Pewter Gym · Gym 1
How to beat Brock in Pokemon Yellow
Brock is the classic Yellow roadblock because partner Pikachu cannot damage his Rock/Ground pair. Beat him with Fighting, Water, Grass, or Special damage—not Thunder Shock. His Yellow team is Geodude Lv.10 and Onix Lv.12.
Fast Answer
Do not use Electric moves
Catch Mankey on Route 22 and teach it Low Kick at Lv.9, or raise Nidoran♂ to Lv.12 for Double Kick, or evolve a Viridian Forest Caterpie into Butterfree for Confusion. Fight recommended around party levels 10–14. Onix can use Bind and Bide—switch or wait out Bide instead of attacking blindly.
Why Brock feels unfair
Why is Brock so hard in Pokemon Yellow?
Red and Blue often start with Squirtle or Bulbasaur, which beat Rock types easily. Yellow gives you partner Pikachu. Both of Brock’s Pokemon are Rock/Ground, so Electric moves deal zero damage—you need a different answer before Pewter Gym.
Pewter Gym fight
Brock’s Pewter Gym team
Brock uses Geodude Lv.10 and Onix Lv.12. The gym Jr. Trainer has Diglett Lv.9 and Sandshrew Lv.9—also Ground-types, so skip Electric there too.
Slot 1
Geodude · Lv.10
- Moves: Tackle
- Threat: High Defense; physical chips feel slow
- Answer: Fighting / Water / Grass / Special
Slot 2
Onix · Lv.12
- Moves: Screech, Tackle, Bind, Bide
- Threat: Bind stalls; Bide doubles stored damage
- Answer: Super-effective hits; wait out Bide turns
4× weaknesses
Rock/Ground takes 4× damage from Water and Grass. Fighting is 2×. Special moves also bypass their massive Defense into a weak Special stat.
Gym layout
No switch puzzle. You can walk around the Jr. Trainer or beat Diglett/Sandshrew for experience before Brock.
Rewards
Boulder Badge raises Attack in battle and enables Flash outside battle. Brock also gives TM34 Bide.
Checklist
Prep, fight, badge
Checks save on this device so you can resume later.
Path A · Fighting
Mankey — best no-Nidoran answer
Route 22 grass · Low Kick at Lv.9
Available before Pewter. Low Kick hits both Geodude and Onix super effectively. This is the cleanest answer when you skip Nidoran entirely.
- Catch: Route 22 (west of Viridian)
- Key move: Low Kick · Lv.9
- Also: Route 3 Mankey if you missed Route 22
Path B · Poison
Nidoran♂ — Double Kick route
Route 22 / Route 2 · Double Kick at Lv.12
In Yellow, Nidoran♂ learns Double Kick at level 12. Raise him to 12 before the gym so the Fighting move is ready. Skip this mon if you already have Mankey or Butterfree.
- Catch: Route 22 (common) or Route 2
- Key move: Double Kick · Lv.12
- Note: Level to 12 before Brock for the move
Path C · Bug / Flying
Butterfree — Special path
Viridian Forest · Confusion + optional Stun Spore
Evolve Caterpie → Metapod → Butterfree. Confusion targets Brock’s low Special. Optional Stun Spore at Lv.14 makes Onix safer to finish.
- Catch: Caterpie / Metapod in Viridian Forest
- Key move: Confusion on evolution
- Bonus: Stun Spore Lv.14 setup
Team-limited runs
Pokemon Yellow Brock without Nidoran
You do not need Nidoran♂. Prefer Mankey + Low Kick if you can reach Route 22, or grind the Caterpie line in Viridian Forest for Butterfree. Both counters are available before Pewter.
- Detour to Route 22 for Mankey (or farm Caterpie in the forest).
- Level until Low Kick or Confusion is online; heal in Pewter.
- Open the Pewter Gym tool, then finish Geodude and Onix.
In battle
In-battle plan
- Use Fighting, Water, or Grass damage; Brock’s Rock/Ground pair takes 4× from Water and Grass.
- Special attacks work around Geodude and Onix’s high Defense and very low Special.
- Onix can lock a slower Pokemon with Bind and punish damage with Bide—avoid attacking blindly into Bide turns.
After the badge
What unlocks next
With the Boulder Badge you can continue to Route 3 and Mt. Moon. Starter gifts are later: Charmander on Route 24, Bulbasaur after Pikachu happiness 147, Squirtle after the Thunder Badge—see the all-starters tool if you are collecting the trio.