Part 2: Boulder Badge — beat Brock (Pewter City Gym)
Cut, Flash, Teleport
Boulder Badge — beat Brock (Pewter City Gym) opens 12 areas. There are 78 trainers standing in them. The fights at this checkpoint are Rival Blue (team 1), Rival Blue (team 2), Rival Blue (team 3), and 7 more.
Where to go
Route 3
Wild: Nosepass 35% · Lv 9-10, Geodude 25% · Lv 7, Hoothoot 25% · Lv 6-7, Spearow 25% · Lv 6-8 +22 more
Trainers: Bug Catcher Colton (Classic) Lv 10, Bug Catcher Colton (Remix) Lv 10, Bug Catcher Colton (Expert) Lv 10, Bug Catcher Greg (Classic) Lv 9, Bug Catcher Greg (Remix) Lv 9, Bug Catcher Greg (Expert) Lv 9 +18 more
Pick up: TM94 Rock Smash
Mt. Moon
Wild: Geodude 80% · Lv 9-10, Zubat 41% · Lv 8-11, Nosepass 25% · Lv 9-10, Cleffa 24% · Lv 8-11 +13 more
Trainers: Bug Catcher Kent (Classic) Lv 11, Bug Catcher Kent (Remix) Lv 11, Bug Catcher Kent (Expert) Lv 11, Bug Catcher Robby (Classic) Lv 12, Bug Catcher Robby (Remix) Lv 11, Bug Catcher Robby (Expert) Lv 11 +15 more
Pick up: TM09 Venoshock, TM37 Sandstorm, TM46 Thief, TM58 Sky Drop, TM96 Moonblast, TM106 Draining Kiss
Mt. Moon B1F
Wild: Geodude 80% · Lv 9-10, Zubat 41% · Lv 8-11, Nosepass 25% · Lv 9-10, Aron 21% · Lv 9-10 +14 more
Mt. Moon B2F
Wild: Geodude 95% · Lv 9-10, Zubat 49% · Lv 8-11, Cleffa 27% · Lv 8-11, Nosepass 25% · Lv 9-10 +13 more
Trainers: Super Nerd Miguel (Classic) Lv 16, Super Nerd Miguel (Remix) Lv 14, Super Nerd Miguel (Expert) Lv 16, Team Rocket Samantha (Classic) Lv 13, Team Rocket Samantha (Remix) Lv 13, Team Rocket Samantha (Expert) Lv 13 +9 more
Pick up: TM46 Thief
Mt. Moon (area 2)
Wild: Geodude 80% · Lv 9-10, Zubat 41% · Lv 8-11, Cleffa 29% · Lv 6-9, Nosepass 25% · Lv 9-10 +11 more
Pick up: TM106 Draining Kiss
Mt. Moon (area 4)
Wild: Geodude 95% · Lv 9-10, Zubat 41% · Lv 8-11, Nosepass 25% · Lv 9-10, Cleffa 23% · Lv 8-11 +13 more
Mt. Moon Summit
Wild: Swablu 40% · Lv 18-21, Clefairy 35% · Lv 18-21, Geodude 30% · Lv 18-21, Graveler 20% · Lv 23-26 +11 more
Pick up: TM58 Sky Drop, TM96 Moonblast
Route 4
Wild: Magikarp 80% · Lv 5, Tentacool 60% · Lv 5-40, Dhelmise 40% · Lv 5-15, Horsea 40% · Lv 5-15 +36 more
Trainers: Lass Crissy (Classic) Lv 31, Lass Crissy (Remix) Lv 46, Lass Crissy (Expert) Lv 31
Route 4 (area 3)
Wild: Unown 100% · Lv 1-2, Magikarp 80% · Lv 5, Tentacool 60% · Lv 5-40, Horsea 40% · Lv 5-15 +17 more
Cerulean City
Wild: Magikarp 80% · Lv 5, Tentacool 60% · Lv 5-40, Dhelmise 40% · Lv 5-15, Horsea 40% · Lv 5-15 +17 more
Trainers: Lass Jen Lv 20, ★ Rival Blue (team 1) Lv 19, ★ Rival Blue (team 2) Lv 19, ★ Rival Blue (team 3) Lv 19, ★ Rival Blue (team 4) Lv 19, ★ Rival Blue (team 5) Lv 19 +1 more
Pick up: TM11 Sunny Day, TM40 Aerial Ace, TM55 Water Pulse
Cerulean City Gym
Trainers: Lass Diana Lv 19, ★ Gym Leader Misty (Classic) Lv 22, ★ Gym Leader Misty (Remix) Lv 22, ★ Gym Leader Misty (Expert) Lv 22, Swimmer Luis (Classic) Lv 16, Swimmer Luis (Remix) Lv 16 +1 more
Cerulean Hotel
Trainers: ★ Type Expert Tim Lv 30
★ Rival Blue (team 1) — Cerulean City
| Pokémon | Moves | |
|---|---|---|
 | Nidorino Lv 18 · Tangled Feet Nidotto — a fusion: body Pidgeotto, head Nidorino. Poison/Flying, 61/64/55/52/52/68. Shown under its head, because there is no sprite for a fusion here. | |
 | Abra Lv 15 · Synchronize | |
 | Mankey Lv 16 · Run Away Mantata — a fusion: body Rattata, head Mankey. Fighting/Normal, 36/63/34/31/41/71. Shown under its head, because there is no sprite for a fusion here. | |
| Rival's starter Lv 19 · — The game swaps this in for a fusion of the two starters you didn't take, so what you face depends on the one you picked. | Scary Face Water Gun Ember Slash |
★ Rival Blue (team 2) — Cerulean City
| Pokémon | Moves | |
|---|---|---|
 | Cottonee Lv 17 · Intimidate Cottonx — a fusion: body Shinx, head Cottonee. Grass/Electric, 41/52/42/37/44/52. Shown under its head, because there is no sprite for a fusion here. | Spark Leech Seed Mega Drain Stun Spore |
 | Goomy Lv 15 · Sap Sipper | Bubble Absorb Protect Bide |
 | Eevee Lv 17 · Run Away · Focus Sash | Quick Attack Swift Bite Wish |
 | Dratini Lv 19 · Marvel Scale · Oran Berry Dratini — a fusion: body Dratini, head Dratini. Dragon/Dragon, 40/63/45/49/49/49. Shown under its head, because there is no sprite for a fusion here. | Thunder Wave Dragon Rage Water Pulse Iron Tail |
★ Rival Blue (team 3) — Cerulean City
| Pokémon | Moves | |
|---|---|---|
 | Gyarados Lv 18 · Guts · Flame Orb Gyaraicate — a fusion: body Raticate, head Gyarados. Water/Normal, 81/95/66/56/89/91. Shown under its head, because there is no sprite for a fusion here. | Aqua Tail Thrash Rock Smash Ice Fang |
 | Fearow Lv 18 · Sniper · Muscle Band Feareary — a fusion: body Buneary, head Fearow. Flying/Normal, 61/74/50/54/58/89. Shown under its head, because there is no sprite for a fusion here. | Frustration Drill Run Work Up Aerial Ace |
 | Nidoking Lv 18 · Sheer Force · Sitrus Berry | Water Pulse Megahorn Rock Tomb Rock Smash |
| Rival's starter Lv 19 · — · Expert Belt The game swaps this in for a fusion of the two starters you didn't take, so what you face depends on the one you picked. |
Also fought around here
This game's documentation doesn't say where 8 of its 1653 fights happen, so those trainers are on no part of this walkthrough; they are all on the Trainers page.