On this page
  1. Where a step can meet one
  2. What’s in the grass
  3. Repel
  4. Fishing
  5. Related
  6. References
  7. Sources

A step in grass starts a wild battle 251 times in 256 on Route 1, about once every 10.22 steps, and only 83 times in 256 in Viridian Forest, once every 322,1,2. Each battle then draws one of ten slots, some far rarer than others, and each slot holds one species at one level4,5. A Pikachu fills two of Viridian Forest’s slots, 5.53% of its battles, so finding one takes about 6203 steps of grass on average, a turn in place counting as a step3.

A Repel doesn’t bring it sooner. It turns away only wild Pokémon below the level of the first Pokémon in the party, after the step has already picked them, so it spares the battles in between but not the steps6,7. A Repel can even turn away the Pokémon wanted: ahead of anything stronger than the weaker of Viridian Forest’s two Pikachu, it stretches the walk to about 28003 steps3.

In Red, with no Repel and a level 5 Pokémon first in the party, each step or turn in place in Viridian Forest's grass starts a battle 3.1% of the time. Of the wild Pokémon that turn up there, 5.5% are a Pikachu that gets to battle, so a step or turn meets one 0.2% of the time.

Interactive: formula-lab (needs JavaScript)

The ten slots, by place and Pokémon

#Where a step can meet one

In caves, Pokémon Tower, the Power Plant, and Pokémon Mansion every step off the water can start a battle; on routes, in Viridian Forest, and in the Safari Zone only a step in grass or on water can8. A turn counts as a step: pressing a new direction while standing turns the player in place first, and the turn rolls on the tile underfoot8. Surfing on open water meets only Tentacool, and only on Routes 19, 20, and 21, the three places with a water list; the water in Seafoam Islands and Cerulean Cave meets nothing9. A shore whose water shows only in the bottom-right corner of the player’s square, as on Cinnabar Island’s east coast, rolls the water rate but draws from the grass list10.

Some steps can’t start a battle anywhere: the first two after a battle, a ledge jump, a step out of a door, and a step onto a door or a warp11,12. A turn in place doesn’t count toward those two, and can’t start a battle before they’re taken11. Those two steps after each battle are part of the averages above3.

#What’s in the grass

Every place has its own ten slots, and the slots’ weights are the same everywhere, 51 · 51 · 39 · 25 · 25 · 25 · 13 · 13 · 11 · 3 (of 256)4,4. A species in the last slot alone comes up about once in 85.37 battles, as Mt. Moon’s Clefairy does7. Red and Blue fill many slots differently, Route 4’s Ekans in Red with Sandshrew in Blue among them, and almost always the level stays the same5.

MapTerrainRateSlotChanceRed levelRedBlue levelBlueRed No.Blue No.
Route 1grass250513PIDGEY3PIDGEY1616
Route 1grass251513RATTATA3RATTATA1919
Route 1grass252393RATTATA3RATTATA1919
Route 1grass253252RATTATA2RATTATA1919
Route 1grass254252PIDGEY2PIDGEY1616
Route 1grass255253PIDGEY3PIDGEY1616
Route 1grass256133PIDGEY3PIDGEY1616
Route 1grass257134RATTATA4RATTATA1919
Route 1grass258114PIDGEY4PIDGEY1616
Route 1grass25935PIDGEY5PIDGEY1616
Route 2grass250513RATTATA3RATTATA1919
Route 2grass251513PIDGEY3PIDGEY1616
Route 2grass252394PIDGEY4PIDGEY1616
Route 2grass253254RATTATA4RATTATA1919
Route 2grass254255PIDGEY5PIDGEY1616
Route 2grass255253WEEDLE3CATERPIE1310
Route 2grass256132RATTATA2RATTATA1919
Route 2grass257135RATTATA5RATTATA1919
Route 2grass258114WEEDLE4CATERPIE1310
Route 2grass25935WEEDLE5CATERPIE1310
Route 3grass200516PIDGEY6PIDGEY1616
Route 3grass201515SPEAROW5SPEAROW2121
Route 3grass202397PIDGEY7PIDGEY1616
Route 3grass203256SPEAROW6SPEAROW2121
Route 3grass204257SPEAROW7SPEAROW2121
Route 3grass205258PIDGEY8PIDGEY1616
Route 3grass206138SPEAROW8SPEAROW2121
Route 3grass207133JIGGLYPUFF3JIGGLYPUFF3939
Route 3grass208115JIGGLYPUFF5JIGGLYPUFF3939
Route 3grass20937JIGGLYPUFF7JIGGLYPUFF3939
Route 4grass2005110RATTATA10RATTATA1919
Route 4grass2015110SPEAROW10SPEAROW2121
Route 4grass202398RATTATA8RATTATA1919
Route 4grass203256EKANS6SANDSHREW2327
Route 4grass204258SPEAROW8SPEAROW2121
Route 4grass2052510EKANS10SANDSHREW2327
Route 4grass2061312RATTATA12RATTATA1919
Route 4grass2071312SPEAROW12SPEAROW2121
Route 4grass208118EKANS8SANDSHREW2327
Route 4grass209312EKANS12SANDSHREW2327
Route 5grass1505113ODDISH13BELLSPROUT4369
Route 5grass1515113PIDGEY13PIDGEY1616
Route 5grass1523915PIDGEY15PIDGEY1616
Route 5grass1532510MANKEY10MEOWTH5652
Route 5grass1542512MANKEY12MEOWTH5652
Route 5grass1552515ODDISH15BELLSPROUT4369
Route 5grass1561316ODDISH16BELLSPROUT4369
Route 5grass1571316PIDGEY16PIDGEY1616
Route 5grass1581114MANKEY14MEOWTH5652
Route 5grass159316MANKEY16MEOWTH5652
Route 6grass1505113ODDISH13BELLSPROUT4369
Route 6grass1515113PIDGEY13PIDGEY1616
Route 6grass1523915PIDGEY15PIDGEY1616
Route 6grass1532510MANKEY10MEOWTH5652
Route 6grass1542512MANKEY12MEOWTH5652
Route 6grass1552515ODDISH15BELLSPROUT4369
Route 6grass1561316ODDISH16BELLSPROUT4369
Route 6grass1571316PIDGEY16PIDGEY1616
Route 6grass1581114MANKEY14MEOWTH5652
Route 6grass159316MANKEY16MEOWTH5652
Route 7grass1505119PIDGEY19PIDGEY1616
Route 7grass1515119ODDISH19BELLSPROUT4369
Route 7grass1523917MANKEY17MEOWTH5652
Route 7grass1532522ODDISH22BELLSPROUT4369
Route 7grass1542522PIDGEY22PIDGEY1616
Route 7grass1552518MANKEY18MEOWTH5652
Route 7grass1561318GROWLITHE18VULPIX5837
Route 7grass1571320GROWLITHE20VULPIX5837
Route 7grass1581119MANKEY19MEOWTH5652
Route 7grass159320MANKEY20MEOWTH5652
Route 8grass1505118PIDGEY18PIDGEY1616
Route 8grass1515118MANKEY18MEOWTH5652
Route 8grass1523917EKANS17SANDSHREW2327
Route 8grass1532516GROWLITHE16VULPIX5837
Route 8grass1542520PIDGEY20PIDGEY1616
Route 8grass1552520MANKEY20MEOWTH5652
Route 8grass1561319EKANS19SANDSHREW2327
Route 8grass1571317GROWLITHE17VULPIX5837
Route 8grass1581115GROWLITHE15VULPIX5837
Route 8grass159318GROWLITHE18VULPIX5837
Route 9grass1505116RATTATA16RATTATA1919
Route 9grass1515116SPEAROW16SPEAROW2121
Route 9grass1523914RATTATA14RATTATA1919
Route 9grass1532511EKANS11SANDSHREW2327
Route 9grass1542513SPEAROW13SPEAROW2121
Route 9grass1552515EKANS15SANDSHREW2327
Route 9grass1561317RATTATA17RATTATA1919
Route 9grass1571317SPEAROW17SPEAROW2121
Route 9grass1581113EKANS13SANDSHREW2327
Route 9grass159317EKANS17SANDSHREW2327
Route 10grass1505116VOLTORB16VOLTORB100100
Route 10grass1515116SPEAROW16SPEAROW2121
Route 10grass1523914VOLTORB14VOLTORB100100
Route 10grass1532511EKANS11SANDSHREW2327
Route 10grass1542513SPEAROW13SPEAROW2121
Route 10grass1552515EKANS15SANDSHREW2327
Route 10grass1561317VOLTORB17VOLTORB100100
Route 10grass1571317SPEAROW17SPEAROW2121
Route 10grass1581113EKANS13SANDSHREW2327
Route 10grass159317EKANS17SANDSHREW2327
Route 11grass1505114EKANS14SANDSHREW2327
Route 11grass1515115SPEAROW15SPEAROW2121
Route 11grass1523912EKANS12SANDSHREW2327
Route 11grass153259DROWZEE9DROWZEE9696
Route 11grass1542513SPEAROW13SPEAROW2121
Route 11grass1552513DROWZEE13DROWZEE9696
Route 11grass1561315EKANS15SANDSHREW2327
Route 11grass1571317SPEAROW17SPEAROW2121
Route 11grass1581111DROWZEE11DROWZEE9696
Route 11grass159315DROWZEE15DROWZEE9696
Route 12grass1505124ODDISH24BELLSPROUT4369
Route 12grass1515125PIDGEY25PIDGEY1616
Route 12grass1523923PIDGEY23PIDGEY1616
Route 12grass1532524VENONAT24VENONAT4848
Route 12grass1542522ODDISH22BELLSPROUT4369
Route 12grass1552526VENONAT26VENONAT4848
Route 12grass1561326ODDISH26BELLSPROUT4369
Route 12grass1571327PIDGEY27PIDGEY1616
Route 12grass1581128GLOOM28WEEPINBELL4470
Route 12grass159330GLOOM30WEEPINBELL4470
Route 13grass2005124ODDISH24BELLSPROUT4369
Route 13grass2015125PIDGEY25PIDGEY1616
Route 13grass2023927PIDGEY27PIDGEY1616
Route 13grass2032524VENONAT24VENONAT4848
Route 13grass2042522ODDISH22BELLSPROUT4369
Route 13grass2052526VENONAT26VENONAT4848
Route 13grass2061326ODDISH26BELLSPROUT4369
Route 13grass2071325DITTO25DITTO132132
Route 13grass2081128GLOOM28WEEPINBELL4470
Route 13grass209330GLOOM30WEEPINBELL4470
Route 14grass1505124ODDISH24BELLSPROUT4369
Route 14grass1515126PIDGEY26PIDGEY1616
Route 14grass1523923DITTO23DITTO132132
Route 14grass1532524VENONAT24VENONAT4848
Route 14grass1542522ODDISH22BELLSPROUT4369
Route 14grass1552526VENONAT26VENONAT4848
Route 14grass1561326ODDISH26BELLSPROUT4369
Route 14grass1571330GLOOM30WEEPINBELL4470
Route 14grass1581128PIDGEOTTO28PIDGEOTTO1717
Route 14grass159330PIDGEOTTO30PIDGEOTTO1717
Route 15grass1505124ODDISH24BELLSPROUT4369
Route 15grass1515126DITTO26DITTO132132
Route 15grass1523923PIDGEY23PIDGEY1616
Route 15grass1532526VENONAT26VENONAT4848
Route 15grass1542522ODDISH22BELLSPROUT4369
Route 15grass1552528VENONAT28VENONAT4848
Route 15grass1561326ODDISH26BELLSPROUT4369
Route 15grass1571330GLOOM30WEEPINBELL4470
Route 15grass1581128PIDGEOTTO28PIDGEOTTO1717
Route 15grass159330PIDGEOTTO30PIDGEOTTO1717
Route 16grass2505120SPEAROW20SPEAROW2121
Route 16grass2515122SPEAROW22SPEAROW2121
Route 16grass2523918RATTATA18RATTATA1919
Route 16grass2532520DODUO20DODUO8484
Route 16grass2542520RATTATA20RATTATA1919
Route 16grass2552518DODUO18DODUO8484
Route 16grass2561322DODUO22DODUO8484
Route 16grass2571322RATTATA22RATTATA1919
Route 16grass2581123RATICATE23RATICATE2020
Route 16grass259325RATICATE25RATICATE2020
Route 17grass2505120SPEAROW20SPEAROW2121
Route 17grass2515122SPEAROW22SPEAROW2121
Route 17grass2523925RATICATE25RATICATE2020
Route 17grass2532524DODUO24DODUO8484
Route 17grass2542527RATICATE27RATICATE2020
Route 17grass2552526DODUO26DODUO8484
Route 17grass2561328DODUO28DODUO8484
Route 17grass2571329RATICATE29RATICATE2020
Route 17grass2581125FEAROW25FEAROW2222
Route 17grass259327FEAROW27FEAROW2222
Route 18grass2505120SPEAROW20SPEAROW2121
Route 18grass2515122SPEAROW22SPEAROW2121
Route 18grass2523925RATICATE25RATICATE2020
Route 18grass2532524DODUO24DODUO8484
Route 18grass2542525FEAROW25FEAROW2222
Route 18grass2552526DODUO26DODUO8484
Route 18grass2561328DODUO28DODUO8484
Route 18grass2571329RATICATE29RATICATE2020
Route 18grass2581127FEAROW27FEAROW2222
Route 18grass259329FEAROW29FEAROW2222
Routes 19 and 20water50515TENTACOOL5TENTACOOL7272
Routes 19 and 20water515110TENTACOOL10TENTACOOL7272
Routes 19 and 20water523915TENTACOOL15TENTACOOL7272
Routes 19 and 20water53255TENTACOOL5TENTACOOL7272
Routes 19 and 20water542510TENTACOOL10TENTACOOL7272
Routes 19 and 20water552515TENTACOOL15TENTACOOL7272
Routes 19 and 20water561320TENTACOOL20TENTACOOL7272
Routes 19 and 20water571330TENTACOOL30TENTACOOL7272
Routes 19 and 20water581135TENTACOOL35TENTACOOL7272
Routes 19 and 20water59340TENTACOOL40TENTACOOL7272
Route 21grass2505121RATTATA21RATTATA1919
Route 21grass2515123PIDGEY23PIDGEY1616
Route 21grass2523930RATICATE30RATICATE2020
Route 21grass2532523RATTATA23RATTATA1919
Route 21grass2542521PIDGEY21PIDGEY1616
Route 21grass2552530PIDGEOTTO30PIDGEOTTO1717
Route 21grass2561332PIDGEOTTO32PIDGEOTTO1717
Route 21grass2571328TANGELA28TANGELA114114
Route 21grass2581130TANGELA30TANGELA114114
Route 21grass259332TANGELA32TANGELA114114
Route 21water50515TENTACOOL5TENTACOOL7272
Route 21water515110TENTACOOL10TENTACOOL7272
Route 21water523915TENTACOOL15TENTACOOL7272
Route 21water53255TENTACOOL5TENTACOOL7272
Route 21water542510TENTACOOL10TENTACOOL7272
Route 21water552515TENTACOOL15TENTACOOL7272
Route 21water561320TENTACOOL20TENTACOOL7272
Route 21water571330TENTACOOL30TENTACOOL7272
Route 21water581135TENTACOOL35TENTACOOL7272
Route 21water59340TENTACOOL40TENTACOOL7272
Route 22grass250513RATTATA3RATTATA1919
Route 22grass251513NIDORAN♂3NIDORAN♀3229
Route 22grass252394RATTATA4RATTATA1919
Route 22grass253254NIDORAN♂4NIDORAN♀3229
Route 22grass254252RATTATA2RATTATA1919
Route 22grass255252NIDORAN♂2NIDORAN♀3229
Route 22grass256133SPEAROW3SPEAROW2121
Route 22grass257135SPEAROW5SPEAROW2121
Route 22grass258113NIDORAN♀3NIDORAN♂2932
Route 22grass25934NIDORAN♀4NIDORAN♂2932
Route 23grass1005126EKANS26SANDSHREW2327
Route 23grass1015133DITTO33DITTO132132
Route 23grass1023926SPEAROW26SPEAROW2121
Route 23grass1032538FEAROW38FEAROW2222
Route 23grass1042538DITTO38DITTO132132
Route 23grass1052538FEAROW38FEAROW2222
Route 23grass1061341ARBOK41SANDSLASH2428
Route 23grass1071343DITTO43DITTO132132
Route 23grass1081141FEAROW41FEAROW2222
Route 23grass109343FEAROW43FEAROW2222
Route 24grass250517WEEDLE7CATERPIE1310
Route 24grass251518KAKUNA8METAPOD1411
Route 24grass2523912PIDGEY12PIDGEY1616
Route 24grass2532512ODDISH12BELLSPROUT4369
Route 24grass2542513ODDISH13BELLSPROUT4369
Route 24grass2552510ABRA10ABRA6363
Route 24grass2561314ODDISH14BELLSPROUT4369
Route 24grass2571313PIDGEY13PIDGEY1616
Route 24grass258118ABRA8ABRA6363
Route 24grass259312ABRA12ABRA6363
Route 25grass150518WEEDLE8CATERPIE1310
Route 25grass151519KAKUNA9METAPOD1411
Route 25grass1523913PIDGEY13PIDGEY1616
Route 25grass1532512ODDISH12BELLSPROUT4369
Route 25grass1542513ODDISH13BELLSPROUT4369
Route 25grass1552512ABRA12ABRA6363
Route 25grass1561314ODDISH14BELLSPROUT4369
Route 25grass1571310ABRA10ABRA6363
Route 25grass158117METAPOD7KAKUNA1114
Route 25grass15938CATERPIE8WEEDLE1013
Viridian Forestgrass80514WEEDLE4CATERPIE1310
Viridian Forestgrass81515KAKUNA5METAPOD1411
Viridian Forestgrass82393WEEDLE3CATERPIE1310
Viridian Forestgrass83255WEEDLE5CATERPIE1310
Viridian Forestgrass84254KAKUNA4METAPOD1411
Viridian Forestgrass85256KAKUNA6METAPOD1411
Viridian Forestgrass86134METAPOD4KAKUNA1114
Viridian Forestgrass87133CATERPIE3WEEDLE1013
Viridian Forestgrass88113PIKACHU3PIKACHU2525
Viridian Forestgrass8935PIKACHU5PIKACHU2525
Mt. Moon 1Fgrass100518ZUBAT8ZUBAT4141
Mt. Moon 1Fgrass101517ZUBAT7ZUBAT4141
Mt. Moon 1Fgrass102399ZUBAT9ZUBAT4141
Mt. Moon 1Fgrass103258GEODUDE8GEODUDE7474
Mt. Moon 1Fgrass104256ZUBAT6ZUBAT4141
Mt. Moon 1Fgrass1052510ZUBAT10ZUBAT4141
Mt. Moon 1Fgrass1061310GEODUDE10GEODUDE7474
Mt. Moon 1Fgrass107138PARAS8PARAS4646
Mt. Moon 1Fgrass1081111ZUBAT11ZUBAT4141
Mt. Moon 1Fgrass10938CLEFAIRY8CLEFAIRY3535
Mt. Moon B1Fgrass100518ZUBAT8ZUBAT4141
Mt. Moon B1Fgrass101517ZUBAT7ZUBAT4141
Mt. Moon B1Fgrass102397GEODUDE7GEODUDE7474
Mt. Moon B1Fgrass103258GEODUDE8GEODUDE7474
Mt. Moon B1Fgrass104259ZUBAT9ZUBAT4141
Mt. Moon B1Fgrass1052510PARAS10PARAS4646
Mt. Moon B1Fgrass1061310ZUBAT10ZUBAT4141
Mt. Moon B1Fgrass1071311ZUBAT11ZUBAT4141
Mt. Moon B1Fgrass108119CLEFAIRY9CLEFAIRY3535
Mt. Moon B1Fgrass10939GEODUDE9GEODUDE7474
Mt. Moon B2Fgrass100519ZUBAT9ZUBAT4141
Mt. Moon B2Fgrass101519GEODUDE9GEODUDE7474
Mt. Moon B2Fgrass1023910ZUBAT10ZUBAT4141
Mt. Moon B2Fgrass1032510GEODUDE10GEODUDE7474
Mt. Moon B2Fgrass1042511ZUBAT11ZUBAT4141
Mt. Moon B2Fgrass1052510PARAS10PARAS4646
Mt. Moon B2Fgrass1061312PARAS12PARAS4646
Mt. Moon B2Fgrass1071310CLEFAIRY10CLEFAIRY3535
Mt. Moon B2Fgrass1081112ZUBAT12ZUBAT4141
Mt. Moon B2Fgrass109312CLEFAIRY12CLEFAIRY3535
Rock Tunnel 1Fgrass1505116ZUBAT16ZUBAT4141
Rock Tunnel 1Fgrass1515117ZUBAT17ZUBAT4141
Rock Tunnel 1Fgrass1523917GEODUDE17GEODUDE7474
Rock Tunnel 1Fgrass1532515MACHOP15MACHOP6666
Rock Tunnel 1Fgrass1542516GEODUDE16GEODUDE7474
Rock Tunnel 1Fgrass1552518ZUBAT18ZUBAT4141
Rock Tunnel 1Fgrass1561315ZUBAT15ZUBAT4141
Rock Tunnel 1Fgrass1571317MACHOP17MACHOP6666
Rock Tunnel 1Fgrass1581113ONIX13ONIX9595
Rock Tunnel 1Fgrass159315ONIX15ONIX9595
the Power Plantgrass1005121VOLTORB21VOLTORB100100
the Power Plantgrass1015121MAGNEMITE21MAGNEMITE8181
the Power Plantgrass1023920PIKACHU20PIKACHU2525
the Power Plantgrass1032524PIKACHU24PIKACHU2525
the Power Plantgrass1042523MAGNEMITE23MAGNEMITE8181
the Power Plantgrass1052523VOLTORB23VOLTORB100100
the Power Plantgrass1061332MAGNETON32MAGNETON8282
the Power Plantgrass1071335MAGNETON35MAGNETON8282
the Power Plantgrass1081133ELECTABUZZ33RAICHU12526
the Power Plantgrass109336ELECTABUZZ36RAICHU12526
Victory Road 1Fgrass1505124MACHOP24MACHOP6666
Victory Road 1Fgrass1515126GEODUDE26GEODUDE7474
Victory Road 1Fgrass1523922ZUBAT22ZUBAT4141
Victory Road 1Fgrass1532536ONIX36ONIX9595
Victory Road 1Fgrass1542539ONIX39ONIX9595
Victory Road 1Fgrass1552542ONIX42ONIX9595
Victory Road 1Fgrass1561341GRAVELER41GRAVELER7575
Victory Road 1Fgrass1571341GOLBAT41GOLBAT4242
Victory Road 1Fgrass1581142MACHOKE42MACHOKE6767
Victory Road 1Fgrass159343MAROWAK43MAROWAK105105
Pokémon Tower 3Fgrass1005120GASTLY20GASTLY9292
Pokémon Tower 3Fgrass1015121GASTLY21GASTLY9292
Pokémon Tower 3Fgrass1023922GASTLY22GASTLY9292
Pokémon Tower 3Fgrass1032523GASTLY23GASTLY9292
Pokémon Tower 3Fgrass1042519GASTLY19GASTLY9292
Pokémon Tower 3Fgrass1052518GASTLY18GASTLY9292
Pokémon Tower 3Fgrass1061324GASTLY24GASTLY9292
Pokémon Tower 3Fgrass1071320CUBONE20CUBONE104104
Pokémon Tower 3Fgrass1081122CUBONE22CUBONE104104
Pokémon Tower 3Fgrass109325HAUNTER25HAUNTER9393
Pokémon Tower 4Fgrass1005120GASTLY20GASTLY9292
Pokémon Tower 4Fgrass1015121GASTLY21GASTLY9292
Pokémon Tower 4Fgrass1023922GASTLY22GASTLY9292
Pokémon Tower 4Fgrass1032523GASTLY23GASTLY9292
Pokémon Tower 4Fgrass1042519GASTLY19GASTLY9292
Pokémon Tower 4Fgrass1052518GASTLY18GASTLY9292
Pokémon Tower 4Fgrass1061325HAUNTER25HAUNTER9393
Pokémon Tower 4Fgrass1071320CUBONE20CUBONE104104
Pokémon Tower 4Fgrass1081122CUBONE22CUBONE104104
Pokémon Tower 4Fgrass109324GASTLY24GASTLY9292
Pokémon Tower 5Fgrass1005120GASTLY20GASTLY9292
Pokémon Tower 5Fgrass1015121GASTLY21GASTLY9292
Pokémon Tower 5Fgrass1023922GASTLY22GASTLY9292
Pokémon Tower 5Fgrass1032523GASTLY23GASTLY9292
Pokémon Tower 5Fgrass1042519GASTLY19GASTLY9292
Pokémon Tower 5Fgrass1052518GASTLY18GASTLY9292
Pokémon Tower 5Fgrass1061325HAUNTER25HAUNTER9393
Pokémon Tower 5Fgrass1071320CUBONE20CUBONE104104
Pokémon Tower 5Fgrass1081122CUBONE22CUBONE104104
Pokémon Tower 5Fgrass109324GASTLY24GASTLY9292
Pokémon Tower 6Fgrass1505121GASTLY21GASTLY9292
Pokémon Tower 6Fgrass1515122GASTLY22GASTLY9292
Pokémon Tower 6Fgrass1523923GASTLY23GASTLY9292
Pokémon Tower 6Fgrass1532524GASTLY24GASTLY9292
Pokémon Tower 6Fgrass1542520GASTLY20GASTLY9292
Pokémon Tower 6Fgrass1552519GASTLY19GASTLY9292
Pokémon Tower 6Fgrass1561326HAUNTER26HAUNTER9393
Pokémon Tower 6Fgrass1571322CUBONE22CUBONE104104
Pokémon Tower 6Fgrass1581124CUBONE24CUBONE104104
Pokémon Tower 6Fgrass159328HAUNTER28HAUNTER9393
Pokémon Tower 7Fgrass1505121GASTLY21GASTLY9292
Pokémon Tower 7Fgrass1515122GASTLY22GASTLY9292
Pokémon Tower 7Fgrass1523923GASTLY23GASTLY9292
Pokémon Tower 7Fgrass1532524GASTLY24GASTLY9292
Pokémon Tower 7Fgrass1542520GASTLY20GASTLY9292
Pokémon Tower 7Fgrass1552528HAUNTER28HAUNTER9393
Pokémon Tower 7Fgrass1561322CUBONE22CUBONE104104
Pokémon Tower 7Fgrass1571324CUBONE24CUBONE104104
Pokémon Tower 7Fgrass1581128HAUNTER28HAUNTER9393
Pokémon Tower 7Fgrass159330HAUNTER30HAUNTER9393
Seafoam Islands B1Fgrass1005130STARYU30SHELLDER12090
Seafoam Islands B1Fgrass1015130HORSEA30KRABBY11698
Seafoam Islands B1Fgrass1023932SHELLDER32STARYU90120
Seafoam Islands B1Fgrass1032532HORSEA32KRABBY11698
Seafoam Islands B1Fgrass1042528SLOWPOKE28PSYDUCK7954
Seafoam Islands B1Fgrass1052530SEEL30SEEL8686
Seafoam Islands B1Fgrass1061330SLOWPOKE30PSYDUCK7954
Seafoam Islands B1Fgrass1071328SEEL28SEEL8686
Seafoam Islands B1Fgrass1081138DEWGONG38DEWGONG8787
Seafoam Islands B1Fgrass109337SEADRA37KINGLER11799
Seafoam Islands B2Fgrass1005130SEEL30SEEL8686
Seafoam Islands B2Fgrass1015130SLOWPOKE30PSYDUCK7954
Seafoam Islands B2Fgrass1023932SEEL32SEEL8686
Seafoam Islands B2Fgrass1032532SLOWPOKE32PSYDUCK7954
Seafoam Islands B2Fgrass1042528HORSEA28KRABBY11698
Seafoam Islands B2Fgrass1052530STARYU30SHELLDER12090
Seafoam Islands B2Fgrass1061330HORSEA30KRABBY11698
Seafoam Islands B2Fgrass1071328SHELLDER28STARYU90120
Seafoam Islands B2Fgrass1081130GOLBAT30GOLBAT4242
Seafoam Islands B2Fgrass109337SLOWBRO37GOLDUCK8055
Seafoam Islands B3Fgrass1005131SLOWPOKE31PSYDUCK7954
Seafoam Islands B3Fgrass1015131SEEL31SEEL8686
Seafoam Islands B3Fgrass1023933SLOWPOKE33PSYDUCK7954
Seafoam Islands B3Fgrass1032533SEEL33SEEL8686
Seafoam Islands B3Fgrass1042529HORSEA29KRABBY11698
Seafoam Islands B3Fgrass1052531SHELLDER31STARYU90120
Seafoam Islands B3Fgrass1061331HORSEA31KRABBY11698
Seafoam Islands B3Fgrass1071329SHELLDER29STARYU90120
Seafoam Islands B3Fgrass1081139SEADRA39KINGLER11799
Seafoam Islands B3Fgrass109337DEWGONG37DEWGONG8787
Seafoam Islands B4Fgrass1005131HORSEA31KRABBY11698
Seafoam Islands B4Fgrass1015131SHELLDER31STARYU90120
Seafoam Islands B4Fgrass1023933HORSEA33KRABBY11698
Seafoam Islands B4Fgrass1032533SHELLDER33STARYU90120
Seafoam Islands B4Fgrass1042529SLOWPOKE29PSYDUCK7954
Seafoam Islands B4Fgrass1052531SEEL31SEEL8686
Seafoam Islands B4Fgrass1061331SLOWPOKE31PSYDUCK7954
Seafoam Islands B4Fgrass1071329SEEL29SEEL8686
Seafoam Islands B4Fgrass1081139SLOWBRO39GOLDUCK8055
Seafoam Islands B4Fgrass109332GOLBAT32GOLBAT4242
Pokémon Mansion 1Fgrass1005132KOFFING32GRIMER10988
Pokémon Mansion 1Fgrass1015130KOFFING30GRIMER10988
Pokémon Mansion 1Fgrass1023934PONYTA34PONYTA7777
Pokémon Mansion 1Fgrass1032530PONYTA30PONYTA7777
Pokémon Mansion 1Fgrass1042534GROWLITHE34VULPIX5837
Pokémon Mansion 1Fgrass1052532PONYTA32PONYTA7777
Pokémon Mansion 1Fgrass1061330GRIMER30KOFFING88109
Pokémon Mansion 1Fgrass1071328PONYTA28PONYTA7777
Pokémon Mansion 1Fgrass1081137WEEZING37MUK11089
Pokémon Mansion 1Fgrass109339MUK39WEEZING89110
Seafoam Islands 1Fgrass1505130SEEL30SEEL8686
Seafoam Islands 1Fgrass1515130SLOWPOKE30PSYDUCK7954
Seafoam Islands 1Fgrass1523930SHELLDER30STARYU90120
Seafoam Islands 1Fgrass1532530HORSEA30KRABBY11698
Seafoam Islands 1Fgrass1542528HORSEA28KRABBY11698
Seafoam Islands 1Fgrass1552521ZUBAT21ZUBAT4141
Seafoam Islands 1Fgrass1561329GOLBAT29GOLBAT4242
Seafoam Islands 1Fgrass1571328PSYDUCK28SLOWPOKE5479
Seafoam Islands 1Fgrass1581128SHELLDER28STARYU90120
Seafoam Islands 1Fgrass159338GOLDUCK38SLOWBRO5580
Victory Road 2Fgrass1005122MACHOP22MACHOP6666
Victory Road 2Fgrass1015124GEODUDE24GEODUDE7474
Victory Road 2Fgrass1023926ZUBAT26ZUBAT4141
Victory Road 2Fgrass1032536ONIX36ONIX9595
Victory Road 2Fgrass1042539ONIX39ONIX9595
Victory Road 2Fgrass1052542ONIX42ONIX9595
Victory Road 2Fgrass1061341MACHOKE41MACHOKE6767
Victory Road 2Fgrass1071340GOLBAT40GOLBAT4242
Victory Road 2Fgrass1081140MAROWAK40MAROWAK105105
Victory Road 2Fgrass109343GRAVELER43GRAVELER7575
Diglett's Cavegrass2005118DIGLETT18DIGLETT5050
Diglett's Cavegrass2015119DIGLETT19DIGLETT5050
Diglett's Cavegrass2023917DIGLETT17DIGLETT5050
Diglett's Cavegrass2032520DIGLETT20DIGLETT5050
Diglett's Cavegrass2042516DIGLETT16DIGLETT5050
Diglett's Cavegrass2052515DIGLETT15DIGLETT5050
Diglett's Cavegrass2061321DIGLETT21DIGLETT5050
Diglett's Cavegrass2071322DIGLETT22DIGLETT5050
Diglett's Cavegrass2081129DUGTRIO29DUGTRIO5151
Diglett's Cavegrass209331DUGTRIO31DUGTRIO5151
Victory Road 3Fgrass1505124MACHOP24MACHOP6666
Victory Road 3Fgrass1515126GEODUDE26GEODUDE7474
Victory Road 3Fgrass1523922ZUBAT22ZUBAT4141
Victory Road 3Fgrass1532542ONIX42ONIX9595
Victory Road 3Fgrass1542540VENOMOTH40VENOMOTH4949
Victory Road 3Fgrass1552545ONIX45ONIX9595
Victory Road 3Fgrass1561343GRAVELER43GRAVELER7575
Victory Road 3Fgrass1571341GOLBAT41GOLBAT4242
Victory Road 3Fgrass1581142MACHOKE42MACHOKE6767
Victory Road 3Fgrass159345MACHOKE45MACHOKE6767
Pokémon Mansion 2Fgrass1005132GROWLITHE32VULPIX5837
Pokémon Mansion 2Fgrass1015134KOFFING34GRIMER10988
Pokémon Mansion 2Fgrass1023934KOFFING34GRIMER10988
Pokémon Mansion 2Fgrass1032530PONYTA30PONYTA7777
Pokémon Mansion 2Fgrass1042530KOFFING30GRIMER10988
Pokémon Mansion 2Fgrass1052532PONYTA32PONYTA7777
Pokémon Mansion 2Fgrass1061330GRIMER30KOFFING88109
Pokémon Mansion 2Fgrass1071328PONYTA28PONYTA7777
Pokémon Mansion 2Fgrass1081139WEEZING39MUK11089
Pokémon Mansion 2Fgrass109337MUK37WEEZING89110
Pokémon Mansion 3Fgrass1005131KOFFING31GRIMER10988
Pokémon Mansion 3Fgrass1015133GROWLITHE33VULPIX5837
Pokémon Mansion 3Fgrass1023935KOFFING35GRIMER10988
Pokémon Mansion 3Fgrass1032532PONYTA32PONYTA7777
Pokémon Mansion 3Fgrass1042534PONYTA34MAGMAR77126
Pokémon Mansion 3Fgrass1052540WEEZING40MUK11089
Pokémon Mansion 3Fgrass1061334GRIMER34KOFFING88109
Pokémon Mansion 3Fgrass1071338WEEZING38MUK11089
Pokémon Mansion 3Fgrass1081136PONYTA36PONYTA7777
Pokémon Mansion 3Fgrass109342MUK42WEEZING89110
Pokémon Mansion B1Fgrass1005133KOFFING33GRIMER10988
Pokémon Mansion B1Fgrass1015131KOFFING31GRIMER10988
Pokémon Mansion B1Fgrass1023935GROWLITHE35VULPIX5837
Pokémon Mansion B1Fgrass1032532PONYTA32PONYTA7777
Pokémon Mansion B1Fgrass1042531KOFFING31GRIMER10988
Pokémon Mansion B1Fgrass1052540WEEZING40MUK11089
Pokémon Mansion B1Fgrass1061334PONYTA34PONYTA7777
Pokémon Mansion B1Fgrass1071335GRIMER35KOFFING88109
Pokémon Mansion B1Fgrass1081142WEEZING38MAGMAR110126
Pokémon Mansion B1Fgrass109342MUK42WEEZING89110
Safari Zone Eastgrass3005124NIDORAN♂24NIDORAN♀3229
Safari Zone Eastgrass3015126DODUO26DODUO8484
Safari Zone Eastgrass3023922PARAS22PARAS4646
Safari Zone Eastgrass3032525EXEGGCUTE25EXEGGCUTE102102
Safari Zone Eastgrass3042533NIDORINO33NIDORINA3330
Safari Zone Eastgrass3052523EXEGGCUTE23EXEGGCUTE102102
Safari Zone Eastgrass3061324NIDORAN♀24NIDORAN♂2932
Safari Zone Eastgrass3071325PARASECT25PARASECT4747
Safari Zone Eastgrass3081125KANGASKHAN25KANGASKHAN115115
Safari Zone Eastgrass309328SCYTHER28PINSIR123127
Safari Zone Northgrass3005122NIDORAN♂22NIDORAN♀3229
Safari Zone Northgrass3015126RHYHORN26RHYHORN111111
Safari Zone Northgrass3023923PARAS23PARAS4646
Safari Zone Northgrass3032525EXEGGCUTE25EXEGGCUTE102102
Safari Zone Northgrass3042530NIDORINO30NIDORINA3330
Safari Zone Northgrass3052527EXEGGCUTE27EXEGGCUTE102102
Safari Zone Northgrass3061330NIDORINA30NIDORINO3033
Safari Zone Northgrass3071332VENOMOTH32VENOMOTH4949
Safari Zone Northgrass3081126CHANSEY26CHANSEY113113
Safari Zone Northgrass309328TAUROS28TAUROS128128
Safari Zone Westgrass3005125NIDORAN♂25NIDORAN♀3229
Safari Zone Westgrass3015126DODUO26DODUO8484
Safari Zone Westgrass3023923VENONAT23VENONAT4848
Safari Zone Westgrass3032524EXEGGCUTE24EXEGGCUTE102102
Safari Zone Westgrass3042533NIDORINO33NIDORINA3330
Safari Zone Westgrass3052526EXEGGCUTE26EXEGGCUTE102102
Safari Zone Westgrass3061325NIDORAN♀25NIDORAN♂2932
Safari Zone Westgrass3071331VENOMOTH31VENOMOTH4949
Safari Zone Westgrass3081126TAUROS26TAUROS128128
Safari Zone Westgrass309328KANGASKHAN28KANGASKHAN115115
Safari Zone Centergrass3005122NIDORAN♂22NIDORAN♀3229
Safari Zone Centergrass3015125RHYHORN25RHYHORN111111
Safari Zone Centergrass3023922VENONAT22VENONAT4848
Safari Zone Centergrass3032524EXEGGCUTE24EXEGGCUTE102102
Safari Zone Centergrass3042531NIDORINO31NIDORINA3330
Safari Zone Centergrass3052525EXEGGCUTE25EXEGGCUTE102102
Safari Zone Centergrass3061331NIDORINA31NIDORINO3033
Safari Zone Centergrass3071330PARASECT30PARASECT4747
Safari Zone Centergrass3081123SCYTHER23PINSIR123127
Safari Zone Centergrass309323CHANSEY23CHANSEY113113
Cerulean Cave 2Fgrass1505151DODRIO51DODRIO8585
Cerulean Cave 2Fgrass1515151VENOMOTH51VENOMOTH4949
Cerulean Cave 2Fgrass1523951KADABRA51KADABRA6464
Cerulean Cave 2Fgrass1532552RHYDON52RHYDON112112
Cerulean Cave 2Fgrass1542552MAROWAK52MAROWAK105105
Cerulean Cave 2Fgrass1552552ELECTRODE52ELECTRODE101101
Cerulean Cave 2Fgrass1561356CHANSEY56CHANSEY113113
Cerulean Cave 2Fgrass1571354WIGGLYTUFF54WIGGLYTUFF4040
Cerulean Cave 2Fgrass1581155DITTO55DITTO132132
Cerulean Cave 2Fgrass159360DITTO60DITTO132132
Cerulean Cave B1Fgrass2505155RHYDON55RHYDON112112
Cerulean Cave B1Fgrass2515155MAROWAK55MAROWAK105105
Cerulean Cave B1Fgrass2523955ELECTRODE55ELECTRODE101101
Cerulean Cave B1Fgrass2532564CHANSEY64CHANSEY113113
Cerulean Cave B1Fgrass2542564PARASECT64PARASECT4747
Cerulean Cave B1Fgrass2552564RAICHU64RAICHU2626
Cerulean Cave B1Fgrass2561357ARBOK57SANDSLASH2428
Cerulean Cave B1Fgrass2571365DITTO65DITTO132132
Cerulean Cave B1Fgrass2581163DITTO63DITTO132132
Cerulean Cave B1Fgrass259367DITTO67DITTO132132
Cerulean Cave 1Fgrass1005146GOLBAT46GOLBAT4242
Cerulean Cave 1Fgrass1015146HYPNO46HYPNO9797
Cerulean Cave 1Fgrass1023946MAGNETON46MAGNETON8282
Cerulean Cave 1Fgrass1032549DODRIO49DODRIO8585
Cerulean Cave 1Fgrass1042549VENOMOTH49VENOMOTH4949
Cerulean Cave 1Fgrass1052552ARBOK52SANDSLASH2428
Cerulean Cave 1Fgrass1061349KADABRA49KADABRA6464
Cerulean Cave 1Fgrass1071352PARASECT52PARASECT4747
Cerulean Cave 1Fgrass1081153RAICHU53RAICHU2626
Cerulean Cave 1Fgrass109353DITTO53DITTO132132
Rock Tunnel B1Fgrass1505116ZUBAT16ZUBAT4141
Rock Tunnel B1Fgrass1515117ZUBAT17ZUBAT4141
Rock Tunnel B1Fgrass1523917GEODUDE17GEODUDE7474
Rock Tunnel B1Fgrass1532515MACHOP15MACHOP6666
Rock Tunnel B1Fgrass1542516GEODUDE16GEODUDE7474
Rock Tunnel B1Fgrass1552518ZUBAT18ZUBAT4141
Rock Tunnel B1Fgrass1561317MACHOP17MACHOP6666
Rock Tunnel B1Fgrass1571317ONIX17ONIX9595
Rock Tunnel B1Fgrass1581113ONIX13ONIX9595
Rock Tunnel B1Fgrass159318GEODUDE18GEODUDE7474
Every place’s ten slots

#Repel

A Repel lasts 10013 steps, a Super Repel 20013, and a Max Repel 25013; a new one replaces whatever was left13. Steps and turns in towns and on paths count as well as those in grass, but the two steps after a battle and the other steps that can’t start one don’t13,11. The step on which it wears off meets nothing13.

While it lasts, a wild Pokémon at or above the first party Pokémon’s level still appears; one below it is turned away, and that step meets nothing6. Battles get rarer, but the roll and the slot are the same as without a Repel6. The first Pokémon counts even if it has fainted6. On Mt. Moon 1F, a Repel ahead of a Pokémon at the Clefairy’s level cuts the battles per Clefairy from 85.37 to 607, but the walk only from about 23507 steps to 23007,7.

#Fishing

A rod works facing water or a shore, outside battle, and not while surfing. A hooked Pokémon starts its battle at once, so neither a Repel nor the steps after a battle stop it14. The Old Rod always hooks a level-5 Magikarp15. The Good Rod bites 33.316% of the time, a Goldeen or a Poliwag, on any map16,17.

The Super Rod hooks from a list of two to four Pokémon that depends on the map, and finds nothing on maps without one18. The longer the list, the more often it bites: 5019% with four, 42.919% with three, and 33.319% with two19. Its only Dratini are in the Safari Zone18.

MapLevelSpecies
Pallet Town15TENTACOOL
Pallet Town15POLIWAG
Viridian City15TENTACOOL
Viridian City15POLIWAG
Cerulean City15PSYDUCK
Cerulean City15GOLDEEN
Cerulean City15KRABBY
Vermilion City15KRABBY
Vermilion City15SHELLDER
Celadon City23POLIWHIRL
Celadon City15SLOWPOKE
Fuchsia City23SEAKING
Fuchsia City15KRABBY
Fuchsia City15GOLDEEN
Fuchsia City15MAGIKARP
Cinnabar Island15STARYU
Cinnabar Island15HORSEA
Cinnabar Island15SHELLDER
Cinnabar Island15GOLDEEN
Route 415PSYDUCK
Route 415GOLDEEN
Route 415KRABBY
Route 615KRABBY
Route 615SHELLDER
Route 1023POLIWHIRL
Route 1015SLOWPOKE
Route 1115KRABBY
Route 1115SHELLDER
Route 125TENTACOOL
Route 1215KRABBY
Route 1215GOLDEEN
Route 1215MAGIKARP
Route 135TENTACOOL
Route 1315KRABBY
Route 1315GOLDEEN
Route 1315MAGIKARP
Route 175TENTACOOL
Route 1715KRABBY
Route 1715GOLDEEN
Route 1715MAGIKARP
Route 185TENTACOOL
Route 1815KRABBY
Route 1815GOLDEEN
Route 1815MAGIKARP
Route 1915STARYU
Route 1915HORSEA
Route 1915SHELLDER
Route 1915GOLDEEN
Route 2015STARYU
Route 2015HORSEA
Route 2015SHELLDER
Route 2015GOLDEEN
Route 2115STARYU
Route 2115HORSEA
Route 2115SHELLDER
Route 2115GOLDEEN
Route 2215GOLDEEN
Route 2215POLIWAG
Route 2323SLOWBRO
Route 2323SEAKING
Route 2323KINGLER
Route 2323SEADRA
Route 2415PSYDUCK
Route 2415GOLDEEN
Route 2415KRABBY
Route 2515PSYDUCK
Route 2515GOLDEEN
Route 2515KRABBY
Cerulean Gym15PSYDUCK
Cerulean Gym15GOLDEEN
Cerulean Gym15KRABBY
Vermilion Dock15KRABBY
Vermilion Dock15SHELLDER
Seafoam Islands B3F15STARYU
Seafoam Islands B3F15HORSEA
Seafoam Islands B3F15SHELLDER
Seafoam Islands B3F15GOLDEEN
Seafoam Islands B4F15STARYU
Seafoam Islands B4F15HORSEA
Seafoam Islands B4F15SHELLDER
Seafoam Islands B4F15GOLDEEN
Safari Zone East15DRATINI
Safari Zone East15KRABBY
Safari Zone East15PSYDUCK
Safari Zone East15SLOWPOKE
Safari Zone North15DRATINI
Safari Zone North15KRABBY
Safari Zone North15PSYDUCK
Safari Zone North15SLOWPOKE
Safari Zone West15DRATINI
Safari Zone West15KRABBY
Safari Zone West15PSYDUCK
Safari Zone West15SLOWPOKE
Safari Zone Center15DRATINI
Safari Zone Center15KRABBY
Safari Zone Center15PSYDUCK
Safari Zone Center15SLOWPOKE
Cerulean Cave 2F23SLOWBRO
Cerulean Cave 2F23SEAKING
Cerulean Cave 2F23KINGLER
Cerulean Cave 2F23SEADRA
Cerulean Cave B1F23SLOWBRO
Cerulean Cave B1F23SEAKING
Cerulean Cave B1F23KINGLER
Cerulean Cave B1F23SEADRA
Cerulean Cave 1F23SLOWBRO
Cerulean Cave 1F23SEAKING
Cerulean Cave 1F23KINGLER
Cerulean Cave 1F23SEADRA
Every Super Rod list, by map

References

  1. ^ abCodepret/pokeredwild_encounters.asm 26–53; Route1.asm 1–2
    How we know
    engine/battle/wild_encounters.asm at af51989
    Our readingthe step's tile picks the rate (not all quoted)26–33a random byte not below the rate: no battle50–53
    1Route1WildMons:
    2	def_grass_wildmons 25 ; encounter rate
    
    data/wild/maps/Route1.asm lines 1–2 at af51989 · upstream ↗

    Claim page

  2. ^ abcCode
    How we know

    Claim page

  3. ^ abcdefgCode
    How we know

    Claim page

  4. ^ abcCodepret/pokeredwild_encounters.asm 54–62; probabilities.asm 11–28
    How we know
    engine/battle/wild_encounters.asm at af51989
    Our readingb ← the second random byte54–55read the slot table (pokered-wild/slot-pick)56
    17	wild_chance 51 ; 51/256 = 19.9% chance of slot 0
    ⋮
    26	wild_chance  3 ;  3/256 =  1.2% chance of slot 9
    
    data/wild/probabilities.asm lines 11–28 at af51989 · upstream ↗

    Claim page

  5. ^ abCodepret/pokeredRoute1.asm 1–16; Route2.asm 1–25; +58 files
    How we know
    1Route1WildMons:
    2	def_grass_wildmons 25 ; encounter rate
    3	db  3, PIDGEY
    4	db  3, RATTATA
    5	db  3, RATTATA
    6	db  2, RATTATA
    7	db  2, PIDGEY
    8	db  3, PIDGEY
    9	db  3, PIDGEY
    10	db  4, RATTATA
    11	db  4, PIDGEY
    12	db  5, PIDGEY
    ⋮
    
    data/wild/maps/Route1.asm lines 1–16 at af51989 · upstream ↗
    1Route2WildMons:
    2	def_grass_wildmons 25 ; encounter rate
    3	db  3, RATTATA
    4	db  3, PIDGEY
    5	db  4, PIDGEY
    6	db  4, RATTATA
    7	db  5, PIDGEY
    8IF DEF(_RED)
    9	db  3, WEEDLE
    10	db  2, RATTATA
    11	db  5, RATTATA
    12	db  4, WEEDLE
    ⋮
    
    data/wild/maps/Route2.asm lines 1–25 at af51989 · upstream ↗
    1Route3WildMons:
    2	def_grass_wildmons 20 ; encounter rate
    3	db  6, PIDGEY
    4	db  5, SPEAROW
    5	db  7, PIDGEY
    6	db  6, SPEAROW
    7	db  7, SPEAROW
    8	db  8, PIDGEY
    9	db  8, SPEAROW
    10	db  3, JIGGLYPUFF
    11	db  5, JIGGLYPUFF
    12	db  7, JIGGLYPUFF
    ⋮
    
    data/wild/maps/Route3.asm lines 1–16 at af51989 · upstream ↗
    engine/overworld/wild_mons.asm at af51989
    Our readingfind the map's entry in the pointer table1–12grass rate ← the list's first byte13–14rate 0: skip to the water part15–16else copy the 20 bytes after it to the grass list17–23water rate ← the next byte25–26rate 0: done27–28else copy the 20 bytes after it to the water list29–31

    57 more excerpts on the claim page

  6. ^ abcdCodepret/pokeredwild_encounters.asm 81–89
    How we know
    engine/battle/wild_encounters.asm at af51989
    Our readingno Repel steps left: battle81–83b ← the first party Pokémon's level84–85the wild level below b: no encounter86–88else battle89

    Claim page

  7. ^ abcdefghCode
    How we know

    Claim page

  8. ^ abCodepret/pokeredwild_encounters.asm 26–47; tileset_headers.asm 1–36; +34 files
    How we know
    engine/battle/wild_encounters.asm at af51989
    Our readingtile ← the half-block's bottom-right tile (by the comment)26–29the tileset's grass tile: rate ← the grass rate30–33tile $14, water (by the comment): rate ← the water rate34–37an outdoor map (by the comment): no encounter41–43the forest tileset: no encounter44–46otherwise: rate ← the grass rate47
    1MACRO tileset
    2	db BANK(\1_GFX)
    3	dw \1_Block, \1_GFX, \1_Coll
    4	db \2, \3, \4 ; counter tiles
    5	db \5         ; grass tile
    6	db \6         ; animations (TILEANIM_* value)
    7ENDM
    ⋮
    9Tilesets:
    10	table_width 12
    11	; name, 3 counter tiles, grass tile, animations
    12	tileset Overworld,    -1, -1, -1, $52, TILEANIM_WATER_FLOWER
    13	tileset RedsHouse1,   -1, -1, -1,  -1, TILEANIM_NONE
    ⋮
    
    data/tilesets/tileset_headers.asm lines 1–36 at af51989 · upstream ↗
    66	map_const ROUTE_25,                      30,  9 ; $24
    ⋮
    68DEF FIRST_INDOOR_MAP EQU const_value
    69	map_const REDS_HOUSE_1F,                  4,  4 ; $25
    
    constants/map_constants.asm lines 66–69 at af51989 · upstream ↗
    1	map_header ViridianForest, VIRIDIAN_FOREST, FOREST
    
    data/maps/headers/ViridianForest.asm line 1 at af51989 · upstream ↗
    home/overworld.asm at af51989
    Our readingno direction held: turn check ← 1136–137 a direction was held: last direction ← it138–142 held direction ← none143–144a direction pressed: new direction ← it180scripted movement: no turn, walk181–183turn check 0 (already moving): no turn, walk184–186the last direction again: no turn, walk187–191a reversal: face a side first (by the comment)192–223turn check − 1, to 0; face the new direction224–231try a battle with no step (NewBattle, its check)232a battle happened: the after-battle handling233else back to the loop234

    31 more excerpts on the claim page

  9. ^Codepret/pokeredwild_mons.asm 24–28; wild_encounters.asm 34–37, 48–53
    How we know
    engine/overworld/wild_mons.asm at af51989
    Our readingwater rate ← the list's water byte25–26rate 0: no water list27–28
    engine/battle/wild_encounters.asm at af51989
    Our readingtile $14 (water, by the comment): rate ← the water rate34–37a random byte not below the rate: no encounter50–53

    Claim page

  10. ^Codepret/pokeredwild_encounters.asm 63–73
    How we know
    engine/battle/wild_encounters.asm at af51989
    Our readingthe slot's offset into the list (from the slot table)65list ← the grass list66the bottom-left tile is $14: list ← the water list67–70

    Claim page

  11. ^ abcCodepret/pokeredwild_encounters.asm 1–18; core.asm 6661–6664
    How we know
    engine/battle/wild_encounters.asm at af51989
    Our readingan NPC movement script is set (by its label): none4–6a door exit, ledge jump, or fishing (by the comment): none7–9on a door or warp tile (by its label): none10–15just outside the map (by its label): none17–18
    engine/battle/core.asm at af51989
    Our readingno-battle steps left: no encounter check6661–6663else the encounter check (wild_encounters.asm)6664

    Claim page

  12. ^Codepret/pokeredend_of_battle.asm 46–70; overworld.asm 341–358, 756–770, 6–17, 291–320, 321–340, 362–371; +2 files
    How we know
    engine/battle/end_of_battle.asm at af51989
    Our readingclear the low-health alarm and channel 5's sound47–49clear the in-battle value, the battle type, and other values50–62clear the battle status block, a byte at a time63–68set the encounter cooldown flag69–70
    home/overworld.asm at af51989
    Our readingset the battle-over-or-blackout flag341–342if the map is Oak's lab: skip the fainting check343–345if the party-alive test (its lines not quoted) returns 0: black out346–349no fainting check: wait 10 frames (the delay's lines not quoted)351–352 load the map (EnterMap, below)353black out: in-battle value ← lost355–356 run the map's script (its lines not quoted)357 go to the blackout routine (below)358fade to black and stop the music (their lines not quoted)759–761clear the battle-over-or-blackout flag762–763switch to the reset routine's ROM bank (by the comment, the warp's too)764–766call routines (their lines not quoted) named for: resetting status and halving the money767 preparing the special warp768 the map's music769go to the warp's map load (SpecialEnterMap, below)770
    engine/menus/main_menu.asm at af51989
    Our readingclear the button bytes and the Cable Club destination328–332start the game timer counting333–334reset the player's sprite (its lines not quoted); wait 20 frames335–337if the entering-Cable-Club flag is set: return338–340load the map (EnterMap, below)341
    home/overworld.asm at af51989
    Our readingignore all buttons8–9load the map's data, clear the map-entry values (their lines not quoted)10–11if the cooldown flag is set: no-battle steps ← 312–16if the movement is scripted (simulated button presses): skip the counting292–294step counter (a separate one) − 1296–297if the cooldown flag is set:298–300 no-battle steps − 1301–302 if that reaches 0: clear the cooldown flag303–305in the Safari Zone:307–308 check its step limit (its lines not quoted)309 if the Safari game is over: warp out310–312if the in-battle value isn't 0: go to the warp check314–316apply poison damage outside battle (its lines not quoted)317if the out-of-battle blackout flag is set: black out318–320try a battle (NewBattle, below)322clear the standing-on-warp flag323–324if no battle happened (carry clear): go to the warp check325after a battle: clear the talked-to-trainer and trainer-battle flags327–330 set the two map-loaded flags; clear the held buttons331–335 in Cinnabar Gym: set event $2A7 (unnamed upstream)336–339if the player is on a dungeon warp: no battle363–365if the game is moving the player (its test's lines not quoted): no battle366–367if the no-battles flag is set: no battle368–370go to the battle setup (InitBattle, below)371
    engine/battle/core.asm at af51989
    Our readingif the opponent byte is 0 (no set opponent): pick a wild one (below)6643–6645if debug mode is on and B is held: return, no wild battle6654–6659if the no-battle steps aren't 0: return, no wild battle6661–6663try a wild encounter (its lines not quoted)6664if the subtraction before it (not quoted) set carry: go to the wild battle's setup6676go to the shared battle setup (below)6693
    6734; common code that executes after init battle code specific to trainer or wild battles
    6735_InitBattleCommon:
    
    engine/battle/core.asm lines 6733–6735 at af51989 · upstream ↗
    engine/battle/core.asm at af51989
    Our readingrun the battle (its lines not quoted)6763then the end of battle (EndOfBattle, the first entry)6764

    Claim page

  13. ^ abcdefCodepret/pokereditem_effects.asm 1532–1541, 1622–1628; wild_encounters.asm 19–25, 90–99; +1 files
    How we know
    engine/items/item_effects.asm at af51989
    Our readingRepel: steps ← 1001532–1533in battle: refuse (by its label)1535–1538Repel steps ← that count1539–1541Super Repel: steps ← 200, as Repel1622–1624Max Repel: steps ← 250, as Repel1626–1628
    engine/battle/wild_encounters.asm at af51989
    Our readingRepel steps 0: go on19–21Repel steps − 1; reaching 0: last step22–23else store the count24last step: Repel steps ← 090–91show the wore-off text92–95no encounter96–99
    20_RepelWoreOffText::
    21	text "REPEL's effect"
    22	line "wore off."
    23	done
    
    data/text/text_4.asm lines 20–23 at af51989 · upstream ↗

    Claim page

  14. ^Codepret/pokereditem_effects.asm 1891–1916, 2826–2851, 1866–1877; overworld.asm 64–66; +1 files
    How we know
    engine/items/item_effects.asm at af51989
    Our readingin battle: can't fish1894–1898the tile ahead isn't shore or water (below): can't fish1900–1901surfing: can't fish1902–1904else print the use text, play a sound, wait 80 frames1905–1913a tileset without water: no2830–2834Vermilion Dock's tileset: water only2835–2838an eastern shore tile ($48 or $32): yes2839–2842the water tile, $14: yes2844–2845a bite: the opponent ← the species, at its level1866–1877
    home/overworld.asm at af51989
    Our readingan opponent is set: start a battle64–66
    engine/battle/core.asm at af51989
    Our readingno opponent set: the wild encounter check6643–6645else battle that opponent6647–6651

    Claim page

  15. ^Codepret/pokereditem_effects.asm 1826–1831
    How we know
    engine/items/item_effects.asm at af51989
    Our readingcan't fish here: refuse (by its label)1827–1828level 5, Magikarp; a bite1829–1831

    Claim page

  16. ^ abCodepret/pokereditem_effects.asm 1833–1857
    How we know
    engine/items/item_effects.asm at af51989
    Our readingcan't fish here: refuse (by its label)1834–1835draw a random byte; shift out its low bit1836–1838low bit 1: no bite1839n ← the next two bits; n of 2 or 3: draw again1840–1842level, species ← the list's entry n1844–1851carry clear: a bite; set: none1852–1857

    Claim page

  17. ^Codepret/pokeredgood_rod.asm 1–5
    How we know
    1; random choice of 2 good rod encounters
    2GoodRodMons:
    3	; level, species
    4	db 10, GOLDEEN
    5	db 10, POLIWAG
    
    data/wild/good_rod.asm lines 1–5 at af51989 · upstream ↗

    Claim page

  18. ^ abCodepret/pokeredsuper_rod.asm 1–101
    How we know
    1; super rod encounters
    2SuperRodData:
    3	; map, fishing group
    4	dbw PALLET_TOWN,         .Group1
    5	dbw VIRIDIAN_CITY,       .Group1
    6	dbw CERULEAN_CITY,       .Group3
    7	dbw VERMILION_CITY,      .Group4
    8	dbw CELADON_CITY,        .Group5
    9	dbw FUCHSIA_CITY,        .Group10
    10	dbw CINNABAR_ISLAND,     .Group8
    11	dbw ROUTE_4,             .Group3
    12	dbw ROUTE_6,             .Group4
    ⋮
    
    data/wild/super_rod.asm lines 1–101 at af51989 · upstream ↗

    Claim page

  19. ^ abcdCodepret/pokereditem_effects.asm 2855–2898, 1861–1865
    How we know
    engine/items/item_effects.asm at af51989
    Our readingthe map has no list: nothing here2859–2865b ← the list's size2867–2877draw a random byte; low bit 1: no bite2880–2883n ← the next two bits; n not below b: draw again2885–2887level, species ← entry n; a bite2889–2898can't fish here: refuse (by its label)1862–1863read the map's list (above)1864–1865

    Claim page

Sources

Code