In your journey through the Kanto region, your first stop will be in Pewter City, where you can challenge the Rock-Solid Pokémon Trainer Brock. Brock specializes in Rock-type Pokémon. Here’s everything you need to know to defeat Brock and earn your first badge:

Brock’s Team
Brock uses two Pokémon:
- Geodude (Level 12) – Rock/Ground
- Onix (Level 14) – Rock/Ground

Even though Brock is a Rock-type specialist, both of his Pokémon are also Ground-type. Giving them 4x weakness to Water and Grass.
Onix is Brock’s Ace Pokémon. It is very physically bulky but has low attack. Onix can use Rock Tomb, a 60-power move that lowers your Speed. If you let your Pokémon’s Speed drop, it may cause you to lose the battle, so be careful of that.
Type Matchups
Since both of Brock’s Pokémon are Rock/Ground type, other than the aforementioned Grass and Water quad weakness, they will also be weak to Ground, Fighting, Ice, and Steel types. And will resist Normal, Flying, Rock, Fire, and Poison(x1/4) types while being completely immune to Electric type moves.
Pokémon Tips
If you picked Bulbasaur or Squirtle as your starter, this gym is a piece of cake. But if your starter is Charmander, you may find it difficult to defeat Brock. If you find yourself in this situation, I would suggest catching and using a Mankey, which you can find on Route 22 (West of Viridian City).
Rewards

After defeating Brock, you will be awarded TM39 Rock Tomb and the Boulder Badge.
If you have the Boulder Badge:
- Pokémon up to Level 20 will obey you.
- You can use HM05 Flash outside of battle.
Defeating Brock is the first step in your journey to become the champion of the Kanto region; the difficulty of this fight entirely lies in the Starter you chose. But if you have the correct counters, this fight is a perfect introduction to the Kanto region.


