Brock, the Pewter City Gym Leader, specializes in Rock-type Pokémon. His team consists of a Geodude and an Onix. Grass and Water-type Pokémon (like Bulbasaur or Squirtle) have a significant advantage. If you chose Charmander, consider catching a Mankey on Route 22 (west of Viridian City) or a Nidoran (male or female) on Route 3, as they learn Fighting-type moves. Level up your Pokémon to at least level 12-14 for an easier fight. Defeat him to earn the Boulder Badge and TM39 (Rock Tomb).
