Why won't my Flash work outside in Gold and Silver?

You're missing the badge that switches it on. Flash only lights the field once you hold the Zephyr Badge from Falkner, even after you pick up the move itself as HM05 from the elder atop Sprout Tower. Several caves call for it: Dark Cave, Kanto's Rock Tunnel, Mt. Mortar, the Whirl Islands, and the inside of Mt. Silver are all pitch black enough to leave you fumbling without it.

Gold & Silver Rock Tunnel

Total blackness fills this tunnel boring through Kanto's eastern hills, no use to anyone without a light.

Rock Tunnel is in Kanto, with Route 9 to the west. In the story it comes after Lavender Town and continues south to Route 10.

ROCK TUNNEL MAP

Rock Tunnel stays pitch dark in these games, so Flash is the price of entry. Two floors of winding passages connect the two ends of Route 10, easy to get turned around in without a light.

Pokemon Encounters

Kangaskhan is the surprise of Rock Tunnel at 5 percent, a strong Normal-type that is tough to find anywhere else. Cubone and Machop work the dark alongside it, with Marowak deeper in.

Type

▾1F5

Walking5

#104Cubone

35% - Lv 10–13

#074Geodude

30% - Lv 10

#066Machop

20% - Lv 12

#041Zubat

10% - Lv 8

#067Machoke

5% - Lv 14

▾B1F6

Walking6

#104Cubone

30% - Lv 12

#074Geodude

30% - Lv 12

#095Onix

20% - Lv 16

#041Zubat

10% - Lv 10

#115Kangaskhan

5% - Lv 14

#105Marowak

5% - Lv 14

#104

Cubone

Ground

Evolves into Marowak at Lv 28

Encounter rate

35% Common

Level

10–13

EV yield

1 Defense

1 in 3wild encounters

will be Cubone — about 1m of walking through grass to catch one.

Catch odds

~3m-4m

to catch one

Poke Ball25%

Great Ball34%

Ultra Ball34%

Nuzlocke

community tier

Score40

PickRisky

SourceDerived

Shiny hunt

1/8,192

full odds

Base1/8,192

Expected117h 2m

Cubone only spawns wild here in this region. Catch one while you can.

Cubone page →

#074

Geodude

RockGround

Evolves into Graveler at Lv 25

Encounter rate

30% Common

Level

EV yield

1 Defense

1 in 3wild encounters

will be Geodude — about 1m of walking through grass to catch one.

Catch odds

~4m

to catch one

Poke Ball34%

Great Ball34%

Ultra Ball34%

Nuzlocke

community tier

Score40

PickRisky

SourceDerived

Shiny hunt

1/8,192

full odds

Base1/8,192

Expected136h 32m

Also found in 7 other locations

Dark CaveLv 2–23

60%Mt. MortarLv 13–31

30%Team Rocket HQLv 21–21

Geodude page →

#104

Cubone

Ground

Evolves into Marowak at Lv 28

Encounter rate

30% Common

Level

EV yield

1 Defense

1 in 3wild encounters

will be Cubone — about 1m of walking through grass to catch one.

Catch odds

~4m-5m

to catch one

Poke Ball25%

Great Ball34%

Ultra Ball34%

Nuzlocke

community tier

Score40

PickRisky

SourceDerived

Shiny hunt

1/8,192

full odds

Base1/8,192

Expected136h 32m

Cubone only spawns wild here in this region. Catch one while you can.

Cubone page →

#074

Geodude

RockGround

Evolves into Graveler at Lv 25

Encounter rate

30% Common

Level

EV yield

1 Defense

1 in 3wild encounters

will be Geodude — about 1m of walking through grass to catch one.

Geodude page →

#066

Machop

Fighting

Evolves into Machoke at Lv 28

Encounter rate

20% Uncommon

Level

EV yield

1 Attack

1 in 5wild encounters

will be Machop — about 2m of walking through grass to catch one.

Catch odds

~5m-6m

to catch one

Poke Ball24%

Great Ball34%

Ultra Ball34%

Nuzlocke

community tier

Score20

PickLottery

SourceEstimated

Shiny hunt

1/8,192

full odds

Base1/8,192

Expected204h 48m

Also found in 2 other locations

Mt. MortarLv 13–28

35%Goldenrod CityLv ?–?

Machop page →

#095

Onix

RockGround

Evolves into Steelix via trade

Encounter rate

20% Uncommon

Level

EV yield

1 Defense

1 in 5wild encounters

will be Onix — about 2m of walking through grass to catch one.

Catch odds

~13m-25m

to catch one

Poke Ball6%

Great Ball9%

Ultra Ball12%

Nuzlocke

community tier

Score20

PickLottery

SourceDerived

Shiny hunt

1/8,192

full odds

Base1/8,192

Expected204h 48m

Also found in 4 other locations

Mt. SilverLv 42–48

30%Victory RoadLv 34–36

15%Union CaveLv 6–23

10%Violet CityLv ?–?

Onix page →

#041

Zubat

PoisonFlying

Evolves into Golbat at Lv 22

Encounter rate

10% Rare

Level

EV yield

1 Speed

1 in 10wild encounters

will be Zubat — about 7m of walking through grass to catch one.

Catch odds

~9m

to catch one

Poke Ball34%

Great Ball34%

Ultra Ball34%

Nuzlocke

community tier

Score40

PickRisky

SourceDerived

Shiny hunt

1/8,192

full odds

Base1/8,192

Expected409h 36m

Also found in 15 other locations

Slowpoke WellLv 5–23

85%Mt. MortarLv 13–17

30%Tohjo FallsLv 22–22

30%Union CaveLv 5–22

30%Whirl IslandsLv 23–25

30%Ilex ForestLv 5–6

25%Ice PathLv 22–24

25%Burned TowerLv 14–15

10%Route 32Lv 4–8

Zubat page →

#041

Zubat

PoisonFlying

Evolves into Golbat at Lv 22

Encounter rate

10% Rare

Level

EV yield

1 Speed

1 in 10wild encounters

will be Zubat — about 7m of walking through grass to catch one.

Zubat page →

#067

Machoke

Fighting

Evolves into Machamp via trade

Encounter rate

5% V.Rare

Level

EV yield

2 Attack

+10

1 in 20wild encounters

will be Machoke — about 20m of walking through grass to catch one.

Catch odds

~25m-50m

to catch one

Poke Ball12%

Great Ball18%

Ultra Ball24%

Nuzlocke

community tier

Score40

PickRisky

SourceDerived

Shiny hunt

1/8,192

full odds

Base1/8,192

Expected819h 12m

Also found in 1 other location

Mt. MortarLv 32–32

30%

Machoke page →

#115

Kangaskhan

Normal

Encounter rate

5% V.Rare

Level

EV yield

2 HP

+10

1 in 20wild encounters

will be Kangaskhan — about 20m of walking through grass to catch one.

Catch odds

~50m-1h 40m

to catch one

Poke Ball6%

Great Ball9%

Ultra Ball12%

Nuzlocke

community tier

Score60

PickRisky

SourceDerived

Shiny hunt

1/8,192

full odds

Base1/8,192

Expected819h 12m

Kangaskhan only spawns wild here in this region. Catch one while you can.

Kangaskhan page →

#105

Marowak

Ground

Encounter rate

5% V.Rare

Level

EV yield

2 Defense

+10

1 in 20wild encounters

will be Marowak — about 20m of walking through grass to catch one.

Catch odds

~30m-1h

to catch one

Poke Ball10%

Great Ball15%

Ultra Ball20%

Nuzlocke

community tier

Score60

PickRisky

SourceEstimated

Shiny hunt

1/8,192

full odds

Base1/8,192

Expected819h 12m

Marowak only spawns wild here in this region. Catch one while you can.

Marowak page →

ITEMS

Bring Flash into Rock Tunnel and you can grab TM47 Steel Wing for your Flying types, plus an Iron and a PP Up worth pocketing. X items hide in the side passages.

TM1

TM47 Steel Wing

Vitamin2

Iron

B1F

PP Up

B1F

Item ball2

Elixir

Revive

B1F

Hidden3

X Accuracy

X Defense

Max Potion

B1F

TM47 Steel Wing

Found on 1F · center platform

Move

Steel WingSteelPhysical

Power

Accuracy

90%

Steel Wing deals damage and has a 10% chance of raising the user's Defense by one stage.

VITAMIN

Iron

Found on B1F · south

Effect

Raises DEFENSE of one Pokemon.

VITAMIN

PP Up

Found on B1F · west

Effect

Raises max PP of a selected move.

ITEM BALL

Elixir

Found on 1F · southwest

Effect

Restores PP of all moves by 10.

ITEM BALL

Revive

Found on B1F · north

Effect

Restores a fainted Pokemon to 1/2 HP.

HIDDEN

X Accuracy

Found on 1F · northeast (hidden)

Effect

Raises accuracy. (1 BTL)

HIDDEN

X Defense

Found on 1F · east of TM47 (hidden)

Effect

Raises DEFENSE. (1 BTL)

HIDDEN

Max Potion

Found on B1F · northwest of PP Up (hidden)

Effect

Fully restores Pokemon HP.

TM1

TM47 Steel Wing

Found on 1F · center platform

Move

Steel WingSteelPhysical

Power

Accuracy

90%

Steel Wing deals damage and has a 10% chance of raising the user's Defense by one stage.

Vitamin2

Iron

B1F

VITAMIN

Iron

Found on B1F · south

Effect

Raises DEFENSE of one Pokemon.

PP Up

B1F

VITAMIN

PP Up

Found on B1F · west

Effect

Raises max PP of a selected move.

Item ball2

Elixir

ITEM BALL

Elixir

Found on 1F · southwest

Effect

Restores PP of all moves by 10.

Revive

B1F

ITEM BALL

Revive

Found on B1F · north

Effect

Restores a fainted Pokemon to 1/2 HP.

Hidden3

X Accuracy

HIDDEN

X Accuracy

Found on 1F · northeast (hidden)

Effect

Raises accuracy. (1 BTL)

X Defense

HIDDEN

X Defense

Found on 1F · east of TM47 (hidden)

Effect

Raises DEFENSE. (1 BTL)

Max Potion

B1F

HIDDEN

Max Potion

Found on B1F · northwest of PP Up (hidden)

Effect

Fully restores Pokemon HP.

Rock Tunnel Guide

You're missing the badge that switches it on. Flash only lights the field once you hold the Zephyr Badge from Falkner, even after you pick up the move itself as HM05 from the elder atop Sprout Tower. Several caves call for it: Dark Cave, Kanto's Rock Tunnel, Mt. Mortar, the Whirl Islands, and the inside of Mt. Silver are all pitch black enough to leave you fumbling without it.