So, you're here. I'm Brock. I'm Pewter's Gym Leader. My rock-hard willpower is evident even in my Pokémon. My Pokémon are all rock hard, and have true-grit determination. That's right - my Pokémon are all the Rock type! Fuhaha! You're going to challenge me knowing that you'll lose? That's the Trainer's honor that compels you to challenge me. Fine, then! Show me your best!

I took you for granted, and so I lost. As proof of your victory, I confer on you this...the official Pokémon League Boulder Badge. Just having the Boulder Badge makes your Pokémon more powerful. It also enables the use of the move Flash outside of battle. Of course, a Pokémon must know the move Flash to use it.

Wait! Take this with you. A TM, Technical Machine, contains a technique for Pokémon. Using a TM teaches the move it contains to a Pokémon. A TM is only good for one use. So, when you use one, pick the Pokémon carefully. Anyways... TM39 contains Rock Tomb. It hurls boulders at the foe and lowers its speed. There are all kind of Trainers in this huge world of ours. You appear to be very gifted as a Pokémon Trainer. So let me make a suggestion. Go to the Gym in Cerulean and test your abilities.