. Hitmonchan and Electabuzz can hit for just one energy of the same type as the Pokémon. Hitmonchan's hits hard, and Electabuzz can cause Paralysis. Magmar and Hitmonlee both require two energy the same type as themselves to start attacking. Magmar hits hard, Hitmonlee starts wearing down the bench. If three energy end up on Hitmonlee, Hitmonchan, or Magmar, you're looking at a very difficult to win battle.

Jessica
Jessica is hanging out at the card table in the lounge of the ../Fire Club/. She'll return to the main hall of the Fighting Club after defeating her.

The basic Pokémon in Jessica's deck are pretty easy to take out. The biggest threats are Tauros if you can't knock it out in one hit, and Machop's evolutions. Machoke and Machamp have hefty attack costs though. This is one of the easier decks to win against even early on.

Club Master: Mitch
All members of the Fighting Club must be fought in alternate locations before they will return to the Fighting Club after first speaking to Leader Mitch. Leader Mitch cannot be challenged until this quest is completed.

Coming to the Fighting Club first and speaking to Mitch before you get started on any other medal can save on some backtracking. In a game where you're likely to be grinding to get that one card you want for your deck, this can be a major boon.

Once again, Hitmonchan and Hitmonlee are the biggest threats in this list. Unless you let a Machop evolve and get energy there isn't anything too unique about this deck. It's a more focused Muscles for Brains deck, but that focus also loses its anti-Psychic Colorless Pokémon. You can probably streamline the deck you used in that duel to make it more effective here. You'll want to look out for some of the Trainer cards though. Defender will reduce damage his active Pokémon takes by 20, and PlusPower will add 10 to the damage his active Pokémon does. His Gust of Wind can also inconvenience you by switching a Pokémon not ready to attack nor retreat.

Winning against Mitch will reward you with the Fighting medal.