Part 3: 2 badges — beat Misty (Cascade Badge)
Thunder Badge territory opens.
2 badges — beat Misty (Cascade Badge) opens 24 areas. There are 99 trainers standing in them. The fights at this checkpoint are Lt. Surge, Rival Blue (Charmander) — rematch 3, Rival Blue (Squirtle) — rematch 3, and 8 more.
Where to go
Vermilion City
Wild: Goldeen 40% · Lv 14, Shellder 30% · Lv 13, Cheep 20% · Lv 15, Tentacool 11% · Lv 13
Route 5
Wild: Ekans 35.1% · Lv 13-15, Oddish 19.9% · Lv 13, Bellsprout 14.9% · Lv 15-16, Jigglypuff 11% · Lv 12-14 +2 more
Route 6
Wild: Magikarp 40% · Lv 12, Psyduck 35.1% · Lv 12-15, Orfry 30% · Lv 12, Slowpoke 29.7% · Lv 12-15 +12 more
Trainers: Bug Catcher #10 Lv 16, Bug Catcher #11 Lv 17, Jr. Trainer♂ #4 Lv 16, Jr. Trainer♂ #5 Lv 16, Jr. Trainer♀ #2 Lv 20, Jr. Trainer♀ #3 Lv 16
Route 9
Wild: Rattata 29.7% · Lv 15-16, Ekans 25% · Lv 13-14, Spearow 19.9% · Lv 16, Magnemite 9.8% · Lv 15 +3 more
Trainers: Bug Catcher #13 Lv 19, Bug Catcher #14 Lv 20, Jr. Trainer♂ #7 Lv 21, Jr. Trainer♂ #8 Lv 19, Jr. Trainer♀ #5 Lv 18, Jr. Trainer♀ #6 Lv 23 +2 more
Route 10
Wild: Poliwag 40% · Lv 17, Ribbito 30% · Lv 17, Krabby 20% · Lv 19, Magnemite 19.9% · Lv 16 +8 more
Trainers: Jr. Trainer♀ #7 Lv 20, Jr. Trainer♀ #8 Lv 21, Pokémaniac #1 Lv 30, Pokémaniac #2 Lv 21, Hiker #7 Lv 21, Hiker #8 Lv 19
Route 24
Wild: Magikarp 40% · Lv 12, Orfry 30% · Lv 13, Bellsprout 29.7% · Lv 13-14, Oddish 29.7% · Lv 13-14 +5 more
Trainers: Youngster #4 Lv 14, Bug Catcher #9 Lv 14, Lass #7 Lv 16, Lass #8 Lv 16, Jr. Trainer♂ #2 Lv 14, Jr. Trainer♂ #3 Lv 18 +1 more
Route 25
Wild: Magikarp 40% · Lv 11, Poliwag 30% · Lv 12, Spearow 25% · Lv 13-14, Venonat 20.3% · Lv 12-13 +6 more
Trainers: Youngster #5 Lv 15, Youngster #6 Lv 15, Youngster #7 Lv 14, Lass #9 Lv 15, Lass #10 Lv 13, Hiker #2 Lv 15 +2 more
Rock Tunnel 1F
Wild: Poliwag 40% · Lv 16, Zubat 39.8% · Lv 16-17, Ribbito 30% · Lv 16, Geodude 25% · Lv 16-17 +5 more
Trainers: Jr. Trainer♀ #17 Lv 22, Jr. Trainer♀ #18 Lv 20, Jr. Trainer♀ #19 Lv 19, Pokémaniac #7 Lv 23, Hiker #12 Lv 19, Hiker #13 Lv 20 +1 more
Power Plant
Wild: Voltorb 29.7% · Lv 32-33, Gaotora 25% · Lv 32-33, Magnetite 19.9% · Lv 32, Pikachu 9.8% · Lv 33 +3 more
Vermilion Dock
Wild: Magikarp 40% · Lv 15, Blottle 30% · Lv 13, Cheep 20% · Lv 15, Tentacool 11% · Lv 15
Pokemon Tower 2F
Wild: Gastly 39.8% · Lv 20-21, Vulpiii 25% · Lv 15-18, Vulpix 19.6% · Lv 20-24, Cubone 10.2% · Lv 20-22 +2 more
Pokemon Tower 5F
Wild: Gastly 39.8% · Lv 20-21, Vulpiii 25% · Lv 15-16, Vulpix 19.6% · Lv 23-24, Cubone 9.4% · Lv 20-22 +2 more
Trainers: Channeler #14 Lv 23, Channeler #16 Lv 22, Channeler #17 Lv 24, Channeler #18 Lv 22
Pokemon Tower 6F
Wild: Gastly 39.8% · Lv 21-22, Cubone 25% · Lv 22-24, Vulpix 19.6% · Lv 20-23, Haunter 9.4% · Lv 26-27 +2 more
Trainers: Channeler #19 Lv 22, Channeler #20 Lv 24, Channeler #21 Lv 30
Pokemon Tower 7F
Wild: Gastly 39.8% · Lv 21-22, Cubone 25.4% · Lv 21-24, Vulpix 19.6% · Lv 24-25, Haunter 9.8% · Lv 28 +2 more
Underwater Tunnel
Wild: Shellder 40% · Lv 30, Golbat 35.1% · Lv 33-34, Staryu 30% · Lv 29, Goldeen 29.7% · Lv 33-34 +10 more
Rock Tunnel B1F
Wild: Zubat 49.6% · Lv 16-18, Ribbito 25% · Lv 16-17, Machop 14.9% · Lv 15-17, Gavillain 5.5% · Lv 16-17 +1 more
Trainers: Jr. Trainer♀ #9 Lv 21, Jr. Trainer♀ #10 Lv 22, Pokémaniac #3 Lv 20, Pokémaniac #4 Lv 22, Pokémaniac #5 Lv 23, Hiker #9 Lv 21 +2 more
S.S. Anne 1F Rooms
Trainers: Youngster #8 Lv 21, Lass #11 Lv 18, Gentleman #1 Lv 18, Gentleman #2 Lv 19
S.S. Anne 2F Rooms
Trainers: Lass #12 Lv 18, Fisherman #1 Lv 17, Gentleman #3 Lv 23, Gentleman #5 Lv 17
S.S. Anne Bow
S.S. Anne B1F Rooms
Trainers: Sailor #3 Lv 21, Sailor #4 Lv 17, Sailor #5 Lv 18, Sailor #6 Lv 17, Sailor #7 Lv 20, Fisherman #2 Lv 17
Vermilion Gym
Trainers: Sailor #8 Lv 21, Rocker #1 Lv 20, ★ Lt. Surge Lv 14
SS Anne 2F
Trainers: ★ Rival Blue (Charmander) — rematch 3 Lv 21, ★ Rival Blue (Squirtle) — rematch 3 Lv 21, ★ Rival Blue (Bulbasaur) — rematch 3 Lv 21, ★ Rival Blue (Pikachu) — rematch 3 Lv 21, ★ Rival Blue (Eevee) — rematch 3 Lv 21
Pokémon Tower 2F
Trainers: ★ Rival Blue (Charmander) — rematch 4 Lv 25, ★ Rival Blue (Squirtle) — rematch 4 Lv 25, ★ Rival Blue (Bulbasaur) — rematch 4 Lv 25, ★ Rival Blue (Pikachu) — rematch 4 Lv 25, ★ Rival Blue (Eevee) — rematch 4 Lv 25
Pokemon Tower 3F
Trainers: Channeler #1 Lv 22, Channeler #2 Lv 24, Channeler #3 Lv 23, Channeler #4 Lv 24, Channeler #5 Lv 23, Channeler #6 Lv 24 +7 more
★ Lt. Surge — Vermilion Gym
| Pokémon | Moves | |
|---|---|---|
 | Voltorb Lv 11 | Thunder Wave |
 | Pikachu Lv 12 | Tail Whip Thundershock Quick Attack |
| Gaotora Lv 14 | Leer Roar Thunderbolt |
★ Rival Blue (Charmander) — rematch 3 — SS Anne 2F
| Pokémon | Moves | |
|---|---|---|
 | Pidgeotto Lv 19 | Sand-Attack Quick Attack |
 | Raticate Lv 18 | Quick Attack Hyper Fang |
 | Kadabra Lv 18 | Thunder Wave |
 | Wartortle Lv 21 | Bubble Water Gun Bite |
★ Rival Blue (Squirtle) — rematch 3 — SS Anne 2F
| Pokémon | Moves | |
|---|---|---|
| Pidgeotto Lv 19 | Sand-Attack Quick Attack |
| Raticate Lv 18 | Quick Attack Hyper Fang |
| Kadabra Lv 18 | Thunder Wave |
 | Ivysaur Lv 21 | Tackle Leech Seed Poisonpowder |
Also fought around here
This game's documentation doesn't say where 18 of its 471 fights happen, so those trainers are on no part of this walkthrough; they are all on the Trainers page. It also doesn't say when Faraway Island Inside, Digletts Cave open up, so they are in no part above; each has its own route page.